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The Pineapple Juice Solution, Part 2

Debra Wink's picture
Debra Wink

The Pineapple Juice Solution, Part 2

Pineapple juice is a simple solution to a problem that many people encounter while trying to start a sourdough seed culture from scratch. Oftentimes, a new culture will appear to start off very strong, only to die a day or two later. The early expansion is caused by a prolific gas-producing bacterium which many mistake for yeast. Pineapple juice can be added to flour instead of water at the beginning, to insure against unwanted bacteria and the problems they leave in their wake. It doesn't change the end result, but it does seem to keep things on the track to finish on time. Part 1 tells the story of where the pineapple remedy comes from and how it was conceived. The rest of the story probes deeper into how it all works. But first, here is a recap of the key patterns revealed by notes and data collected during experimental trials:

  • When starters expanded significantly on the second day, a period of stillness followed, and the appearance of yeast was delayed.
  • Gas-producing bacteria stopped growing when the pH dropped to 4.5, but yeast growth didn't begin until the pH fell to around 3.5, accounting for the period of stillness.
  • Lowering the pH in the initial mixture, by adding ascorbic acid or by replacing the water with pineapple juice, kept gas-producing bacteria from growing and brought about a more timely and predictable result.

But it wasn't enough just to find a fix. The problem-solving efforts of my team were creating a buzz which we hadn't anticipated and this thing, like the seed cultures we were creating, was taking on a life of its own. Some were jumping to premature conclusions, and speculation seemed to be spreading as fact. It made me very uncomfortable, because I'd rather be dispelling myths than adding to them. I wanted to find some real answers, and find them fast, so I started making phone calls. I found two local labs that could help me out. One had the capability to identify leuconostocs, and the other to detect lactobacilli and other bacteria of interest. I submitted samples of a day two starter during the big expansion. Both labs found that there were three organisms growing. But there were no lactobacilli or yeasts found, which supports what I observed time after time on microscopic examination. My gas-producer was identified as Leuconostoc citreum. At the time, I couldn't find much information specific to this organism, although it seems to share many characteristics with other Leuconostoc species found in foods. Most will not grow below pH 4.8, and this one doesn't appear to be an exception.

Until recently, I could only theorize that the Leuconostoc may actively hinder the process, because the pattern supports it, and because it's not uncommon for microorganisms to produce substances which inhibit competitors. But in updating this article, a new search of the scientific literature finally uncovered the piece of the puzzle I was looking for. Who would have thought the answers would be found in kimchi and sake? It turns out that kimchi fermentation has a lot in common with sourdough development, and mirrors the early days of the seed culture process. Leuconostoc citreum plays a dominant role in the early and mid-phases of fermentation where it causes a slow and prolonged drop in pH, and retards the growth of other lactic acid bacteria.[1] In a study on sake fermentation, Leuconostoc citreum was found to produce bacteriocins (bacterially-produced antibiotic proteins) which inhibit the growth of similar lactic acid bacteria (i.e., lactobacilli).[2] It appears that these bacteriocins linger for a time even after the organism stops growing, although their effect is diluted through successive feeding. A dosage effect would explain nicely the apparent relationship between the vigor with which this bacterium flairs up initially, and the number of days the starter remains still afterward. The higher the rise, the longer it seems to take to recover.

In addition to Leuconostoc citreum, there was also a large amount of Aerococcus viridans. The first lab I visited found Leuconostoc to be in the greatest quantity, but Aerococcus was multiplying so fast that it soon passed the Leuconostoc in number. That is important, and could very well have contributed to the delayed progress. Even though Aerococcus doesn't produce gas, and so was not responsible for any of the expansion, it is not much of an acid producer either. So while it was using up a large share of the available sugars, it was not helping the pH to fall. Aerococcus is an occasional spoilage organism in unpasteurized milk, which is the extent of information that I have found on its involvement in foods. Its lower limit is not given in my reference books, but since pineapple juice seems to keep it at bay, I suspect that it must be in the same ballpark with leuconostocs. I'm still not sure how big a part each of these organisms plays in slowing the progress of a seed culture, but lowering the pH at the outset seems to be a blanket fix.

I mentioned in Part 1 that some of the bacteria were flipping, twirling and zipping around under the microscope. Those were Enterobacter cloacae. Enterobacter produces gas, but since it was present in only a scant amount compared to the others, I think it safe to say that the Leuconostoc was responsible for the majority of it. However, Enterobacter contributes to an unpleasant odor, as do Aerococcus and Leuconostoc. Because some people report a very stinky smell and others not as much, I'd have to say that even among starters that grow Leuconostoc, not all necessarily have the same combination of bacteria. There are others that can grow as well. Results vary from flour to flour and year to year, because the number and species of microorganisms are influenced by conditions relating to weather and grain crop production.[3] I wish I could have all the organisms identified at every stage, but there aren't any laboratories in my area that are equipped to identify wild yeasts or sourdough bacteria. And even if they could, the cost would be prohibitive. I was fortunate to be in a position to have two of the organisms identified as a professional courtesy.

With the additional information, and having watched the drama unfold under the microscope, I started seeing the seed culture process not as good guys out-competing bad or gradually increasing in number, but as a natural succession of microorganisms that pave the way for "the good guys" in the way that they transform their environment. There are bacteria in flour that prefer the more neutral pH of freshly mixed flour and water (like Leuconostoc and company). They are the first to start growing, some producing acids as by-products. This lowers the pH, and other bacteria begin to grow; they produce their acids, lowering the pH even more. It soon becomes too acidic for the first batch and they stop growing. One group slows down and drops out as the next is picking up and taking off. Each has its time, and each lays the groundwork for the next. It's much more like a relay than a microbial free-for-all. The baton is passed to the next group in line as conditions become suitable for them. The acidity increases a bit more with each pass, and the more acid-loving bacteria can eventually take over. The appearance of yeast seems to be tied in some way to low pH---maybe directly, maybe indirectly, but the correlation shows that it isn't random in the way that "catching" yeast from the air would be, or their gradually increasing in number.

In the late fall/early winter of 2004, I was coaching a group of women on Cookstalk, Taunton's Fine Cooking forum, and I noticed something else. My starters sort of liquefy the day before yeast starts to grow. Gluten disappears, which shows the work of proteolytic enzymes. At first I thought it signaled the appearance of lactobacilli and their proteases. But now I think it was simply an indicator that the pH had dropped low enough to activate aspartic proteinases, pH-sensitive enzymes abundant in wheat.[4] Because I prefer to seed a new culture with whole grain flour for at least three days, there are more cereal enzymes present than in a starter fed with white flour (most of them are removed with bran in the milling process). But either way, it is a good sign of Lactobacillus activity, whether by production of bacterial proteases or by the organism's effect on pH and activation of cereal proteases.

The starters were developing a little more slowly this time around, which inspired me to describe the different stages that a new culture transitions through, rather than try and pin it to a time frame. Room temperature is different from one kitchen to the next, as well as season to season. Sometimes rye flour finishes faster, sometimes whole wheat is faster. Sometimes a culture doesn't start producing its own acid for the first two days instead of one. Because this process involves variable live cultures under variable conditions, it doesn't always work in a prescribed number of days, but it follows a predictable pattern. While this has been a discovery process for me, it is not a new discovery:

"There has been nice work done in Rudi Vogel's lab on the microflora of a freshly started sourdough: first, there are enterobacteria (Escherichia coli, Salmonella, Enterobacter), highly undesirable organisms that stink terribly. Then there are homofermentative lactobacilli (good lactic acid producers, but they don't produce gas or acetic acid), then acid-tolerant, heterofermentative lactobacilli that make lactic and acetic acid, as well as CO2. I think this took about forty-eight hours at 30ºC in Vogel's study. The stink at the beginning does not matter as the organisms will be diluted out or die eventually. No L. sanfranciscensis appears by forty-eight hours, though: these will occur only after repeated refreshments. Peter Stolz told me that it takes about two weeks of repeated inoculations to get a good 'sanfranciscensis' sourdough."[5]

That paragraph didn't have any special significance for me until I had gotten to this point. But when I read it again, I had one of those aha moments. Not only did this describe a succession, but it filled in some of the blanks, and I could see clearly how all these microorganisms related to the four phases I had defined. Here is the updated version marrying the two. You don't need a microscope for this, because there are outward signs which serve as useful indicators of progress.

The First Phase:
For the first day or so, nothing really happens that is detectable to the human senses. It doesn't taste any tangier or develop bubbles. It remains looking much the same as when it was mixed, except a little lighter in color if an acid was used, and a little darker if not. While nothing appears to be happening, the first wave of bacteria (determined by pH and the microflora in the flour) are waking up, sensing their new environment and preparing to grow. This phase usually lasts about one day, sometimes two.

The Second Phase:
The starter will begin producing its own acid and develop a tangy taste (although it might be difficult to distinguish from pineapple juice). Lactic acid bacteria are actively growing at this point. When using only water, this phase represents two waves of microbes---first Leuconostoc and associates, followed by homofermentative lactobacilli and possibly other lactic acid bacteria. By controlling the pH, you can by-pass the leuconostocs and other "highly undesirable organisms that stink terribly," and skip to the second wave. It will get bubbly and expand only if the pH is not low enough to prevent growth of gassy bacteria, otherwise there won't be much to see. There probably won't be much gluten degradation, and it may smell a little different, but it shouldn't smell particularly foul unless started with plain water. This phase can last one to three days or more. If it is going to get hung up anywhere, this is the place it usually happens, especially if it is put on a white flour diet too soon. If after three days in this phase, it still doesn't become more sour and show signs of progress, the best thing to do is switch back to whole grain flour. Whole grain has a much higher microbial count to re-seed the culture and get it moving again. If that doesn't do it, skip a feeding or two to allow the acidity to build.

The Third Phase:
The starter will become very tart like lemon juice---an indication of more acid production by more acid-tolerant bacteria. The gluten may disappear and tiny bubbles become more noticeable. These are signs that heterofermentative lactobacilli have picked up the baton. Once a starter becomes really sour, it usually transitions into phase four within a day or two. Note that lactic acid doesn't have much aroma, and so smell is not a reliable way to judge the level of sourness. If it gets stuck here for 48 hours or more, make sure there's still enough whole grain in the mix and give it more time between refreshments.

The Fourth Phase:
Yeast start to grow and populate the starter relatively quickly at this point. It will expand with gas bubbles all over and begin to take on the yeasty smell of bread or beer.

This pattern suggests that wild yeasts are activated by low pH. Or perhaps the activator is something else produced by lactobacilli, but it happens predictably at this point for me, as long as the whole grain flour has not been diluted out. There may be some variation among wild yeasts as to the exact pH or activating substance. I have been unable to find the answer in scientific literature, and my contact at Lallemand did not know. I have only found studies done with cultivated strains of Saccharomyces cerevisiae, which don't seem to require much more than a fermentable sugar (and may explain why seed cultures take off much quicker in a bakery environment where baker's yeast is everywhere). The most useful information I have found on the subject is this, about microbial spores in general:

"Although spores are metabolically dormant and can remain in this state for many years, if given the proper stimulus they can return to active metabolism within minutes through the process of spore germination. A spore population will often initiate germination more rapidly and completely if activated prior to addition of a germinant. However, the requirement for activation varies widely among spores of different species. A number of agents cause spore activation, including low pH and many chemicals... The initiation of spore germination in different species can be triggered by a wide variety of compounds, including nucleosides, amino acids, sugars, salts, DPA, and long-chain alkylamines, although within a species the requirements are more specific. The precise mechanism whereby these compounds trigger spore germination is not clear."[6]

What this means is that for dormant cells to return to active growth (germinate), they need to break dormancy (activate) which is initiated by different things for different species. In the case of these wild sourdough yeasts, if all they needed were food or oxygen, which are there from the get-go, then they would start growing immediately. The fact that they don't, is probably why many people think they need to be caught from the air, or that large quantities of flour must be used to round up enough of them. There are enough dormant cells present even in relatively small quantities of whole grain flour, but it's like a game of Simon Says. You can try to coax them into growing, with food and all the things you may fancy to be good for actively growing yeast. But they're not active. They are dormant, and will remain so until they receive the right message from their surroundings. Compare this to the plant seed that sits in soil all winter long, waiting until spring to sprout, when conditions are most favorable. Is it a survival mechanism? I don't know, but waiting for the pH to drop does increase the likelihood that the yeast will wake up in the company of lactobacilli, with which they seem to share a complex and mutually beneficial relationship. It is also important to point out here that active sourdough yeasts thrive in a much wider pH range than what appears to be required for activation of dormant cells. The point to keep in mind is that active and dormant cells are physiologically and metabolically different, and so their needs are different.

This pattern of growth is not unique to the formula in the Bread Baker's Apprentice. I have seen the same progression, in whole or in part, with all the starter formulas I've tried. And it doesn't really matter how much flour you start with. In fact this can be done with very small quantities of flour. All else being equal, it proceeds just as fast with a teaspoon as it does with a pound. Procedures that call for two or three feedings per day, or large refreshments before yeast are active, can actually get in the way of the process. Overfeeding unnecessarily dilutes the acid, which slows the drop in pH, and keeps it from moving through the succession of microorganisms in the timeliest manner. But while it can take up to two weeks or more this way, with Mother Nature as the driving force, things do fall in line eventually. It's just a question of when. Three to five days is about all it really takes to reach the yeast activation stage at average room temperature, somewhat longer if Leuconostoc and associates grow. The strategy is quite different from reviving a neglected starter, which is likely to have an overabundance of acid, and a large population of yeast and sourdough bacteria, however sluggish they may be.

So, what can we do instead to facilitate the process? Start by providing conditions for the first two to three days which are favorable to lactic acid bacteria. A warm spot if you can easily manage one (but not too much higher than 80ºF), and a reasonably high hydration (at least 100%). Use pineapple juice if you like, to bypass the first round of bacteria. (Or use water if you prefer, and don't mind the odors and delay.) Feed with whole grain flour until yeast are actively growing, not for the wider spectrum of sugars it may offer, but for its higher numbers of yeast and lactic acid bacteria to seed each phase in its turn. Don't feed too much or too frequently, so as to allow the acids to accumulate and the pH to fall more rapidly. The ideal feeding quantity and frequency would depend on the temperature, hydration, and how fast the pH is falling. However, I usually recommend once a day at room temperature, simply because it is the easiest to manage, it works, and the daily manipulation helps to keep mold from getting started. Mold is the biggest stumbling block for procedures in which a young mixture is allowed to sit idle for two or three days at a time. Turning surface mold spores into the center by re-kneading or stirring and scraping down the sides daily, is the best way to get around it. Mold is not inhibited by low pH or pineapple juice, and anti-mold properties don't fully develop until sourdough is well established.

While you don't actually need a formula to do this, no article on making sourdough starter would be complete without one. This procedure was designed with simplicity in mind, to be efficient, effective, and to minimize waste. It was developed with the participation of four willing and very patient women whom I worked with online---DJ Anderson, Karen Rolfe, Deanna Schneider and the still-anonymous 'lorian,' whose plea for help is what renewed the quest to find a better way. I learned a great deal from the feedback they and others gave me as we worked out the kinks, and this formula is a tribute to them.

There is nothing magic about the two tablespoons of measure used throughout the first three days. Equal weights didn't provide a high enough ratio of acid to flour to suit me, and equal volumes did. Two tablespoons is enough to mix easily without being overly wasteful (and just happens to be the volume of an eighth-cup coffee scoop, which is what I kept on the counter next to the flour and seed culture for quick, easy feeding). If you insist on weighing, make it about 15 gm flour and 30 gm juice. These first few days don't really benefit from being particularly fussy with odd or precise measuring, so make it easy on yourself. Keep it simple, and let Mother Nature do the rest.

Day 1: mix...
2 tablespoons whole grain flour* (wheat or rye)
2 tablespoons pineapple juice, orange juice, or apple cider

Day 2: add...
2 tablespoons whole grain flour*
2 tablespoons juice or cider

Day 3: add...
2 tablespoons whole grain flour*
2 tablespoons juice or cider

Day 4: (and once daily until it starts to expand and smell yeasty), mix . . .
2 oz. of the starter (1/4 cup after stirring down -- discard the rest)
1 oz. whole grain flour* (scant 1/4 cup)
1 oz. water (2 tablespoons)

* Organic is not a requirement, nor does it need to be freshly ground.

On average, yeast begin to grow on day 3 or 4 in the warmer months, and on day 4 or 5 during colder times of the year, but results vary by circumstance. Feed once a day, taking care not to leave mold-promoting residue clinging to the sides or lid of your bowl or container, and refer back to the different phases to track progress---particularly if it gets stuck in second phase or shows no progress for 3 or more days. Once you have yeast growing (but not before), you can and should step up the feeding to two or three times a day, and/or give it bigger refreshments. Before yeast, don't feed too much; after yeast, don't feed too little. You can feed the starter/seed culture whatever you would like at this point. White flour, either bread or a strong unbleached all-purpose like King Arthur or a Canadian brand will turn it into a general-purpose white sourdough starter. Feed it rye flour if you want a rye sour, or whole wheat, if you want to make 100% whole wheat breads. If you're new to sourdough, a white starter is the best place to start.

This is the point at which I generally defer to the sourdough experts. There are several good books on sourdough which address the topic of starter maintenance and how to use it in bread. There are many different approaches. Just keep in mind that the first days of the seed culture process have nothing to do with developing flavor or even fostering the most desirable species. The object is simply to move through the succession and get the starter up and running. The fine-tuning begins there. Once yeast are growing well, choose the hydration, temperature and feeding routine that suits you, and the populations will shift in response to the flour and conditions that you set up for maintenance.

One more thing I have found is that with regular feeding at room temperature, new starters seem to improve and get more fragrant right around the two week mark. Maybe this coincides with the appearance of Lactobacillus sanfranciscensis mentioned previously, or another highly adapted sourdough species. A Fifth Phase, and beyond? Obviously, there is still more to learn.   -Debra Wink


1. Choi, In-Kwon, Seok-Ho  Jung, Bong-Joon Kim, Sae-Young Park, Jeongho Kim, and Hong-Ui Han. 2003. Novel Leuconostoc citreum starter culture system for the fermentation of kimchi, a fermented cabbage product. Antonie van Leeuwenhoek  84:247-253.

2. Kurose, N., T. Asano, S. Kawakita, and S. Tarumi. 2004. Isolation and characterization of psychotrophic Leuconostoc citreum isolated from rice koji. Seibutsu-kogaku Kaishi 82:183-190.

3. Doyle, Michael P., Larry R. Beuchat, and Thomas J. Montville. 2001. Fruits, Vegetables, and Grains, p. 135. Food Microbiology Fundamentals and Frontiers, 2nd ed. American Society for Microbiology Press, Washington, DC.

4. Katina, Kati. 2005. Sourdough: a tool for the improved flavour, texture and shelf-life of wheat bread, p. 23.VTT Technical Research Centre of Finland.

5. Wing, Daniel, and Alan Scott. 1999. Baker's Resource: Sourdough Microbiology, p. 231. The bread Builders. Chelsea Green Publishing Company, White River Junction, VT.

6. Doyle, Michael P., Larry R. Beuchat, and Thomas J. Montville. 2001. Spores and Their Significance, p. 50. Food Microbiology Fundamentals and Frontiers, 2nd ed. American Society for Microbiology Press, Washington, DC.

7. Arendt, Elke K., Liam A.M. Ryan, and Fabio Dal Bello. 2007. Impact of sourdough on the texture of bread. Food Microbiology 24:165-174.


This article was first published in Bread Lines, a publication of The Bread Bakers Guild of America.
Vol. 16, Issue 2, June 2008.

Related Links:
  The Pineapple Juice Solution, Part 1 | The Fresh Loaf
  Lactic Acid Fermentation in Sourdough | The Fresh Loaf 
  Basic Procedure for Making Sourdough Starter | Cooks Talk


mountaindog's picture

Thank you for such a throuroughly written article. I espe. found your comments useful about the 2 week mark at room temp being around when L. sanfranciscensis appears (or wakes up from dormancy in this case?). 

Like many others who have been following your informative threads here at TFL, I've started maintaining my starter at room temp. much longer then before (at least 3 days per week). When I do store it the other 4 days, I've been keeping it in a separate small frig that is set to around 50F. This seems to be making a difference in the activity and the flavor and smell (all positive). I wonder whether you think that is beneficial in the long run or not, or if it is still too cool. I'm sure it would be even better if kept at room temp all the time. If I can figure out a system and set of recipes to save and use the daily discard more, I may do that yet.

Debra Wink's picture
Debra Wink

I use different temperatures for different reasons in different situations. For culture preservation, I like to store my starter in the fridge. This is when I won't be feeding it and I just want to arrest its development as much as possible. I make sure the starter is healthy, active and vigorous first. Then I feed it and put it directly into the fridge. I don't let it sit out and grow for a time first, because I don't want it using up half its food supply right out of the starting gate---it could be in there a long time. That's for storage, or any time I just don't have time to fuss with it.

For maintenance, I ferment and refresh it at room temp---maybe once a day or three times a day, but I let it live its refreshment cycles on the counter to promote and balance the right organisms---only chilling it when I want to arrest it again. I avoid successive feedings at cold temps because that translates into multiple generations. The populations grow and multiply slowly, and at different related rates---some so slowly that they might be flushed out by successive feeding over time, and conditions may change so as to allow different species to dominate. Natural selection gets its impact through multiple generations. That's why, when I refrigerate, I don't feed until I can bring it back out and refresh for a few cycles at room temp again.

50F won't arrest the organisms as much as lower refrigerator temps, so it would not be my recommendation for storage, but it can be a useful temperature to use whenever you're trying to reduce the sour and create a milder starter, or just need to slow it down temporarily until you can get to it. Does that make sense? That said, I guess 4 days could be considered "temporary" if it is not warm enough for the starter to deplete itself in that time. I'm a big believer in trying different things to see first-hand what happens. And if you find that it works well, then there's your real answer :-)

foolishpoolish's picture

Great post! Your dedication and excellent write-up make for an enlightening read.

After my recent protease problems, I decided to ditch all my existing starters and start fresh so I have been through all the 'phases'recently. I'm pleased to say that from mixing up a crazy brew of 11 grain 'seed culture', I now have 5 healthy starters.

The deliberate acidification of a starter culture is something I try to avoid if at all possible - especially in the beginning stages. I figure it's better to give all the organisms a fighting chance and reach an equilibrium than to bias the result from the start. That said, I have been known to use cider vinegar to rescue a starter which has a continuing bout of the 'Leucs'. :)

Regarding the apparent delayed yeast growth (lactobacilli being the first to populate)...I wonder if perhaps the lactobacilli produce specific enzymes (maltose phosphorylase is one that I've seen mentioned) that are conducive to yeast growth. I've read that in a given culture there can often by symbiotic relationships between lactobacilli and yeast, each able to metabolize different sugars hence a peaceful coexistence rather than competition. Is it also possible that the lactobacilli 'win out' over certain bacteria which, if left unchecked would inhibit or directly compete with the yeast?

I've noted the changing aromas from my starter during it's daily feed cycle. Initially, the aromas are those I would associate with lactic acid production,sometimes followed by a sourer smell (acetic?) before finally the yeasty aromas (esters, alcohol) dominate. I suspect that starters go through a mini-version of the '4 phase' process each time they are fed. If that's the case, then the same must also apply to the mixing of bread dough - useful for monitoring progress of fermentation and perhaps taking advantage of this for specific flavour profiles in bread?



Debra Wink's picture
Debra Wink

I have been known to use cider vinegar to rescue a starter which has a continuing bout of the 'Leucs'.

Once you have yeast growing, you won't see the leucs again. They are transient and can't persist in a type I starter. FWIW, I don't recommend adding vinegar to sourdough starter, because it isn't good for yeast. And fostering yeast is really what this whole exercise is about, because without it, you don't have leavening.

I suspect that starters go through a mini-version of the '4 phase' process each time they are fed.

It's just the one time. Once yeast and sourdough LAB are established, they will keep marauders out. There is strength in numbers :-)

ehanner's picture


Thank you for your Part 1 and now Part 2 essay on sourdough culture populations. I must be turning into a total nerd on this subject since I seem to be absorbed by the content of your research.

After reading the above, I am now thinking that the ratio of old starter I keep to feed may be more important than I had realized. I have been using 50g starter, 75g water, 75g flour on a daily room temp schedule. That amounts to a 1:1.5:1.5 ratio. If I am interpreting you work correctly, I should be able to lower the pH some by using a 1:1:1 ratio. In effect tripling the amount every feeding. That would have the effect of limiting the food supply and causing a more thorough consumption of sugars and lower pH. Does that sound right to you? All other things being constant, starving the starter to some degree could create a stronger sour, if I am understanding you.


Debra Wink's picture
Debra Wink

Eric, in theory, yes. For one thing you are leaving more acid and lactobacilli in the mix from refreshment to refreshment (concentration-wise), and if the feeding schedule remains the same, you should see more acid accumulate. But, if at the same time you increase the feeding frequency, you can also acheive the opposite effect.

The danger in aiming for low pH in the maintenance of your starter, is that you run the risk of losing your L. sf, because it is more sensitive to low pH than the other lactobacilli. Also you could lose leavening power both in reduced numbers of yeast and reduced vigor. It's a delicate balance :-) You may or may not find it a better alternative to work at increasing the sour in your pre-ferments, rather than in your "stock culture."

That said, Pamela (xaipete) started feeding her starter 1:1:1 once a day, using a blend of 75% bread and 25% ww flours. I think maybe that's what Leader was intending, but can't be at all sure. Maybe she will chime in here and give us a report on how it is performing now. I know it increased the sour for her, but we didn't know how its leavening power would hold up over time.

xaipete's picture

Things are going along very well with my starters now. It took them about a week of daily feeding at a 1:1:1 ratio for them to *taste* sour--I never was able to detect a change in odor at that point. After that, I firmed them up at 1:3/4:/1/3 (flour to water to starter), let them double, and then put them in the refrigerator. (I have one WW starter and one White starter). It has been several or more weeks now and I've been using both starters and re-building them about every 4 to 5 days. I had also begun to notice that my WW starter was really smelling and tasting sour, more sour than my White one, which didn't smell sour at all. Last time I re-built them, I substituted a little of the WW starter for the White starter and that made the White starter a lot more sour tasting and now it is starting to smell sour too.

Regarding the 75% bread and 25% WW flours: I did do that when I was working with the 1:1:1 everyday feeding stage, but ceased that after I firmed them up and stored them in the fridge. Since I have both types, at this point it is easy enough to incorporate some of the WW starter in with the White when feeding.

So things are going very well (thanks mostly to Debbie's long-suffering advice). I'm continuing to work at making both WW and White Sourdough breads, and they are improving with each batch. Sourdough is a new venture for me so I'm still on a learning curve.


Susan's picture

It is most kind of you to share your knowledge.

Susan from San Diego

gavinc's picture

Thanks for sharing your wonderful research with this community.  I have read much over the years on the various theories of starter development but alas very little evidence based.  Thanks again.



Debra Wink's picture
Debra Wink

Susan and Gavin, thank you very much. It's nice to be in a community where I can talk about this stuff to my heart's content. Like Eric, I find it all fascinating, but unfortunately, it won't make me popular at dinner parties ;-)

davec's picture

Thank you, Debra.  As Gavin mentioned, there is a lot of information out there about sourdough cultures, but precious little of it is evidence based.  Now, we just need to find a baking enthusiast who still has lots of money, and would like to fund all the experiments you can devise.


dmsnyder's picture

I want to add my thanks to those already expressed. Nice work and a story well-told.

I see you have experienced what draws some of us to communities like TFL. Few have friends in their analogue relationships who would tolerate a discussion in depth of sourdough microbiology, not to mention get really excited about it.



Debra Wink's picture
Debra Wink

Thanks again, David and everyone. It's funny---when people ask me what I've been up to, they don't really want me to tell them. So I end up listening politely, while they blather on about how their kids are doing in school or sports, or career, or whatever phase of life they are currently in. But try to share your excitement over producing a perfect loaf, and no one understands just what a triumph it is. It's just bread. They all know that I bake, but my family and friends really have no clue that I have this whole other "secret life." Shhhh, don't tell ;-)

rainwater's picture

Without knowing any of this very helpful scientific explanation, I took Reinhart's formula on faith, and used "lemon juice".  I squeezed one lemon plus the remainder of liquid in water (I figured lemon is much more acidic than these other additions).  Then I proceeded according to the plan.  Two months later with my first's very strong and good......

I know I would have been discouraged if my first attempt at sourdough starter had, I'm an afficianado of sourdough bread......

Thank you......

Pain Partout's picture
Pain Partout

I am new to the TFL. but have become an avid reader at this site, partly because of your superb input.   Debra,..just wanted to say that you have done an excellent job of clarifying the microbiology involved in any "culture"..into a subject that NON-scientists can readily understand.  Not, an easy job.  Sourdough culture IS  science,...not Hokey Pokey.   All said,..this is a NON-exact outcome though,  given that we are left with many variables to contend with. It is biology, not chemistry.  Understanding microbiology certainy should enhance our ability to create good sourdough starters.    Sorry...for the looooong type.

Debra Wink's picture
Debra Wink

Exactly. It's that living element that makes it all so complex. Living things interact with each other and their environment in a dynamic way, rather than linear. And their biochemical reactions are controlled by feedback mechanisms. I often say "It's never that simple with living things." Maybe I will make that my tag line :-)

Mini Oven's picture
Mini Oven

Thank you Debra!  I am so thankful for your contribution.  The greatest part about it is that it all makes so much sense!  

...And inspirational!   And also the part about spores is facinating....

"...if given the proper stimulus they can return to active metabolism within minutes through the process of spore germination..."

Within  MINUTES!   Gosh wouldn't it be great to find out what those catalysts are?  Just put them concentrated into various dropper bottles and be able to pick out one or more favorite Lactic acid bacteria to encourage?  Sort of quick jump the evolutionary process? 

Then the initial recipe might be reduced to read:  Instant Sourdough >>  2 drops potion #9, 2 Tbs Pineapple juice, 2 Tbs whole flour!


Debra Wink's picture
Debra Wink

Yep, making sense of it all---that's my goal. When you understand the starter and what the signs mean, you can take your cues from it, and know what to do to get it to behave. Kind of like Cesar Millan with dogs; you can be a Starter Whisperer ;-)

And minutes, yes---activation is like flipping a switch from OFF to ON. As long as it is Off, nothing is going to happen. But once On, then they can germinate, start growing and utilizing sugars again. With yeast, that ON switch appears to be controlled by a pH thermostat. At least, that's what the evidence seems to point to.

Soundman's picture

Hi Debra, and thanks for these fantastic posts!

It's a grabber of a story. I wish all of TFL, especially Sourdough and Starters, could just point to your posts, because even here we create a lot of misinformation. (I should go back to all my old posts and edit out all the wrong stuff I have propagated on this subject.)

There's so much food for thought here, though I love that it distills down to a simple method, the only method I ever used and which worked like a charm. I think my biggest takeaway is the one-time-deal thing, which had never really occurred to me before. Then there's the wave of metabolic changes that you so aptly liken to a relay race! And I guess from time to time we get frustrated and mess up the attempts of the microbes to pass the baton!

I also agree with all your comments about temperature, hydration, and feeding cycles as things to experiment with, both for flavor and rising's sake, as well as for helping with scheduling in our complicated daily lives. (I particularly like to use temperature during the winter to modulate the process, as there are so many different temperature zones available in my house when it's cold outside.)

Many thanks. I have bookmarked your posts: Favorites. (I love your picture. ;-))



Soundman's picture

Hi Debra,

I've been meaning to ask this question for a while, and you're the person I would really like an answer from, if you have one, so pardon me for posing it here on your blog!

I am wondering why my sourdough bread increases in sourness even after I freeze it. (I like it, by the way, I'm just non-plussed.) I would have thought that freezing temperatures would just stop the metabolic action in its tracks. But no, the bread continues to get more sour for 2 or 3 days more even after freezing. Any idea why?



Debra Wink's picture
Debra Wink

David, good to see you again, and thank you :-)  The flavor changes are a bit beyond my scope, but I think this has more to do with chemical changes happening in the bread as it ages, rather than bio-chemical action of living organisms. All the sourdough critters are killed during the baking, but chemical and physical changes still occur which affect taste and texture. Maybe some of those changes enhance or magnify the tongue's ability to pick out the acid notes from among the other flavors. Any cereal chemists here who can shed some light?

Several years ago, a friend gave me a whole bunch of ripe peaches from a trip down south. To preserve them, I ended up mixing up several batches of pie filling, freezing in, and then popping them out of lined pie plates, and storing them as individual "pie-cicles," I call them. I also baked off a few pies right away, to adjust the sugar, spices and thickening. The fresh pies and the ones baked within a month or two after freezing all had a slight bitterness to them, that I would describe as a peach pit taste. But once they got past 3 months in the freezer, the bitterness disappeared, and the flavor kept improving with time. I wasn't the only one who noticed. I don't know if it was the freezing specifically that took away the bitterness, or just the slow aging with the other ingredients, and without threat of bacterial spoilage. But the veil of bitterness was lifted, and other flavors were enhanced.

I know that doesn't particularly answer your question, but it was evidence to me that some flavor changes happen or continue even in the freezer.

Soundman's picture

...just fine. (or ... until the real thing comes along?)

Hi Debra, and thanks for thinking about this and your memory of a related situation. Of course the critters who turned the flour and water into bread have long since shuffled off their part of this mortal coil by the time I am tasting my loaves.

I remember in BBA Reinhart, in the section on Poilane miches, tells the reader that Poilane himself prefers the bread after three days, though the author is not convinced. I am convinced that bread (and peach pie too, under the right circumstances) changes flavor over time. Of course many sourdough bakers have pointed out that you can't tell how sour your bread will be until at least the day after baking. I guess now we can simply extend the time over which flavors change, and as you said somewhere, remember that one culture's spoilage is another's flavor perfection!

Thanks as always,


crumb bum's picture
crumb bum


First off thanks for posting all this great info.  Lots of this goes right over my head but like Hammelmans book every time I reread it I get another tidbit or gem.  I was having trouble getting my breads sour.  I started a new starter thinking this was the cause until I read this paragraph.  "Just keep in mind that the first days of the seed culture process have nothing to do with developing flavor or even fostering the most desirable species. The object is simply to move through the succession and get the starter up and running. The fine-tuning begins there. Once yeast are growing well, choose the hydration, temperature and feeding routine that suits you, and the populations will shift in response to the flour and conditions that you set up for maintenance."   A light went on at this point when I realized my maintenence is making my starter "what" it is, not being old or tainted in some way.  It seems obvious but I need to be hit over the head multiple times before I get it.  I do have one question.

The starter goes through each phase laying the groundwork for the next phase.  Is it possible to get stuck in a phase and have a starter that appears healthy and alive?  I'm thinking of the stage that has bacteria that produce C02.  Would this stage raise bread but not give the flavor that is desireable, giving us a "false positive"?

Thanks again Great Post

  Da Crumb Bum


Debra Wink's picture
Debra Wink

Thanks again Crumb Bum :-)  It's nice to know that it makes sense. Yes, and how could the first few days be about flavor if you don't even have sourdough organisms growing yet. The gassy bacteria are only there for a day or two, and so timing is critical if they are to be employed as leavening. I think this would be classified as a type 0, or "spontaneous" sourdough---idli batter being an example. (I've never had idli, but I would assume that it has a very unique flavor.) But if you keep feeding, these naturally disappear, so idli batter has to be started anew each time.

When you keep feeding, it transforms into a type I sourdough, which is the kind most people here are aiming for. Type I sourdough is a mixed culture of LAB (mainly lactobacilli) and wild yeasts. The more consistant you are in maintenance, the more likely you are to have just one or two of each dominating. The more hap-hazard you are with temperature and feeding, the more likely it will be more of a mixed bag because their environment keeps changing, favoring (or not favoring) various LAB at differnt times.

We understand intellectually that the organisms came from the flour to begin with, but we sometimes forget that they are still there, ever present, and always being added back with each feeding of our cultures. They just aren't all growing. If we have lost a disireable fraction, or we want to foster a different LAB population, we need only to make the sourdough environment friendly to that organism. So changing your maintenance routine may be all it takes to bring about a change in the character of your starter. Temperature, hydration, feeding rate and schedule, flour---these are all things that we can manipulate to change that environment. The challenge is in figuring out what changes to make, and having the patience to give it time to take effect. But you can often fix an existing starter faster than you can make a new one and get it to where you want it.

I realized my maintenence is making my starter "what" it is, not being old or tainted in some way.

Exactly. And it also means that it doesn't matter who's formula you used to create it. It isn't a Silverton starter, or a BBA or Hamelman starter, or even a Debra Wink starter. It's a Crumb Bum starter :-)  All the different formulae are just different roads (some bumpier than others) to get you to the same place. From there you can go any number of directions by how you maintain the starter and manipulate the dough.

Judon's picture

Thanks Debra for your work and for taking the time to post it here.

Yours is the formula I started with over a year ago and have been happily baking and producing great breads since.

I can't even remember how I arrived at my maintenance schedule, refreshing amounts etc. but now I feel inspired (and confident) to branch out and experiment with my starter.

My husband's a former bakery owner and he's wild about your post also!!




Debra Wink's picture
Debra Wink

Judy, that's so kind of you to say :-)

crumb bum's picture
crumb bum

Hey Debra

Thank you for the detailed and quick answers to my questions.  I have just a few more questions and then I will leave you alone, probably, unless I come up with more questions.  You have ruined me,  I made and used a starter for years.  I did not care how it worked or why, it just worked.  Now I want to truely understand it in order to control it. 

My questions are about transfering the starter to a preferment and then a dough. You told EHanner that instead of going 1:1:1 with his stock starter he might want to tweak his preferment instead.  You cited Lsan. and yeast could be weakened in such a low ph environ.  My question is if all of the yeast and flavoring bacteria take a certain environment and time (sometimes days)  how is this transfered to the pre and later the dough.  Are we to assume that both the yeast and bacteria grow in the new dough that is usually a different hydration and left 12 to 24 hours at most?  Or is the starter just a concentrated  "flavoring" (bacteria)  that has leavening power (yeast) that does not grow a whole lot after it is introduced to its new environ?  If this is the case you could let a starter go until the yeast were weakened but flavor was at its max and then add fresh vigorous starter to the dough at the right time and end up with the best of both worlds?  I have not heard of people doing this though.  I assume people are looking for a balance somewere in the middle of these extremes.  I hope my questions make sense.  The short version is it seems like at each stage (pre and dough) your starter gets diluted by flour, water and time, and less and less of its characteristics that you work so long to build survive.

Last, we need to get Floyd to give you a corner of this site.  I like the Bill Nye Science Guy rhyme thing so how about Debra Wink Sourdough Shrink?  Seriously I think a science technical section would be very cool and you would have my vote for head honcho of said area.

Thanks again

Da Crumb Bum

Debra Wink's picture
Debra Wink

Crumb Bum, I'm sorry it has taken me so long to get back to you. I needed some time to mull it over. Sort of figure out the question behind the questions, because I think the answer starts with fundamentals that hopefully can clear up some of the confusion around sourdough.

You told EHanner that instead of going 1:1:1 with his stock starter he might want to tweak his preferment instead.  You cited Lsan. and yeast could be weakened in such a low ph environ.

Please allow me to clarify---what I said was that he might not want to aim for sourness in his starter, because low pH could have a negative effect on the population dynamics. The 1:1:1 ratio is not really the issue, because time and temperature are an equally important part of the equation. You can create sour, or mild with a 1:1:1, or just about any ratio, depending on how often you refresh and at what temperature.

is the starter just a concentrated  "flavoring" (bacteria)  that has leavening power (yeast) that does not grow a whole lot after it is introduced to its new environ?

Flavoring isn't the bacteria---it's what the bacteria produce. So you won't get flavoring from them if you don't have the bacteria. But they don't have to be multiplying to be metabolizing sugars and producing flavor compounds. They just need to be present in sufficient number.

it seems like at each stage (pre and dough) your starter gets diluted by flour, water and time

Initially each stage may be diluted by flour and water, but time allows it to rebuild again.

if all of the yeast and flavoring bacteria take a certain environment and time (sometimes days)  how is this transfered to the pre and later the dough.  Are we to assume that both the yeast and bacteria grow in the new dough that is usually a different hydration and left 12 to 24 hours at most?

To get a broader understanding, let's step back and look at the different stages in terms of the bigger picture. That may help to put it in perspective. In my view, there are three stages to sourdough---the stock culture, the pre-ferment(s), and the final dough:

The stock culture (starter, chef, mother, seed, storage leaven---whatever you choose to call it) is for preserving, maintaining and propagating the organisms that give your breads their desired flavoring and leavening. While they produce substances as metabolic by-products that we consider flavorful, exploiting that is not the primary goal at this point. The object here is to keep desireable organisms alive, healthy, and in sufficient numbers to do what we call on them to do for our breads. So the goal should be to cultivate the right kind of environment to foster the desired organism profile. What is best for the organisms isn't always the same thing as what is best for dough. That's an important distinction.

The pre-ferment(s) (first build, second build, etc., levain, starter, sponge, pre-dough...) have two jobs. One is to continue to build a healthy population of organisms with enough collective power to raise and flavor the dough. The other is to start building flavor before the dough is mixed. Using a pre-ferment allows for more variation in the use of hydration, time and temperature as flavor building tools. It also serves to shorten the dough fermentations later, and allow more scheduling flexibility, because part of the flour is already fermented.

The final dough is really the last build or feeding of the sourdough, if you will. At this point, you inoculate the dough with the active cultures that you have cultivated, and infuse the fresh flour with flavor already developed in the pre-ferments. The hydration may be higher or lower, depending on the type of preferment, but there is also an addition of salt. Salt slows organisms, LAB more so than yeast. So do reduced hydration and retarding. Fermentation may be shorter, or slower at this point, depending on the temperature, so all these factors add up to create an environment where reproduction is limited. But whether they multiply or not, they continue consuming sugars and producing effects in the dough. At this point, the organisms are headed for the oven, so it's the end of the line for them, making leavening and final flavor development their main function.

Do you see how the objective shifts from propagation, to flavor and lift as the process proceeds toward completion? Again, what is best for the bread is not necessarily the same thing as what's best for the microorganisms. The fundamental difference that sets the stock culture apart from the other stages is "continuous refreshment." It's the continuous nature that allows natural selection to determine the evolution of the starter. The pre-ferment to dough stages are a relatively short dead-end spur off the continuous loop. The organisms are more fixed, because there won't be enough generations to lose them through natural selection. So we have a temporary opportunity to manipulate them into producing the effects we desire, even if it isn't ideal for them.

If this is the case you could let a starter go until the yeast were weakened but flavor was at its max and then add fresh vigorous starter to the dough at the right time and end up with the best of both worlds?  I have not heard of people doing this though.

This is a relatively common practice, but by adding bakers' yeast and fresh flour rather than more starter. I'm not sure how much of the flour you can pre-ferment and still produce good bread. Maybe someone else can comment on that, but I think the notion of "maximum flavor" is problematic. What do you mean by that? The sweet nuttiness unlocked from the flour, or do you mean as sour as you can get it? Not all flavors (and rheological effects) produced by very long fermentation are necessarily good ones. And there's more to flavor than lactic and acetic acids, so maybe it's best to think more in terms of balance and appropriateness. That again, gets back to the type of bread and personal preference.

You have ruined me

Nah. Just think of this as the kind of mental exercise that will keep your brain young. It has to be better than crossword puzzles ;-)

crumb bum's picture
crumb bum

Hey Debra

Thank You for taking the time and effort to not only answer but to really explain the hows and whys.  This is really fascinating stuff.  I may have a few more questions in the future but I will try to leave you be so you can bake some bread.

Thinking of the Stock culture as a place to make all the organisms happy and healthy so they can produce all of those wonderful flavor compounds is a new way for me to think about it.  I always thought I needed to get my starter how I wanted it, and try to transfer that to the final dough.  I probably have done my culture and therefore my final dough disservice by doing this. 

I think you also make a case for keeping just one starter.  It would seem to me that if it is healthy it would not really matter if it was kept at 100% or 60%, the organisms we want would be there and would do their thing in the preferment.  Or would certain organisms not be present in starters of different hydrations therefore not be around to produce certain flavors?  You can see my promise of no more Questions lasted exactly 3 paragraphs.

The x factor in all this that you also keep mentioning is time and temp.  I think this is the area I will focus on because I know I have a healthy starter.  I will try to post some of my results and keep you up on my meglamaniac like quest to control my yeast (once it hits the preferment).

I think if I were to have the ability to control all of "this wild yeast stuff"  and turn out cookie cutter bread everytime I would get bored with it.  The fact I cant control all of it, just some of it,  and there is all of this "life and death struggle, natural selection, etc"  going on in a mix of flour and water keeps my head in the game.  I have baked for quite a few years now and I am more excited now than I was when I first started this whole process.  A big part of my renewed interest are your postings,  The 2 pineapple articles and the one before that explaining the whole thing.  This stuff is gold.

Thank You Again, Da Crumb Bum

Debra Wink's picture
Debra Wink

And thank you for the compliment. It seems I forgot to come back here and answer this. Forgive me, I've had taxes on my agenda. Can't wait until they are done for another year.

I think you also make a case for keeping just one starter.  It would seem to me that if it is healthy it would not really matter if it was kept at 100% or 60%, the organisms we want would be there and would do their thing in the preferment.  Or would certain organisms not be present in starters of different hydrations therefore not be around to produce certain flavors?

This has more of an effect on the relative numbers of LAB in proportion to yeast. Hydration is one of those things that influences relative growth rates. Lower hydration slows LAB more than yeast, so if you like milder breads and want to control LAB growth, try keeping your starter firm. If you like more sour, then let them go to town by keeping your starter 100% or more. I think Hamelman's liquid starter in Bread is 120%. Try it both ways and see which you prefer.

intergalactickungfuoverdrive's picture

Hopefully i’m not replying to early; i am maybe 2/3, 3/4 through part ones posts on the 1st page; and at this comment here to Crumb Bum, 3/5 down the page, on the 1st page of part 2


i have tried experimenting with this before and now have started a blog here on my current progress. i am now at a point where i think i should juggle around my current jars to make starter; and use some for longer term pre-ferment (but fed enough, to stave off mold);

the flavor compounds i am looking for are the cheese cultures products from aging (and? with leconostocc mesenteroides var cremoris, initial flavor (if it isn’t decomposed later ??))

i am curious how cheese aging works; with the bacteria staying alive and making what they do; but also, i dont know the pH ranges they are non dormant in.

i believe there are 12 intended bacteria types in my one jar (because i have 2 identical mesophilic mixes but two companies/cell lines) 2 in the thermophile, 4 x 2 (the repeats from briena and flora danica/hansen) in each mesophile, 1 propionibacterium shermanii (the really important goal for me here; being vegan and shooting for healthy propianates that even prevent cancer; and which taste delicious) , and a staphylococcus xylosus II strain in a choozit brand MSA adjunct culture

my plain jane san franscisco sourdough culture attempt got moldy, but the one i added thermophile to, with swiss cheese bacto (prop shermanii) , had a dollop of it added to it before it went moldy 

(i have ordered another san francisco sourdough culture as a backup)


see, i also want to experiment with keeping a special ale yeast strain (i targeted for one that produces diacetyl and can withstand higher fermentation temperatures without tasting bad) which i am hoping could work out;

it is an english strain ((wyeast london ESB 1968 ale)), which are known to produce diacetyl (not only do i want to make a real deal, slightly sweet butterbeer like in harry potter, but, i’m hoping to make butter-with-cheesy-bread :) )

for a buttery cheesy bread, all from little beasties and flour/water


i was wondering if i could make my own sourdough with the wyeast (which is reportedly a bit rapid in beer fermentation; so, being that ale yeasts are generally less active then active  dry yeasts and need longer rise times; compounded with sourdough rising slower; it figured good to find a rapid-ish fermenter, with a high temp limit, and produce diacetyl if not too high on that temp limit) and cheese yeasts, swiss, specifically, which needs a helveticus culture (or anything else ?) for some amino acid or protien feed.

i just updated my blog posting and after reading some, last minute, am thinking i should maybe underfees both remaining jars with maybe 1 Tbl flour and water, and stir nice (?) just to keep it firsty against mold, but not dilute pH

(the mesophilic one, with the leconostocc mesenteroides var/ssp? cremoris, smells food and cheesy :) i can correct spelling later, i hope. both have bubbles, i believe.

Wild-Yeast's picture


I thank you for filling in a great many of the blank spaces concerning the behaviour of the sourdough starter metabolism.  Also, I congratulate you on snapping together so many of the missing blocks in a manner that can be well understood by a wide audience (this, by itself, is no small feat).

Your mention of wild yeast spore development was, for me, a most important missing element.  For some reason I had always assumed the yeast cells were somehow magically "there and ready to go" through asexual reproduction.  What is fascinating is the sporing mechanism and its ability to "lie in wait" for the right conditions.  The fact that haploid spores mate (reconjugate) in sexual reproduction suggests that a new wild-yeast organism might, in fact, evolve each time a "from the beginning" starter is made.  I am left wondering whether this results in a higher degree of diversity for the wild-yeast or whether the chromosones are relativley "guard banded" against this?


Debra Wink's picture
Debra Wink

I had always assumed the yeast cells were somehow magically "there and ready to go"

I think we all did---'cause that's what cookbooks tell us.

My contact at Lallemand told me, "spores are not the only dormant form." He didn't elaborate, but he also didn't know in what form they are present in flour---spores (haploid), or some other diploid dormant form. I suspect spores, but I also don't know what prompts yeast to sporulate in the wild. I have gotten away from calling them spores, because technically speaking, I just don't know. Either way, they are desiccated and dormant. Non-sporing organisms also have the ability to go dormant, which allows them to survive in nature. The mechanisms of dormancy still aren't all that well understood.

Spore-forming bacteria such as Bacillus and Clostridium, form spores differently than yeast. they're not haploid, or part of a sexual reproductive cycle. The quote I pulled encompasses all spores in a general way, but it was because low pH is sited as a common activator that it caught my attention. That's the one thing that was consistant with the appearance of yeast in my studies. Whether it took 3 days or 3 weeks for the pH to drop, that's when yeast started to grow. And the one time I acidified the day one mix to 3.5 with citric acid, I had yeast growing on day 2.

There must be some genetic diversity in yeast, otherwise there wouldn't be so many different strains within each species. Coincidentally, someone on the BBGA email group referenced an article just this morning on genetic diversity in Saccharomyces cerevisiae which ties in nicely with your comments. I don't have access to the whole article, but the abstract provides a nice summary. Given your screen name, I thought you might enjoy it :-)

Bread, beer and wine: Saccharomyces cerevisiae diversity reflects human history


Fermented beverages and foods have played a significant role in most societies worldwide for millennia. To better understand how the yeast species Saccharomyces cerevisiae, the main fermenting agent, evolved along this historical and expansion process, we analysed the genetic diversity among 651 strains from 56 different geographical origins, worldwide. Their genotyping at 12 microsatellite loci revealed 575 distinct genotypes organized in subgroups of yeast types, i.e. bread, beer, wine, sake. Some of these groups presented unexpected relatedness: Bread strains displayed a combination of alleles intermediate between beer and wine strains, and strains used for rice wine and sake were most closely related to beer and bread strains. However, up to 28% of genetic diversity between these technological groups was associated with geographical differences which suggests local domestications. Focusing on wine yeasts, a group of Lebanese strains were basal in an FST tree, suggesting a Mesopotamia-based origin of most wine strains. In Europe, migration of wine strains occurred through the Danube Valley, and around the Mediterranean Sea. An approximate Bayesian computation approach suggested a postglacial divergence (most probable period 10 000-12 000 bp). As our results suggest intimate association between man and wine yeast across centuries, we hypothesize that yeast followed man and vine migrations as a commensal member of grapevine flora.

nicodvb's picture

Hi Debra,

I'm very interested in what you wrote about the appearence of LAB Sanfrancincensis: that generally it appears after 2 weeks of daily refreshments at room temperature.

Can I exchange the word "day" with "refreshment"? I mean, if I refresh twice a day at room temperature can I expect  that that LAB strain will appear sooner, after 6-7 days? Is it a matter of generations or does it take a longer time?


I'm testing the apple cider on a rye starter, but in the last days I made a white wheat starter with 3 gr of white vinegar dissolved in 47 gr of water and mixed with 50 gr of WW flour. The PH read was 4.6. After 2 days the starter rose and now it seems to be *very* vigorous. When the starter collapses the PH generally drops to 3.8. I hope it's not too low.

Debra Wink's picture
Debra Wink

Nico, that's a very good question, but I'm afraid I don't really know the answer. I think one reason it won't show up in the beginning is because the pH gets fairly low before the wild yeast will start growing. Too low for L.sf., which doesn't grow at all below pH 3.8. Once the yeast start to grow, and refreshment rate and frequency increase, the pH gradually rises back up, and the conditions become more suitable for growth of Lactobacillus sanfranciscensis. But not knowing exactly where they come from or what they need to become active, I'd only be speculating that you can hurry them along. I find it interesting that in the procedural notes of research papers, the growth media used is complex and always contains yeast extract in the mix. Maybe L.sf. needs something that the yeast produce. Or, maybe they just have a 2-week lag phase. I wish I knew. I would certainly recommend feeding your starter twice a day :-)

Here is a graph showing the effect of pH on growth of two strains of Lactobacillus sanfranciscensis and one Candida humilis (formerly known as C. milleri). This is from Modeling of Growth of Lactobacillus sanfranciscensis and Candida milleri in Response to Process Parameters of Sourdough Fermentation (1998), by Ganzle, Ehmann and Hammes:

FIG. 2.  Effect of pH on L. sanfranciscensis LTH2581 (open circle ) and LTH1729 (triangle ) and C. milleri LTH H198 (square ) (A) and effect of NaCl addition expressed as ionic strength on the growth of L. sanfranciscensis LTH2581 and C. milleri LTH H198 (B). The lines represent the predicted growth rates. Error bars indicate the standard deviations from the means of three independent experiments. The shaded areas represent the ranges commonly encountered during sourdough fermentations.


P.S.  I've noticed a lot of people using 'LAB' when what they really mean is Lactobacillus or lactobacilli. LAB stands for Lactic Acid Bacteria, which is a large group of bacteria that all produce lactic acid while fermenting sugars. The lactobacilli certainly fall under that heading, but so do many other genera, including Leuconostoc, Weissella, Pediococcus, and many others that are commonly found in sourdoughs and other fermented or spoiled foods. The abbreviation for Lactobacillus is simply L. or Lb. Hope that clears up the confusion :-)

Walden Pond's picture
Walden Pond

As a scientist and amateur baker, I really appreciated your posting. Thank you!

Debra Wink's picture
Debra Wink

and thank you too. Welcom to TFL :-)

hutchndi's picture


I am curious if you realise how your interesting and well written article is affecting the mindset of some of the sourdough community. Apparently there are some home bakers out there that are now under the impression that this is more than an observation of what naturally occurs in a new culture medium and how one may alter it while eventually reaching the same desired result, but they have somehow elevated your method to a now neccessary step in creating a sourdough starter. Once again the power of the internet is imeasurable.

By the way, I understand that you recently had the opportunity to bake with Mr. Hamelman, and I was wondering if he had commented on your pineapple juice method.

Debra Wink's picture
Debra Wink

Every once in awhile, I google to see what people are saying, and have come across a lot of misinformation and misunderstanding out there about it. That is one of the reasons I wrote the article. Unfortunately, I can't help people's misinterpretation of it. You'll never hear me say that pineapple juice is necessary in creating a starter---only patience.

But without the internet, the pineapple juice fix would never have been conceived in the first place, and I would not have been able to do the research or have the benefit of feedback, or even to be here on TFL today. So, I guess I can live with the downside. And I do believe there are a lot more proud sourdough parents as a result.

I did talk with Jeffrey about a lot of different things in the all-too-brief spare moments. Although I was there to take advantage of what he had to teach, pineapple juice did come up once. He asked about its purpose, and I gave a brief explanation. That was it; we had dough to divide and shape :-)


hutchndi's picture

I don't know if I would call it a down side at all, your article explains itself very well on it's own, and I don't understand why it can be so misunderstood. If anything, it is probably proof that your method has worked incredibly well for these people. As for the power of the internet, without it, I probably would never have gotten into sourdough bread baking in the first place (gasp).

Hey, if your method keeps people from tossing out innocent and potentially good starter, then that makes you the sourdough angel of mercy!

Debra Wink's picture
Debra Wink

I really didn't mean to come across so negative. If it weren't for the internet, I don't believe I would have gotten interested in sourdough either (double gasp). I tried sourdough bread in the early 70's as a young teen traveling through San Francisco, and I thought it was the worst bread I'd ever tasted. Now, I know it doesn't have to be that way. And it's been a wonderful journey :-)

now raising my glass of pineapple juice... Here's to the internet!

hutchndi's picture

That is kind of deja vu-ish, because someone sent me some sourdough culture from San Fran one time and after using it I didn't like it either, I remember the resulting bread had a not very appealing sort of cheezy taste to it, and I couldnt imagine what the big attraction of genuine "SAN FRANSISCO" sourdough bread was. That was so long ago now that I cant remember what I did with that culture, but I don't miss it.

tempe's picture

Hi Debra,

 I am new here and wanted to say thanks so much for your articles. I especially like your pineapple juice solution posts.  I don't have any books to refer to so the internet is it for now. My first starter just up and went mouldy in the fridge, so I tossed that out and after a little surfing I found your very interesting and thorough articles, just fantastic.  With all that new information I felt encouraged to have another go and seven days later  my starter is doing fabulously. My family think I've become a little obsessive about the whole thing, you know how it goes, 'I need to give Walter a stir' or 'Walter needs feeding'.  But Walter is doing great :) 

Debra Wink's picture
Debra Wink

So sorry I missed this a while back; I've been on a break of sorts this summer.

Welcome to sourdough :-)

tempe's picture

No worries, thanks for your reply and warm welcome. I hope you had a good summer break.  My starter is still going great , easily doubling and tripling when fed.  I have managed to bake a few boules, today's bake is the best so far, not as dense as others have been. Regards, Tempe

coffeetester's picture

So I am on day 5. My starter was not growing much but the smell was getting better. The temp in my storage area has been around 70 so today I decided to try an experiment. I put a pyrex pitcher in the oven twice and the temp rose to about 80. After 4 hours my starter has doubled. Here is my delema:

1. Should I feed it again tonight before bed since it has doubled. If I dont feed should I just stir it.

2. Does the temp from 70 to 80 matter. I might need to look for a different location then the oven since with the llight on it gets to 100 degrees with 2 lights. (On a side note I want to take 1 of the lights out of the bottom oven and see if it sits at 80)


Since this is my first really advancement with either of the 2 starters I have (The first smells good but wont rise) I dont want to make a mistake and undo 10 days of work.

Hopping to hear an answer tonight


Debra Wink's picture
Debra Wink

Mike, it's good to hear your starter has taken off. I'm sorry, I didn't see this last night, but you're okay either way. You could have fed it, but if you didn't, it will still be fine. The warmer temperature certainly could have made it rise faster, but at day 5, it may have just been ready regardless of the temp. Anything over 85ºF continuously, is not good for the wild yeast, and may cost you leavening power in the long run. But 70º is fine, and the yeast will still do quite well. So room temperature is preferable to uncontrolled heat now that your starter is expanding.

You can feed it more frequently now. Let it show you what it needs. Allow it to rise as high as it will (without stirring), and feed before it collapses too much. Two or three times a day is best. You can increase the refreshment (or decrease the ripe starter) until you find a feeding rate that works with your schedule.

Once you're sure you have a viable starter, there isn't any need to keep both unless you just want to. If it hasn't started rising after 10 days, I'm guessing the first one is either on a diet of only white flour at this point, or is getting fed too much or too often. It will work eventually, but no telling how long it will take. In my experience, usually 14+ days, but you can help things along by switching to whole wheat or whole rye until it starts expanding.

How do they look today?


coffeetester's picture

The Pineapple one looked like it double again after a vigorous stir last night deflated it. I was doing some reading and I am not sure of the direction I should be going.

Should I be using a 1:1:1 or a 2:1:1 feeding ratio. One of the things I want to learn from this is what ratio should I be using now that it is doubling. Is there a reason one works better or worse then the other. My understanding is the 1:1:1 provides more food for the starter so it should be more frothy and more then double.

The other question is that I start with 1/4 of a cup of room temperature water and then measure out the same weight in flour. I then either measure out the same weight in starter (Or double) and wash out my container.  Most of the videos done seem to do that but how do I get rid of all the excess starter in the container?


Thanks for any feedback


Debra Wink's picture
Debra Wink

"One of the things I want to learn from this is what ratio should I be using now that it is doubling. Is there a reason one works better or worse then the other."

Now that your starter is expanding, you're finished with creating the seed culture, and now you're moving on to maintaining it which is a different strategy. There are times when a 2:1:1 ratio (2x dilution factor) can benefit, but for the most part, 1:1:1 (3x) is the minimum, and 1:2:2 (5x) or more may be even better. It depends on how your starter is performing, and when the next feeding will be. How often can/will you feed it, realistically?

Let it show you what it needs. Allow it to rise as high as it will (without stirring), and feed before it collapses too much. Two or three times a day is best. You can increase the refreshment (or decrease the ripe starter) until you find a feeding rate that works with your schedule.

What I mean by this is that it's best to take your cues from the starter. Start with 1:1:1, and if/when it peaks and falls before it's time to feed again, either feed it sooner, or move to a 1:2:2 ratio. If/when that starts to peak and fall before the next feed, you can increase to 1:3:3 and so on until you find the right ratio for your feeding schedule. It's likely that you'll find when you keep it active this way, it will get more robust (rise higher, faster), and more fragrant, especially over the next two weeks or so. That's about how long it will take to fully transition and find its equilibrium.

Where you will eventually settle in, will depend on the room temperature, your culture, and how often you feed it---not necessarily the same routine as someone else. For mine, I like 1:1:1 every 8 hours. If I'm trying to flush out acidity and maximize leavening power, I may feed 2:1:1 every four hours or so (if I can) for a day. On the days I can only make two feedings, I'll do a larger refreshment. Smaller feeds more frequently will produce a milder starter (the way I like it). Larger feeds less frequently help build more potential for sour. But, it's important to keep leavening strong either way, which is why it's best not to let it collapse too much. The starter will give you signs, and this will all make more sense as you interact with it.

Hope that helps. I know the more you read, the more confusing it can get. There is no one right way, so don't worry about getting it wrong. This is one of those things you learn best by doing. Note that the above ratios are all 100% hydration, which is what your starter is currently. And that's probably best for now, because the math is more straightforward.

My best,

"how do I get rid of all the excess starter in the container?"

I'm not sure exactly what you're asking---how to get it out of the container? Or how to dispose of the unused portion?

One final suggestion is that since you will be going through a lot of flour at your present rate, you may want to cut all amounts by half.

RobynNZ's picture

Hi Debra

When I first started out and followed your PJ instructions, moving on and understanding starter maintenance was very puzzling for me, I couldn't find anything on this site that gave me an overview of maintenance. Now my starter has been going for more than a year and has made a wide range of delicious bread. I have learned what feeding schedule suits my conditions (adjusting it through 4 seasons in a home without central heating/cooling) and my baking schedule etc. Of course I now understand why there is such a myriad of maintenance methods used by TFLers, with all the variables each of our starters are subject to. Nevertheless I wish this post had been available to me back then.:) :)!!

So many newcomers are advised to read PJ-1 & PJ-2, so I wonder if you would be willing to cut and paste a copy of the main portion of this valuable post as an edit to the OP on this thread. 

Thank you so much for conveying reliable information to us in a manner that is easy to understand.

Regards, Robyn