The Fresh Loaf

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Confused on using starter at 12 hrs or 24 hrs old? (Tartine / Forkish)

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Bread Head's picture
Bread Head

Confused on using starter at 12 hrs or 24 hrs old? (Tartine / Forkish)

I have a Tartine starter and thought that you HAD to use the starter no more than 12 hour old??

I tried making some leaven bread using the Ken Forkish method and used my starter after it is 24 hours old (according to his recipe) and it works great.  The loaves turn out very nice.


What is the difference between using your starter at 12 hours old or 24 hours old? And I read and thought that the yeasts would be long dead if I waited that long to use the starter but I am getting great bread.  How so and where did I get confused?

Thanks for your time!


FlourChild's picture

Whether the starter is 12 or 24 hours old is only a matter of flavor and choice.  Forkish definitely has some sourdoughs where he uses the starter half way through a 24 hour feed, which is similar to the Tartine method.  Hammelman chooses to use his starters at maturity, which is simpler and produces a bit more acid in the final bread.  

It's important, though, to distinguish between starter maintenance and starter that's going into bread.  When making bread, you can take the starter at any point in the cycle that fits your flavor choices- for instance, half way through a feed cycle, 3/4 of the way, fully mature, etc.  For maintaining your ongoing culture, though, you always need to let it ferment until it's fully mature so that it has enough acid to stay healthy and ward off intruders.  

Bread Head's picture
Bread Head

I see it has to do with flavor.

Couple of questions;

What do you consider a mature starter, 24 hours from the last feeding?

What if I don't let my starter go 24 hours before each feeding......what if I feed it every 12 hours and it never rises and falls fully.  Are you saying that the acid wont build up and what will happen then?

Thanks for your help!



FlourChild's picture

I consider a mature starter one that has risen to its peak and then continued to ferment for another hour or two.  Watch the starter, not the clock.  At a cool temperature or with a larger feed, this will take longer.  At warmer temps or with a smaller feed, this will happen in a much shorter lenght of time.

The danger of not letting the culture reach full maturity is that the acidity is too low, which makes the culture vulnerable to infection from unwanted microbes.  

dabrownman's picture

but will do so here too since it fits.  Sour is really science but it doesn't have to be complicated.

Yeast live 7-8 days, not sure about labs, but i'm sure they have similar life spans from my experimenting .  I routinely build levains from small amounts of seed over (3) 4 hour builds where the levain is at full strength and doubles in 4 hours after the 3rd feeding.   But, a half hour after feeding the 3rd stage, I usually refrigerate the levain for 1 to 4 days. I also try not to use the seed until it has been refrigerated for 2-3 days after building it to peak as well.

Since labs reproduce 3 times faster than yeast does at low temperatures, even though they both slow down dramatically,  by retarding seed and levains you end up inoculating you bread with many more labs than yeast by retarding than you would if you built a 12 hour levain at room temperature and used it.   Bulk fermenting and then retarding inoculated dough does the same thing.  In the cold,  roughly speaking in 36 hours, you have as many labs in the dough  as you get at room temperature in an hour.  But the yeast increase is what you would have in 3 hours at room temperature.

The same thing is true at 85 F.Labs reproduce 3 times faster than yeast does but both reproduce much faster than at 72 degree room temperature.  At room temperature, labs and yeast reproduce at about the same rate.  So if you want sour you want to retard seeds, levains and dough for as long as possible while not allowing the dough, seed or levains to run out of food for the yeast and labs to eat or go past the 7 - 8 day limit yeast can live.

It seems the The Tartine and Forkish methods of levain building, among others, are developed to reduce the amount of sour in SD bread.not enhance it, which makes sense as SFSD is a very mild sour.   Your seed,levain and dough methods can be modified dramatically with time and temperature to increase or reduce sour depending on your personal taste or time limits.  White starters also produce less sour.  If you want less sour, use a a white stater and do everything at room temperature.  The yeast will multiply at the same rate as labs, the dough will be ready to bake faster and the sour will be muted.

Happy baking

BurntMyFingers's picture

Dabrownman, is that your word for microbes? Or...?

I'mTheMami's picture

Perhaps lacto bicillus ? (Spelling?)


that was my assumption, but we all know how bad making assumprions are....

dabrownman's picture

but it is short for Lactobacillus. Ganzel's work on the reproductive rates of Yeast and Labs, now many years old but very good and informative, points out how temperature effects both at the same time since they are symbiotic.  The idea is to slow yeast reproduction down while relatively enhancing  Lab reproduction at the same temperature and to extend the time as long as possible at that temperature before the bread is proofed and must be baked.

At 85 F Labs reproduce at 3 times the rate of yeast but both are reproducing very fast so in a very short time the bread is proofed and must be baked.  So high final proof of 1 hour gives you more Labs than yeast so more sour results  than you would get a room temperature where labs and yeast reproduce at roughly the same rate but it takes 2 hours to proof.

At 36 F Labs reproduce at 3 times the rate but very slowly - just not as slow as yeast does at that temperature.  So if you can keep the culture at this low temperature as long as possible then you will have way more labs than yeast in the population and the ability to create sour much faster than CO2 - when the temperature rises to 85 F for final proof.

It you want sour, this is the reasoning behind long cold retards of seed, levains and dough with a high temperature final proof.  There is now some data out there that points to the fact that labs may supply as much as half the CO2 to make the dough rise as well.  Even If this is true, it doesn't make any difference to the amount of sour production. 

The 2 other things that effect lab and yeast reproduction are what food they eat and at what hydration they are maintained.  Whole grains seem to favor Labs and high hydration favor yeast.    So maintaining 100% whole grain starters and levains at 60% hydration in the fridge should also produce more sour too. 

The most sour bread I have managed was starting with 1 g of 60% whole rye starter that had been retarded for 1 day.  It was fed 25 g of whole grain flour and water and allowed to sit on the counter at 85 F for 1 hour before being retarded for 24 hours.  It was then allowed to double at 85 F and was then fed 50 g of whole grain flour and 25 g of water and allowed to sit on the counter for 1 hour before being retarded for 24 hours.   When removed from the fridge it was allowed to double at 85 F before being fed 75 g of whole grain flour and 50 g of water and allowed to sit on the counter for 1 hour before being refrigerated again for 24 hours.   After letting it double on the counter at 85 F it was finally ready to make bread.  At this point we had a 66% hydration whole grain levain that was 251 grams.

We made a 50% whole grain bread out of half of it that had 1,250 g of flour and water in it at 78% hydration by adding diastatic and non diastalic malt, retarding it for 40 hours with a 1 hour bulk counter 85 F ferment after 10 minutes of slap and folds to develop the gluten and a similar 1hour final proof at 85 F after coming out of the fridge.

This bread was very sour and some would not like it like my wife and daughter.  My apprentice and I liked it fine and made it again with slight revisions.   It was a fun experiment to prove the theory but a normal levain build with one retard, an 18 hour dough retard and an 85 F final proof will make most breads plenty sour enough.  



BurntMyFingers's picture

I've been trying various combinations of warm and cold, long and short levain builds to get a really sour dough and this is a great refresher course. Interesting you say dabrownman that SF sourdough and the Tartine loaf aren't particularly sour. The Tartine recipe in their book doesn't make a sour loaf but the bread you buy at the bakery is distinctly sour. Similarly, I got a wonderfully tart Acme baguette last month and that set me on a new round of experimentation which I'l report on if I ever get something I really like. Otis

dabrownman's picture

remotely sour using Tatine or Forkish.   The bread you buy at the bakery I'm guessing is made using 24 hour 'old dough' for the leaven that was built for sour in the first place.  I did a round of old dough experiments not long ago and found the sour to be on par with SFSD which still isn't very sour on the sour bread scale :-)

leftypg's picture


You have motivated me to try getting things a little more sour!  I have two questions which I hope you can help me with:

1. With the higher temperatures and the long retarding time, in combination, there must come a point at which the pH becomes toxic to both of our little friends----How do you prevent this from happening, and is there a method you use to figure out where your dough is located on the pH scale?

2.  I have read that high final proofing temperatures result in less oven spring.  Has this been your experience, or have I misunderstood what I read?

Thanks for the enlightening posts,    


dabrownman's picture

tolerant to a lower pH than yeast is.  I suppose you could reach a point where the yeast might be killed off but I haven't ever had that happen or come close to that - even when retarding for over 40 hours.  If I am going to do a really long retard, I worry more about exhausting the food supply.  I try to add in some white diastaic malt so that there are more enzymes breaking the bonds in the proteins, carbs and starch so the beasts have more to eat and don't run out of food.  But at low temps there isn'tall that much feasting going on anyway.   It is all relative on the temperature side too.

At low temps labs are reproducing 3 times faster than yeast which means more sour but they are really slow too.  In 36 hours they will have made the same number as they would at room temperature in an hour.  At high temperatures they are reproducing 3 times faster than yeast and 3 times faster and at room temperature too.  So even a 36 hour retard at 36 F is only like proofing 1 hour on the counter you just get way more labs than yeast.

I haven't heard that a high temperature final proof effects oven spring negatively.  But, since I inoculate the dough with as many labs as possible and as few yeast as possible,  a 1 hour final proof at 86 F is like a 3 hour proof for labs at room temperature.   But, the few relative amount of yeast are inhibited at that temperature so it is like a 1 hour proof at room temperature.  What kills oven spring is mainly over proofing the dough almost every time and to a much lesser extent poor gluten development, poor shaping,  too low a baking temperature and not enough steam. 

I have no idea where my dough is on th pH scale but I would assume it is pretty low since i do just about everything possible to get i can to get it low.

There is some data out there that points to the possibility that labs can actually supply half the gas in the proofing process.  If this is true then you really have to watch the dough closely at final proof at high temperature because it can over proof very fast - and I do because a high temperature final proof after a long retard is less than hour sometimes.





ndechenne's picture

This is great struff, thanks. So let me ask you then, what's the basis for increased sourness production... more in the yeast, the labs (i.e. ratio to one another) or is it a combination of both over time? Lots of little questions i guess...

dabrownman's picture

makes the sour in SD and yeast supplies the CO2 gas to make the dough rise.  In a SD culture, the Labs and yeast live in symbiosis.  So if you can increase the rate at which Labs reproduce while holding back the rate of yeast reproduction you will have a more sour tasting bread as a result.  The higher the lab to yeast ratio the better id you want sour.  At 36 F the ration is 3 meaning that labs are reproducing at 3 times the rat of yeast.  At room temperature 68-72 the ratio is 1 meaning the reproductive rates of both are the same and at 86 F  the ratio is again 3 favoring lab reproduction at 3 times the rate of yeast.  

More recent science points to the idea that labs also provide half the Co2 gas to make bread rise.   But no matter. 

The other two things that effect reproductive rates are hydration and ph.  Higher hydration favors yeast reproduction over lab reproduction and lower ph hinders yeast reproduction more than lab reproduction.

DavidEF's picture

LAB is a kind of shorthand for lactobacillus. So, people around here call them (plural) LABs, cause it's just easier. They are the beneficial bacteria that help break down the flour and impart flavor to your bread.

I'mTheMami's picture

Yay! I was onlyoff on the spelling ;) your explantion was a bit more thorough though :)

DonBick's picture

I just recieved the Tartine book from my mother in law and I have a question on the starter. About 24 hours after mixing up the starter, it really poofed up (growing out of the container). At that point I did the first feeding, I discarded 80% and added more of the 50/50 mix and water. Since then I have not seen much activity. I have fed it once each day since then for about three days and I am not seeing it rise at all. The smell is sweeter than it was the first day.

Do I need to just be patient and continue feedings?

Thanks for any help, I am really excited to try my first Bake.




BreadBro's picture

You'll see a lot of initial activity, which will drastically slow down due to bad bacteria making lots of CO2 burps. As you feed the starter over the next week or so you'll see small signs of life. If you starter isn't going absolutely bonkers early on, don't panic and think its dead. It takes time for the good bacteria and yeast to build up.