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Long fermentation benefits

Ilya Flyamer's picture
Ilya Flyamer

Long fermentation benefits

It is often claimed that long fermentation makes bread better. I wonder what aspects of long fermentation are actually important?

  1. Acidity. With both sourdough, and in lower degree (but maybe even more importantly in that case) with CY, longer fermentation would lead to accumulation of acidity in the dough, and to an extent that is certainly a benefit.
  2. Gluten development, and later partial breakdown? Development just through time is certainly a factor for the baker, but not so much for the final product: it'll change the crumb structure compared to development up-front, but whether it's a benefit is a question of taste. Partial gluten breakdown might be considered a benefit, if it is to be believed that it's easier to digest in that state.
  3. Any other benefits of long fermentation? For example, does just letting the flour sit in contact with water for a long time, even without any yeast/LABs/etc bring any benefits flavour-wise, forgetting about gluten for a minute? Would enzymes in the flour generate more flavour, except sugar that would feed the yeast?

Why I am thinking about this, is CLAS is supposed to bring excellent quality, but much faster, by bringing acidity and other fermentation flavours. This way one can make a bread with a relatively large amount of yeast and quickly, and still get a lot of flavour. But I am wondering if this process would miss out on some other benefits of long fermentation?

jl's picture
jl

If you maintain your own starter, you can tell the whole world to go gently caress themselves and still be able to make bread, as long as you can get your hands on some grains. Would it be hard to cultivate just the baker's yeast on your own?

I remember seeing some YT video of some Russian dude obtaining some very distinct starter from an old lady somewhere in Belarus (?). So, things produced by other microorganisms maybe?

Ilya Flyamer's picture
Ilya Flyamer

Using a traditional SD starter is not the same as having a long fermentation, which I was interested in: you can have a long fermentation with just commercial yeast, if you use a very small amount.

Cultivating baker's yeast is trivial in the lab! At home I guess one could go down the yeast water route too, which is very easy as well.

Well, the idea of very distinct starters - I don't know, I won't believe it until I have a direct comparison side by side... It's mostly about maintenance, what determines the qualities, it seems.

alcophile's picture
alcophile

It would be very interesting to know what other minor flavor components are generated during the fermentation process, CLAS or otherwise. I suspect these may be the most important flavor contributors in the final bread. The acidity can be replicated by just adding organic acids (lactic, acetic, possibly malic, etc.), but it's those minor components that are key.

I used to be fascinated reading studies of flavor components present in various foods. Many of these were published in the Journal of Agricultural and Food Chemistry and other journals. I was always surprised at what chemicals are naturally present in foods.

Ilya Flyamer's picture
Ilya Flyamer

That would be interesting! But also, would be interesting to know whether they are produced by fermentation, or on its own in flour when it gets in contact with water.

alcophile's picture
alcophile

I would hope the study would include control breads with yeast and an unleavened bread (gonna be really flat!) for comparison. If I had access to SciFinder or another scientific search engine, I might look to see if anybody has published this. I do know that there have been some studies analyzing the acid composition in San Francisco sourdough. Fresh Loaf member doughooker has posted some info on this if you are interested.

Here are some other articles I found with Google; some are behind paywalls:

Sourdough volatile compounds and their contribution to bread: A review

Characterization of Artisanal Spontaneous Sourdough Wheat Bread from Central Greece

The diversity and function of sourdough starter microbiomes

Now, if I just had a GC/MS with SPME headspace analysis capabilities…

mariana's picture
mariana

It's an interesting question, Ilya. 

I only see psychological benefits, nothing else, in long fermentation. By that I mean if I wanted to bake a certain kind of bread and there were several ways of making its dough which resulted in the same kind of bread, then I would choose one that suits my timing, my work schedule, my psychology, or actual needs for a quick loaf or for something that should be ready tomorrow by 5PM or something. 

That said, some breads have to be made using long fermentation route and very little yeast. They cannot be made using CLAS and huge amounts of yeast. Their very nature would change, their flavor would become different, etc. The same could be said about the opposite kinds. Some breads are quick, that's their nature. Long fermentation would affect their character and their flavor. 

Your thinking is different and from the opposite end. You think as a bread designer who wants to discover how to manipulate the qualities of bread to create a loaf with certain characteristics by manipulating one factor - the length of its fermentation, maybe along with changing the amount of yeast in it or adding a flour or bread improver, such as CLAS or dried sourdough starter which is loaded with acids and aromas but doesn't really ferment inside dough per se.

Your thinking about baking with CLAS is along the lines that emerged about 100-200 years ago when bakers began to shorten their bread making routines getting away from prefermented doughs of old times to straight dough, to no time dough and dough with souring agents, such as CLAS and dried sourdoughs.

One of the latest attempts was No-knead 2.0 and 4.0 by Kenji Alt-Lopez from Cook's Illustrated kitchen. They created an improved version of no-knead dough that besides its very long and slow fermentation at room temperature relied on souring dough with vinegar and flavoring it with beer (2.0) and giving it 3-5 days in the fridge (4.0) in order to accumulate more flavor to make it more like "real" bread. 

The only benefit to it that I see is that longer fermentation allows more time for gluten formation. Not development, but formation, % of gluten formed. Some breads could be made from straight dough in a couple of hours, such as challah or straight dough baguette, but if you give them additional 3-24 hrs in the fridge, not fermentation time but cold storage time, their crumb magically changes, it becomes so much better. 

- does just letting the flour sit in contact with water for a long time, even without any yeast/LABs/etc bring any benefits flavour-wise, forgetting about gluten for a minute?

- if you let it sit, it will rot and stink, no beautiful aromas, none. Anyone who started their sourdough starter from scratch by using only flour and water knows that. Depending on flour, it would begin to bubble due to bacterial fermentation and stink within hours at room temp. 

Ilya Flyamer's picture
Ilya Flyamer

Thank you Mariana, very interesting comments, as usual!

Btw I thought CLAS would ferment inside the dough too, particularly with warm fermentation conditions?

Right, cold storage time, I kind of meant that as either a long fermentation in the fridge, or just getting the floor wet in the hypothetical example (and of course storing it in the fridge if it's longer than an hour or so! Don't want it to rot, like you point out). Would you say this would affect the crumb structure, but no so much the flavour then? And in what way is it better?

mariana's picture
mariana

Ilya, with sourdough, there is a lag time about one hour long, when the microbes adapt to the new environment (sudden high dilution is stressful for them) and only then begin to ferment in earnest. And straight dough with CLAS usually ferments under one hour. 

Still, I suspect that what you use is not really CLAS strictly speaking, but some kind of starter that RusBrot invented and nicknamed CLAS, and that the recipes that you use are something else, not necessarily under one hour brief. So, in order to know for sure, you could measure your dough acidity, both its pH and TTA, to determine how it changes with time, whether your CLAS works only as an improver or as a genuine sourdough. 

I don't know much theory of baking, but from practice I know that when you have a lower quality flour, for example, plain British flour with let's say 10% weak protein, and use it in yeasted or sourdough baking, then your bread dough would benefit from overnight storage and bake into a taller and more beautiful loaf with silky lacy crumb. 

The same strange effect I observed with our Canadian strong flours which are way too strong for, for example, French bread baking. Let's say baguettes made with straight dough: bulk ferment for 1.5-2 hrs and give it 30-45min proof, then bake. Van Over in his book The Best Bread Ever suggests to give it 3-4hrs or 12-16 hrs in refrigerator at 37F/3C after bulk fermentation and see how it affects the crumb and bread flavor. I tested it and discovered that 3 hrs gives me the desired very French crumb, tender, shiny, lacy, despite my flour being Canadian, totally unsuitable for baguettes, and no noticeable damaging effect on flavor, but 12-16 hrs negatively affects the flavor, makes it way too sour, sharp, thick, not baguette-like at all. 

 

Ilya Flyamer's picture
Ilya Flyamer

I see your point about lag time, that makes sense. But why do you say Rus Brot's CLAS is not really CLAS? He didn't invent it, he just found some convenient ways to make and maintain it at home... It's very sour (I don't have a pH meter, but he reports pH 3.5 with his best refreshment scheme), refreshed at 40°C, so no yeast. What is CLAS if not this?

The recipes are quick, but not under 1 hour. For white wheat doughs he recommends 2-2.5% fresh yeast, and bulk ferment is 1.5 hrs.

Thank you for sharing your experience! I can certainly tell that the crumb is different in the breads I've baked recently with CLAS and much quicker process, but I wouldn't say it's worse. The bread tends to be much softer (both the crumb and the crust, actually) and I think I get bigger volume for the same weight too, but I haven't compared directly. And I don't think the flavour is worse either, just a different profile...

But what I was interested in is if I could combine the simplicity of CLAS with longer fermentation - would that give any benefits? For example, I go much quicker through bulk fermentation and shaping, but leave the loaves for final proof in the fridge overnight, as I often did with traditional sourdough. I asked Rus Brot himself, and he doesn't see much point, since he says CLAS produces superior quality bread with a very short time. But I was curious if I could somehow combine the best of both worlds - does longer/slower/cold rise give anything in addition to flavour development. I'll have to try and see how it affects the crumb structure!

Yippee's picture
Yippee

Hi, Ilya:

If you cold-prove the dough overnight, what% of CLAS and yeast would you use? Suppose you keep the percentages of CLAS and yeast unchanged, for example, 5% (3% for AP) and 0.7% respectively, in Rus's Palyanitsa formula. In that case, the dough might degrade overnight under such acidic conditions and over-prove as well. How would you tackle these potential problems? I have similar concerns about the workflow that I proposed to you the other day. Also, is fridge temperature optimal for LAB activities?  

Yippee

Ilya Flyamer's picture
Ilya Flyamer

Good question, I don't know the answer.

But when I prove regular sourdough bread overnight, it doesn't become significantly sour. And CLAS LABs would be slowed down a lot by cold fermentation, just as usual. So perhaps it would work just the same, regarding acidity?

I'm more worried with the normal amount of yeast it would overproof in the sense the dough will keep growing too quickly for too long and will escape from the bannetons and lose strength. But maybe just reducing the amount of yeast more similar to what's done for long fermented yeast breads would work to avoid that? I'm fully aware that will be a completely different bread at that stage, but still I'm curious how it will be different, and whether there would be any benefits to doing that.

Yippee's picture
Yippee

cos I'm about to make another loaf of Palyanitsa. Since I'm not familiar with cold retard and long-fermenting yeast dough, approximately how long and what % of yeast would you recommend? 

Yippee

Ilya Flyamer's picture
Ilya Flyamer

Oh interesting! I've never tried it with yeasted dough either - I never baked with yeast before doing sourdough, so it's also new for me. But I would check Rus's recipe for ciabatta for the amount of yeast - that's I think the only one where he combines CLAS with cold retard. He does it there for 24 hrs, but just overnight should be fine to try.

Yippee's picture
Yippee

https://www.youtube.com/watch?v=beEhMiwIaHw&list=RDCMUCzOqEDC3PZUUgv2rW05ddiA&start_radio=1&rv=beEhMiwIaHw&t=43

I can't find a video with the Eng sub. It looks like he bulk ferments in the fridge? Could you tell me his timing for bulk and proof? I can use Google to translate the ingredients but not the procedures. Thx.

Yippee

Ilya Flyamer's picture
Ilya Flyamer

Oops sorry, I wasn't at home and forgot he didn't make English subtitles for this one. Yeah that's the video. He bulk ferments at room temperature first for 1 hour, then folds the dough, and only then puts into the fridge for 24 hrs, with a fold half-way. And for that he uses 1% fresh yeast. I think for a Palyanitsa-inspired col-fermented bread, I would also use 1% yeast and do bulk just like normal maybe for a more familiar flavour, and then shape and put in cold retard straight away. Perhaps make sure it's not too warm when it's shaped, otherwise it'll continue fermenting too much in the beginning - maybe cool down the whole dough a little first, and then shape? It's an experiment, not sure what to expect! Hope it's not a loaf you were planning to gift to a relative :)

Yippee's picture
Yippee

if it fails, it's all your fault

Ilya Flyamer's picture
Ilya Flyamer

I'm ready to accept it, hoping we learn something from it! 😀

As long as you are using the flour and spending your time 😜😆

Yippee's picture
Yippee

After taking the ciabatta dough out of the fridge, at what temp and for how long did Rus prove it? After overnight proof, I suppose I have to let the dough rise for some time before baking??? Do you normally bake it straight out of the fridge after cold-proof? 

Yippee

Ilya Flyamer's picture
Ilya Flyamer

I bake directly from cold. Makes very nice oven spring! And very easy to score.

He lets it warm up for 1.5 hrs, then shapes (by just cutting in half after a few gentle folds) and proofs just for 15-20 min at room temperature.

Yippee's picture
Yippee

Hi, Ilya:

I only used 0.15% dry yeast, half of what Rus used in his ciabatta recipe, but it still seems over-proved (what do you think?) 

My workflow:

Bulk - 33C x 90mins

cooled in fridge x 75 mins before shaping

Prove in fridge x 15 hrs

Bake per recipe

I didn't notice any difference in the taste-there is no apparent sourness, but the aftertaste is tangier, and it lingers longer. The version I made per Rus's instructions is much better than this experimental loaf in every aspect. That's why I don't mess with his recipe.

 

 

Ilya Flyamer's picture
Ilya Flyamer

Interesting, thank you for trying and for sharing Yippee! Sorry for the disappointment.

Why do you think it's overproofed? It looks nice to me, I can't judge the taste of course. Could be just more acetic from the cold final proof...

Yippee's picture
Yippee

but I'm sure it's not spot-on. Because when it's done right, it should look like this:

or this

Any ideas? 

Ilya Flyamer's picture
Ilya Flyamer

Wow those are beautiful! Do you get a crispy crust on them by the way? Since I switched to CLAS+CY the crust loses crispness almost immediately after baking, the only downside I've found.

Interesting that this one is so different. Did it noticeably grow in the fridge? Maybe crumb will reveal something deeper inside the loaf...

Debra Wink's picture
Debra Wink

Yippee, your second photo shows what happens when there isn't enough gluten to hold it together during oven spring, either from premature or excessive breakdown, or not enough collective gluten in the flour mix to begin with. I've seen more exaggerated examples of this where it can look more ripped and rough in the bloom as it just sort of splays out to the sides rather than rise up proud in the middle.

Pretty orchid!

Yippee's picture
Yippee

Thank you for pointing it out to me, Debra.  I used Central Milling Beehive AP flour in both loaves.  If the loaf in the first picture looks fine, then the flour probably did not cause the problem.

P.S. The two loaves in the pictures were made nearly a year apart. Is it possible that the flour has started to go bad? I baked the loaf in the second picture in May 2021.  Two subsequent bakes in June using the same bag of flour failed because I couldn't develop the dough as usual. The mixed dough looked ragged as if it had been corroded by acid. This abnormal dough phenomenon puzzled me greatly because I have made this bread numerous times and have never encountered such a problem. Thankfully, I've used up the entire bag of Beehive flour. Therefore, the experimental loaf was made with 365 brand AP flour. 

Assuming the flour wasn't the culprit, what else can I do to maintain gluten integrity in the future?

Thanks!

Yippee

Debra Wink's picture
Debra Wink

Hi Yippee, I might suspect the change of seasons more than the flour. I don't know where you are, but if it was getting warmer May-June, that may have pushed things over the edge in your doughs. Gluten degradation happens faster with warmth, water, and acidity in combination with the enzymes. Maybe the flour had a high level of enzyme, or maybe your starter was more acidic, or maybe the fermentation conditions were warmer than usual, or maybe some combination of two or more of those things. Warmth and acidity often go hand in hand. If you can figure out which of those parameters might have gotten out of control, you can reign it in by using less starter, reducing the hydration in the dough, or fermenting the dough a little cooler, whichever you think most applies. And of course, not fermenting too long for the prevailing conditions.

Yours actually looks quite mild compared to this ugly loaf that was made with a liquid starter and fermented very warm for what I'm used to. I started seeing proteolysis in the outer skin before the end of proofing:

dough degradation

I knew it wasn't going to be any good, but went ahead with scoring and baking anyway:


And here is a loaf that just had too much pumpkin in it for the gluten to hold it together. I couldn't find a photo from the top, but it was splayed open wide like yours. You can imagine how ripped it looked from its silhouette. No cute little bunny rabbit here :)

It actually had really wonderful flavor, if I could just get it to hold its shape.

Your bread looks great compared to these :)
dw

suave's picture
suave

"I thought CLAS would ferment inside the dough"

 

It can, and the literature suggesta that when it is allowed to the bread is better for it, but is not the actual reasoning behind it.  It was developed strictly as a self-propagating souring agent for plants without the night shift.  You know, so that the workers could open the place up at 6 am, and start loading trays with bread by 8.

Ilya Flyamer's picture
Ilya Flyamer

Thanks suave - you are right. I didn't think of the lag phase, and with such short fermentation times in white dough LABs won't have much time to ferment, if any.

It'll be different for non-white doughs though, for them the recommended process is still long and not that different from more traditional recipes. The biggest saving of time would be for simple white breads, or I guess significantly enriched dough where sourdough yeast would be slowed down a lot, while CY will power through.

suave's picture
suave

You can sort of do the math.  Typically CLAS is used at ~18 ww% to the total dough, and its TTA is twice that of the final dough.  This means 35-40% of final dough acidity is brought directly with CLAS, and the rest is generated along the way.  In a regular process for a similar bread you would use something like 30% of sour and the final TTA is ~75% of the TTA of the sour.  This translates to the same 30-40% of acid arriving with the preferment, so yes, if you measure things purely by acid production it's not that different.  I've gotta wonder if this is exactly how they came up with CLAS loading rates.

Ilya Flyamer's picture
Ilya Flyamer

Wow cool maths, I didn't know these numbers. Interesting. For what kind of dough is that, white, whole wheat, (whole?) rye?

Does it suggest CLAS is actually faster at producing acid than traditional SD even at regular temperatures, if the fermentation times are shorter, while acid production is similar?

suave's picture
suave

CLAS is typically mentioned in conjunction with mixed rye/wheat breads, and fermentation times used are twice as long as with traditional starters.

Ilya Flyamer's picture
Ilya Flyamer

Mentioned where? Rus Brot uses and recommends it for all kinds of bread. And earlier Mariana here was also saying it's used with very short fermentation, and I assume that was for white breads...

mariana's picture
mariana

Ilya, we are mostly consulting a couple of technological instructions for bread production issued by the institute of bread industry in Russia.

They mention  the following schedule for any wheat bread with wheat CLAS, not rye. Wheat CLAS looks milky white, made with white flour. 

95-97% wheat flour

yeast as in bread formula + 0.5-1%

salt as in bread formula

water as needed

other ingredients as in the bread formula

7.5-12.5% CLAS* (3-5% of all flour comes with CLAS, its TTA 14-18grad)

mix for 3-4 min, DDT 30-34C

bulk fermentation 40-90 min depending on the amount of CLAS and its TTA, 

*10-12.5% CLAS for bread dough

7.5-10% CLAS for enriched dough, Vienna dough, etc. 

With rye CLAS and rye bread or rye/wheat blends the schedule is as suave says. 85-90% flour, the remaining 10-15% flour comes with CLAS, DDT 31-33C, bulk fermentation 2-3 hrs. Rye CLAS TTA is much higher, about 18-24grad, depending on its hydration and choice of flour. 

Ilya Flyamer's picture
Ilya Flyamer

Right, thanks mariana! Nice to have all this info here.

I forgot about the possibility of wheat CLAS. Have you tried making/using it? Andrey / Rus Brot suggests for home bakers there is no benefit of maintaining a second, wheat CLAS starter, and the rye one can be used for wheat doughs - and so far I've enjoyed the results a lot too.

mariana's picture
mariana

Ilya, I know only two persons who bakes at home with Rye CLAS, a friend of mine from Germany and another one - from Spain. The rest of them, me included, bake with white CLAS based on regular bread flour, no rye CLAS at home at all. 

There are two reasons for it. First of all, I like freshly baked 100% rye for breakfast and it is very easily made by using rye kvass, a very liquid rye starter, basically, it's yeast water, but with sourdough bacteria as well. With rye CLAS such a feat is impossible: to wake up, mix rye bread dough and soon shape it and bake it for breakfast. 

Second, wheat CLAS is a great improver for wheat breads and enriched baked goodies and allows to prepare dough for them in a regular bread machine, using 'dough' cycle which happens to last about 40-70 min. If you bake a lot more pure wheat and wheat-rye blends than pure rye and rye-wheat blends, then wheat CLAS is the one to keep. 

Again, RusBrot's CLAS is a completely different animal, both the process, the result, and the use is different from the one I am referring to. Which is this one, it usually takes me about a week to develop and stabilize the culture and get the flavor right: 

https://registrr.livejournal.com/94444.html

https://registrr.livejournal.com/38356.html

For wheat CLAs the process is the same, except you'll need 0.5-2% of diastatic malt in the mix. Once your whole wheat CLAS is ready, you can shift it to white bread flour and keep it that way. 

Gadjowheaty's picture
Gadjowheaty

Playing major catch up today in general and happened upon the energy exploding on this thread - this is a motherlode, thank you for the thread Ilya and mariana et al for this incredible work.  Feeling out of my league and I'll have to sift through this stuff slowly but just to confirm, mariana you're saying a wheat version of these formulas replaces the rye flour 1:1, with in addition the 0.5-2% diastatic malt?

mariana's picture
mariana

Hi Paul!

Yes, the process is the same, it's the same flat starter, which can bubble and even double in volume, albeit rarely so, but only due to the gassing lactic bacteria, not yeast. The same schedule of feeding, only with whole wheat.

Our whole wheat and whole grain wheat flour, let alone bread flour, is normally already malted or supplemented with amylases, it says so on the bag of flour, but if you mill your own or buy non-malted, then either add 0.5-2% diastatic malt or 5-10% malt syrup to your mix, so that it has enough sugar for the process to proceed in time. 

Gadjowheaty's picture
Gadjowheaty

Great, thanks mariana.  On the malted flour, thanks, forgotten.  My basic BF is the Central Milling (malted) Baker's Craft though they sell an unmalted version as well.  I am looking to mill, so appreciate the note as I would have surely forgotten.

Looking forward to this!  This, and Hamelman's Swiss Farmhouse bread with raisin yeast water look to be very interesting new methods.  

I'm particularly interested in your mention of kvass, and would like to learn more.  I forget where it was I mentioned it, but it's interesting to me that the first thing the young Russian woman at our local Russian store said to me when I asked if they carried Borodinsky was if I was making kvass.  I have to admit I drank kvass once, got it from an awesome Polish deli in Chicago (Andy's.  Incredible, anyone in Chicagoland), and didn't care for it but then I doubt I had a good representation.  But your comments, as usual, spur me on to want to learn so much more, in terms of these methods. 

Many thanks again for everything you do for this community!

 

Paul  

mariana's picture
mariana

Paul, for the purposes of this thread kvass is just water on top of the starter, or water in which a ball of starter is floating, what you would call hooch in English. It's just that in case of hooch it separates spontaneously, when liquid (150-200% hydration) or semi-soft (100%hydration or so) starter sits for too long, whereas for kvass as a starter it is made very liquid since the beginning so that there is a solid or semisoft sediment at the bottom and lots of liquid on top. In kvass you would have a tablespoon of flour for 1 cup of water, so it's a super liquid sourdough starter. 

That liquid is full of acids, some alcohol and yeast and bacterial cells and it is used as a regular starter to initiate fermentation in sponge or bread dough. It has normal gassing power of a regular starter, meaning that if you use bread flour and kvass to make a piece of bread dough it would quadruple in 8 hours at room temperature. And rise more than that, 7-8fold increase in volume if you let it rise for full 12 hours.

 

You can make that simple flourless starter on top of the regular starter by pouring water on top of your starter and keep it for a while. Eventually your regular sourdough starter would release acids, alcohol and some yeast and bacteria into that liquid et la voila, your kvass is ready. You can either drink it as is or sweetened to taste or you can use it as liquid in your bread formula, it will both flavor and leaven your dough just as any regular sourdough would. 

 Here you can see two refrigerated sourdough starters about 150% hydration each. One is still rising (on the left), another is already cold and deflated, some clean water was poured on top of it and in the fridge, as the starter was sitting there, in one week a pint of kvass was formed. It is brown, because the starter which is at the bottom had some malt syrup added to it, for the fermentation to continue in the fridge. So, in the jar to the right there are two starters, one is flour based, and another is flourless, both can be used in baking with equally good results but the one on top could also be used as a refreshing drink, it has acidity and sweetness of Coca-Cola, or as a base for cold soups and hot borscht.  

pH and TTA are simply numbers that define readiness of some ingredients in baking: starters, preferments, bread dough, etc. They are used to define bread quality, to express some parameters of quality in writing, when you cannot show another person in person how acidic it is to taste (pH) or how fragrant it should be (TTA), especially since everyone's nose and taste buds differ. 

In Germany, they indicate both parameters in their bread formulas for professional bakers. In France, I only saw pH (in Calvel's 'Taste of Bread' for example, to track the point of maturity of sourdough, since at pH =4.2 gluten reaches the point of being fully hydrated and such sourness is what pleases French bakers and French consumers). In Russia, they only use TTA as more precise method of pinpointing the moment of the starter or dough being ready for the next step in the breadmaking process. pH is way too broad and nebulous, because to each pH corresponds a wide range of values of TTA in the same dough, one would be that it is not mature yet, and the other end of TTA that would indicate that it is way past its prime. 

Titration at home is super easy, easier than taking pH measurements, actually. Well, at least it seems to me that way.

Still, most folks either don't need it at all or psychologically are very resistant to it, until they face problems with breads akin to one that you saw in your loaf baked with thermophilic starter. Issues with crust, with crumb, with taste and flavor all indicated that TTA was not in the target zone. You either didn't know that you had to track that parameter or you skipped it and saw what happens when you only track time and temperature but not signs of maturity of dough on each step. 

CLAS is not CLAS either unless it has a very peculiar smell of honey sweet plums and target TTA which it achieves in prescribed time at prescribed temperature. Otherwise  you have no way of  knowing what you created, a genuine CLAS or some other yeastless starter which might be great and all, but not CLAS in the original sense of the word. 

best wishes, 

m. 

Gadjowheaty's picture
Gadjowheaty

Thank you mariana!  I am eager to try the kvass method.  Also the true CLAS method as you've laid out and as shown in the links you earlier provided.  Seems like a very fruitful area to dive into.  

For the Latvian bread I made, you have it right, I didn't take any titrations at all.  I followed the RusBrot recipe, and there wasn't a discussion of the parameter.  In reading your comments and those of alcophile, I now see how valuable it is as a measure.  I was aware one could have the same pH but widely different TTA values but basically ignored the ramifications. 

Where I've seen any discussion of measuring acidity, I never came across TTA  being mentioned until diving into these Baltic and Eastern European breads. I'm eagerly awaiting the book Gutes Brot by Roswitha Huber to arrive (think I got the the idea from the Lutz Geißler - Plötzblog site), and am curious whether she uses TTA in the book (do you know?  Wondering how "home books" v. "pro books" deal with the parameter).  

So, another world that I see has great value.  Thanks again.

I have all the titration gear from my cheesemaking days, including the reagents still.  Just find it more cumbersome than my portable Milwaukee MW102 pH meter.  For the meter I use a 2-point calibration, rinse with DI from a lab squirt bottle and get good enough values for my brewing and cheesemaking.  Nevertheless, it will be fun to set up the burette stand again.  I suspect it's only "cumbersome" because I don't do it regularly, and with time it will be second nature.

Would also be nice not to have to worry about a faulty electrode!

Edit:...except I see the method used in the video includes a pH meter, lol.  I've used both a meter and phenolphthalein.  Of the two, I much prefer the meter because reading "light pink" is never precise enough for me.

The meter method I used was the same as shown in Paul's video for the most part but I was using pH=8.2 as an endpoint, not 8.4 (I was also using liquid whey, so the process was slightly different in terms of diluting the sourdough titrand v. just using the known amount of whey).

Thoughts on pH 8.2 v. 8.4 as an endpoint?

 
Gadjowheaty's picture
Gadjowheaty

Thought I should just do another post, specific to gear.  I've nowhere near the quality of g scale as shown in Paul's video.  Mine's just a500 x 0.01 g "Smart Weigh" scale.  For these purposes, would this [less than lab quality] scale suffice?

Otherwise in terms of a burette, I've a United Scientific 10 ml, Class A, with a PTFE straight bore stopcock.  Am I right in thinking a 50 ml burette would be needed, going by Paul's video?

alcophile's picture
alcophile

The gear is probably OK. It depends on your sample size—the minimum and maximum quantities you are measuring. The minimum weight that can be measured on balances and scales is determined by the repeatability of the scale and the required accuracy. But this is only important for serious analytical lab work and you're not performing lab work for a commercial bakery. Class A volumetric ware is about as good as it gets (only serialized Class A is more expensive). You can always adjust your sample down slightly to stay within range of the 10-mL buret or refill the buret (less convenient and the reading may drift while you are refilling). The titrant used in the video was 9.2 mL.

Concerning the pH 8.2 vs. 8.4 endpoint, I can't comment except to say that it is close to where the phenolphthalein color change occurs. I can't view the AACC 02-31.01 for TTA (paywall) but I suspect it may specify that endpoint for the titration.

Gadjowheaty's picture
Gadjowheaty

The gear is probably OK. It depends on your sample size—the minimum and maximum quantities you are measuring. The minimum weight that can be measured on balances and scales is determined by the repeatability of the scale and the required accuracy. But this is only important for serious analytical lab work and you're not performing lab work for a commercial bakery. Class A volumetric ware is about as good as it gets (only serializedClass A is more expensive). You can always adjust your sample down slightly to stay within range of the 10-mL buret or refill the buret (less convenient and the reading may drift while you are refilling). The titrant used in the video was 9.2 mL.

Thanks alcophile.  Unfortunately I don't know how to change the calculation if I drop down in sample size.  I seem to recall something about molecular weight but honestly I've forgotten it all.  Also, that was with whey, already a liquid.  Does it matter if you start with a stiff starter and dilute it with, say, 500 ml. of DI instead of his 10.25 g starter, 100 ml DI?  He's got (quantity of NaOH 0.1 M used )/(grams sourdough starter) x 10 = TTA.

Is it the case the amount needed to liquify the stiff starter - say, 500 ml DI - is irrelevant, so long as you know the mass of your starter sample to begin with?  And say I wanted to make sure my 10 ml burette was enough - and my starter is much more acidic than his.  If I drop the sample size to say, 5 grams, what would the calculation be (sorry, I don't know recall the formula's basis, which is why I can't manipulate the weights and know how the equation should be set up).

Many thanks.

 

Paul

 

alcophile's picture
alcophile

I am unable to find a derivation of the total acidity equation that is used in the video and I don't know what the convention is on reporting that parameter. I did find another reference (BAKERpedia) that listed the endpoint at pH 6.6. The pH 8.4 endpoint is more appropriate to ensure complete neutralization of the weak acids.

The total acidity titration is insensitive to the structure of the acid (acetic, lactic, malic, etc.) as only the H+ is involved. Therefore, molecular weight is not needed for the calculation. It would only matter if the acidity was reported as "x g of lactic acid per y g of sourdough".

I think smaller portions of sourdough could be used because the equation shown was just a ratio of volume of NaOH to weight of sourdough. So, say 10 mL of NaOH was needed for 10 g of sourdough. It would also work for 5 g of sourdough but only 5 mL NaOH would be needed. The problem with the smaller sample sizes is the potential error of the measurement increases. The 50-mL buret would be more convenient; I was just trying to save some $$. You might as well follow the method as described.

I would not use more water to dilute the sample. It is unnecessary as long as the dough can be dispersed in the water. The titration vessel will become unwieldy and the endpoint response might be different, especially if you use phenophthalein (fainter).

Gadjowheaty's picture
Gadjowheaty

Thanks alcophile.  I hear you on the measurement error issue.  Seems to me the whole point is to get a moderately-accurate idea of TA, so it makes sense to just get the 50.  Thanks.

OK on the water.  Just wondering what to do with a stiff starter.  I have a magnetic stirrer plate and rod, used it for yeast propagation when brewing.  

Molecular weight - sorry, I used to do my own 0.1 NaOH solution, and forgot it was there were mw was discussed, relative to normality.

Gadjowheaty's picture
Gadjowheaty

Sorry - I hope this is relevant, if a more general question.  Ilya, if this hijacks the thread, will take it elsewhere.  

I know TTA is widely used in many industries.  Though my personal experience is that pH is more widely used in artisanal cheesemaking (and brewing), it's not uncommon for me to see TA in French farmhouse cheesemaking production, particularly with goat fresh cheeses, e.g., chèvre  (could just be my sampling is so low).

I find TTA to be a major PITA, and pH to be so convenient. Particularly when acid accumulation can happen pretty rapidly, stopping to titrate multiple times is something I'd prefer not to do.

I understand that TA gives us total acidity and says nothing about the buffering capacity of the sample.  In practice, why is TA used more often, as here, with these KMKZ techniques, for example?  What does it tell us that makes it a comparably better choice? (Flavor? - total acids, e.g., strong and weak v. free H+ only gives us a better qualitative picture?)

Thanks.

 

Paul

Ilya Flyamer's picture
Ilya Flyamer

I think we are beyond worries about going on long tangents in this thread here, but it's all useful and interesting!

I have some guesses about TTA vs pH, but having no experience with it in any production (and I haven't done any titrations even in the lab since university chemistry days) I'll first hope for more knowledgeable bakers to answer :)

alcophile's picture
alcophile

@Paul—You're on the right track with the strong/weak acid vs. free [H+]. The pH measurement does only correlate to the [H+] and the buffering capacity of the dough and the fact that the organic acids of interest are weak will affect the [H+]. I wonder if there is a work-around for TTA? I might poke around with the Google.

@Ilya—Really off the subject now: My coworkers in the lab thought I was crazy for enjoying the occasional titration. These usually were not acid-base titrations but slightly more complicated iodometric (for hypochlorite content) and Fajans (for chloride using silver nitrate) titrations. I guess I'm slightly old-fashioned, but I wanted to retain some of my skills for one of the classic "wet" analytical methods. I will say that the endpoint on the Fajans was a beast—probably the hardest I've had to interpret.

Ilya Flyamer's picture
Ilya Flyamer

Lol I don't remember anyone enjoying any titrations back in uni in analytical chemistry practicals! Always one of the three replicates was different from the two others. And missing the colour change and having to redo it from scratch is of course the all-time favourite problem. I don't remember whether we had to do any complicated ones...

Gadjowheaty's picture
Gadjowheaty

Yeah, my endpoint (of chemistry, not titrations.  Or rather, both) was very likely your Pre-K beginning points, so....just a tad out of my depth here, lol.

Why is TA used then, in practice, in the professional (baking, some cheeesemaking - esp. farmhouse, which seems almost perverse!) field?

alcophile's picture
alcophile

I can't say I know much about this from a baking perspective, but if your goal is to optimize the amount of organic acids formed in the dough (and not just the pH), then TA is important. There is no simple way to measure the weak acid content except through titration.

Here is a discussion of TA from Lallemand Baking: Preferments

Maybe a Fresh Loaf member has developed a simplified or streamlined TA method.

alcophile's picture
alcophile

I think I'm just a bit weird that way!

I hadn't done a Fajans titration in over 25 years and then had to reacquaint myself with it. I missed many an endpoint: a light pink color on the precipitated AgCl.

Gadjowheaty's picture
Gadjowheaty

Wow, your background sounds impressive.  The only Fajans I came across were at Oxford, and only found out the day after the pub crawl they were actually:

...I had to try.

alcophile's picture
alcophile

I am an acolyte at the altar of much more knowledgeable folks here at the Fresh Loaf and my background only helps so much with bread (still overproofing a bit). To paraphrase a postdoc I knew: "That [a degree] and 50 cents will buy you a cup of coffee."

But I did I learn something new today: that Kazimierz Fajans discovered the element protactinium.

Gadjowheaty's picture
Gadjowheaty

To be very clear, alcophile, I was joking (about my Oxfordian/Fabian connections; I am neither).  It is clear your background is impressive and I imagine it will come into play here sooner or later, if it hasn't already!

alcophile's picture
alcophile

I was also joking about the coffee.

The chemistry I learned over the years was fascinating but having a degree for it isn't all it's cracked up to be. I'm just another newbie here.

pmccool's picture
pmccool

while I was looking up information about TTA in bread dough: https://www.questforsourdough.com/blog/librarian-explains/how-measure-acidity-your

Paul

Gadjowheaty's picture
Gadjowheaty

Thanks Paul!  Subscribed.

gerhard's picture
gerhard

seems to remain fresh tasting for much longer than breads with yeast that go into the oven 2 or 3 hours after mixing started. Not smart enough to know what CLAS is.

Ilya Flyamer's picture
Ilya Flyamer

CLAS is concentrated lactic acid sourdough - a starter with only LABs and no yeast, so you'd combine it with baker's yeast.

Interestingly, in my recent and limited experience, bread with CLAS remains soft and fresh longer than I'm used to with traditional sourdough! Although again, haven't done a side by side comparison using the same overall formula.

Colin2's picture
Colin2

Hamelman, Bread, 2013, p. 13: "Of great importance for the development of bread flavor is the production of organic acids during fermentation. ... contribute significantly to bread flavor ... strengthening effect on dough structure ... improve the keeping quality ... Since the organic acids develop quite slowly -- it takes hours before they are sufficiently present to benefit bread flavor -- the use of pre-ferments, which mature over the span of many hours and are replete with developed organic acids, is a highly effective way of augmenting bread flavor.

McGee On Food and Cooking 2004 p. 539: "Long, slow fermentation allows both yeasts and bacteria more time to generate flavor compounds."

This is one of Reinhart's great themes, with far too many examples to quote.

So the claimed flavor benefits are more than just a one-dimensional "acidity."  I also see references in the lit to "volatile organic compounds."  I am in no position to test the truth of this rigorously, but home experience is that a poolish or stiff biga with a day of fermentation makes for a more complex flavor than a straight dough.  (This is largely CY experience FWLIW  --  sourdough differs because of its added constraints.)

Ilya Flyamer's picture
Ilya Flyamer

Thanks for the quotes Colin - as you say, do these refer to yeasted doughs or sourdoughs? Still, it seems in particularly Hamelman the main sources of flavour are acids.

But anyway, with CLAS, the reason I was wondering about this, you load a lot of acids and other flavours up-front. So perhaps some flavour compounds only generated by yeast would not be so prevalent, but the question is how much of flavour in sourdough is from yeast relative to LABs...

Colin2's picture
Colin2

Both apply to anything yeasted.  I know nothing of CLAS and by all means, you should experiment!  Re "sourdough," the trouble is the category embraces everything from hyper-sour LAB-dominated "San Francisco" loaves to much subtler levains.  In any case in my limited experience sourdoughs/levains give you much less flexibility for prolonged fermentation than CY, precisely because the LABs take over.  

alcophile's picture
alcophile

I agree the flavor benefits are more than just the acidity. I suspect the volatile organic compounds (VOCs) are very important to the flavor of bread. The identified compounds in the volatiles of the breads in the studies posted above are numerous and include the usual aroma/flavor contributors like esters, aldehydes, ketones, etc. If the flavor benefited from just the acidity, addition of relatively inexpensive organic acids would be all that was necessary to replicate the flavor of sourdough. There are subtle differences in the flavor of acetic, lactic, and malic acids, but the predominant flavor sensation is still sour or tart. But it is true that acidity interacts and affects the flavor of foods.

I would be curious to know if just the CLAS itself has been analyzed for VOCs.