The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Effects of fermentation and soaking question

venkitac's picture
venkitac

Effects of fermentation and soaking question

I don't know whether this question is geeky, but anyway: most lean dough recipes I've seen call for a poolish/biga fermented for a few hours (or retarded overnight) and then mixed in with a significant quantity of flour (let's say half poolish and half fresh flour or some such) to create dough, which is then again fermented for a small number of hours and then baked. I've a few questions about the effects of these:

- What if I make the entire dough, yeast and all, ferment for a couple of hours (or not at all), then retard overnight, de-chill and bake, versus create poolish, mix retarded poolish with fresh flour to create dough and bake? (The "Gosselin Method" in BBA is like the former). Is there a difference in flavor between these methods?

- Instead of using a preferment, what if we just use the entire flour quantity called for as a soaker, and then mix the soaked dough (unsalted and unyeasted dough) the next day with yeast and salt and then ferment for 3 hours and bake? I believe this is the original  Gosselin method. What would be the flavor difference for this method vs the above two?

- I've read books where they say "too much preferment sours the bread". From my minimal amount of baking, this doesn't seem true if you retard the preferment quickly. In fact, the Gosselin method in BBA is basically all preferment. Does that sound right, or is my taste too undeveloped?:)

Essentially, the first two questions boils down to this: we can soak all the flour overnight, or some large percentage of it. We can add yeast to all the dough overnight, or some large percentage of it. If we're retarding, we can retard immediately after mixing the dough(if we do the BBA Gosselin)/poolish(most other things) or we can retard a couple of hours later. These 3 variables create 8 different combinations, and I'm wondering is there a marked difference between the various combinations. I suppose a better question would be about the effects of all the variables involved. Bread geeks, help!

I'm not a consistent enough bread baker to try all this and say that "the difference in taste is because of this method vs that method", nor do I have strictly controlled conditions, hence I thought I would ask.

pmccool's picture
pmccool

If I can say it without sounding like a smart-aleck, how about doing a side-by-side of all three techniques (preferment vs. cold retarded ferment vs. soaker) and let us know what you find out?

I'm not really sure what your results might be, but I'd be interested in learning what happens.

Paul

venkitac's picture
venkitac

I actually want to do exactly that but I'm not very confident of my own baking or tasting skills (as I mentioned at the tail end of my looong post) to do a repeatable experiment to isolate what variable caused what result. I was hoping that someone actually knows all the chemistry to give a scientific explanation. Someone like Debra Wink?:)

If all else fails, I'll try all the combinations and post, but the results might vary because of small variations in whatever I do, which is my fear.  Let's see.

proth5's picture
proth5

 

and an invitation to discussion.

First, if you are not at least a somewhat consistent bread baker, just let me respectfully suggest that you are tying yourself up in knots with your questions.  There are many methods of producing bread and they will all have different results in your hands and under the conditions that you bake.   It might be best to pick a method and see how that works for you and then expand your repertoire.   There is no "scientific" explanation on all this as we are dealing with taste and handling qualities that are somewhat subjective.  This isn't formulaic.  Large scale bakeries will go to great lengths and run many analytic tests to adjust to conditions and flours, but we, as home bakers, must learn to respond to the demands of the living organism with which we work.   Anyway to attempt to answer your question. 

I'm going to assume (since you used "yeast" in your questions) that you are asking about breads with commercial yeast. Some of my answers would be different if we are talking about wild yeasts.

In general, the longer the fermentation time, the more "taste."  In theory, breads made with almost no yeast and fermented for very long times would be the "most flavorful."  However, there are tradeoffs that must be made in terms of time and space constraints (and how the gluten in the flour reacts to a very, very long fermentation) and a number of methods have been devised to coax taste from flour.

The poolish or biga (I prefer the term pre ferment) method takes a percentage of the total flour in the formula at a certain hydration, incorporates a small amount of yeast and allows it to completely ferment normally (not in a cool environment - usually at the ambiguous "room temperature") until it is ripe.  Ripeness is judged by the appearance/aroma of the preferment but is usually done "overnight."  So here is the first set of conditions - the amount of the flour that is in the preferment, the hydration of the preferment, the amount of yeast in the preferment, the ambient temperature and the time.  Pre ferments are generally not "retarded" - that is allowed to ripen in a very cool condition - although some people do it.  It is more typical to control the rate of fermentation in the pre ferment by varying the amount of yeast.

Now the question is how much flour to preferment.  I have seen formulas from very low percentages to very high.  When a very high percentage of the flour is pre fermented, the sugars/starches in the flour can be totally used by the yeast in the preferment and then some diastatic malt may need to be added so that the full amount of yeast in the full amount of flour can ferment properly. If too much flour is pre fermented and malt is not added, the resulting bread will not rise well. Perhaps that is what your author meant about "souring" the bread (or the author may have been referring to natural leaven breads - another topic.)

Once again, the longer the fermentation time, the more "flavor" in the pre ferment.

In general (although I know not always - so don't y'all pounce on me...) a bread that has a pre ferment then goes through a normal fermentation process.  It is not given retarded fermentations after mixing the full dough.  In theory this is because the benefits of long, cool fermentation have been obtained through the pre-ferment.  Or that's my story.

What does this do to the taste?  It adds the taste of long fermentation to some of the flour.  What does that do?  Well, pre fermenting a large percentage of the flour will add more "taste", but what I find is that I face tradeoffs in crumb structure with my hands and my altitude.  I tend to pre ferment a smaller amount of the flour than most folks and do a more thorough bulk ferment.  I have worked and tuned these factors until I have exactly the bread that I want (Note that I say "I want."  I am baking for me and a small group of folk who seem to like what I do.  Great tasting bread for me might not be what you want.  This is a subjective business.)  I make a formula, bake, taste, evaluate, take notes, and then tweak.  You will need to do the same. There is theory and there is practice.  This is a hands on craft.

The Gosselin Method as I understand it (and you seem to refer to it in many different ways) is an interesting variant.  It does a retarded partial fermentation with all of the flour and then adds additional water, salt and yeast.  This gives the benefit of a long, cool partial ferment on all of the flour. Note that I say "partial ferment "on all of the flour.  If a complete ferment was given to all of the flour, when additional yeast and water was added, there would be no food left for the yeast.  The bread would not require additional bulk fermentation time and would not rise well.  The cool temperature and small amount of yeast in this method is what drives the partial fermentation. More extensibility?  Probably.  More "taste"? Probably.  In your hands? You must try, bake, and taste. (So in terms of too much pre ferment souring the bread, the Gosselin Method does not actually do a complete pre ferment on all of the flour, so the bread should not be "soured.")

Mixing a complete dough (salt, yeast, and all) and doing a long cool bulk ferment gives the advantage of a long fermentation to all of the flour.  More "taste"? Most likely.  More extensibility.  Probably.  The presence of the salt will have an impact on how the gluten develops, but probably not too much.  This method has certainly been used with good success to give flavorful, very open crumbed baguettes.

And with that, we must consider the effect of the amount of yeast in the final dough - do we want maturity to occur slowly or quickly?  We can use a large amount of yeast and make a long fermentation by retarding the bulk ferment or we can use a very small amount of yeast and make a long ferment without retarding. Each of us has different constraints that will make different methods more desirable.  For example, I must produce bread from the mixing of the pre ferment to the cooled loaf in less than 20 hours.   My process has also been tuned for that.

(And no matter what, I will paraphrase what I have heard from no less a baking luminary than Solveig Tofte  - that getting an open crumb in baguettes is not a function so much of hydration, but of getting the fermentation correct.  In all these methods there is a factor of removing the bread from the particular type of fermentation involved at the correct time and degree of fermentation.)

When you talk of soaking all or some of the flour, you are talking about putting water to the flour in the absence of yeast.  This will allow the gluten to develop without fermentation.  This is often used with whole wheat flours - where it also softens the bran so that it does not slice the gluten strands.  It is used less often with white flours.  Soaking the flour is not a pre ferment.  It can be done at cool temperatures for exactly that reason - to prevent any wild yeasts from getting involved in fermentation.  So, soaking the flour is not really done with goal of adding "taste" - it is done with a goal of getting gluten to develop more thoroughly.  This may have more effect on bread volume than taste.

There are infinite variations and there is no "one true way."  Few of us on these pages have access to precisely controlled environments, but I will repeat my recommendation to try to bake the same bread a few times and only then evaluate and vary.  It is unfortunate that we do not have absolute consistency in terminology for bread baking, but sometimes we need to take a deep breath.  Learn to think in terms of the amount of flour that is pre fermented, the hydration of the pre ferment, the total hydration of the bread and the percentage of yeast in both the preferment and the final dough.  This is a very useful way to think about bread techniques and although some may have interesting variants, you can at least see those variants in the context of "normal" methods.

I hope this helps

proth5's picture
proth5

I tend to look at all this from a very practical standpoint. so, here goes.

While understanding the theoretical of using  a small enough amount of commercial yeast and a long enough retarded fermentation to allow bacterial action, in essence what we are doing as home bakers is using a moderate amount of commercial yeast and a short enough cold bulk fermentation time (usually no more than 8-12 hours) that I'm just not sure this theoretical occurance has time to occur.  Add to that the fact that high hydration "sourdoughs" kept at relatively cool temperatures tend to encourage yeast growth (as I have been told and sort of expereienced) and we're into the territory of "maybe it happens" in my tiny mind.  Or am I completely off base here?

I'd agree that a yeasted pre ferment develops a flavor, but here we are talking about fermenting at "room temperature" (in general) for 8-15 hours and I'm not yet ready to sign on that it develops the significant lactic/acetic qualities that we would get with a levain.  I would hope that they would be different - because this allows us different taste profiles.  I've taken a liquid levain pre ferment and put it into a commercially yeasted dough.  This is a very different flavor than a commercial yeast preferment in a commercial yeast dough (and I did not find it to be my "best bread ever"...)  I'm open to convincing, but my baking to date does not do it.

I'll go down with the ship over adding a liquid levain or a 100% hydration preferment to the autolyse.  I've talked about this at great length with folks who ought to know what Calvel meant.  I'm not budging on this.  You can't autolyse the full amount of flour with the remaining liquid if you do a high hydration pre ferment.  You cannot.  The pre ferment must be added and it's no crime.  If you think it is, then you must make a firm pre ferment to use autolyse.  The Gosselin method (and I hope this thread doesn't get found on "the Google" when people really want to know about those folks with 8 kids) has a small amount of yeast in the full amount of flour for a long, cold ferment.  I'm not sure that is a real autolyse - but that's where knowing the baseline helps us think a method through.  The method gives a long, cool, but not too thorough ferment at a low hydration to all of the flour.  This flour will have pretty nice gluten development, but since the yeast is starting to drown in its own waste but hasn't completely used all the available food it is a good candidate to get some more water, some more yeast, some knocking about and it will work well.  It should have a nice flavor because of all that flour that was fermented so long and will have good elasticity for the same reason.

I'm also interested in the complete fermentation.  Yes, punching down a dough does re distribute the waste products and allow the yeast to grow again, but at some point, the food is exhausted.  We see this in over proofed dough - or dough that has had too long of a bulk ferment.  Doesn't matter what you do - the thing is not coming back.  I know that if I stir down a fully ripe 100% hydration pre ferment, I won't be seeing much more action from it.  Perhaps the difference in the hydration levels between the pre ferment and the final dough are the difference.  On a practical level, I have seen as much as 42% of the flour pre fermented in a formula.  If that 100% hydration pre ferment is mature, you have not much food left for the yeast in the rest of the flour.  Something must be added. Or so the baker says.  What am I missing here?

I'm not a scientist (although I are an engineer).  I tend to try to do "single factor" experiments (although, my baking has reached a point where I can consistently turn out the same bread with the same formula week after week) but I know if I were a scientists I would find them replete with flaws.  What I have found useful though is to set parameters: I need to get the baking done from pre ferment to cooled loaf in 20 elapsed hours.  I want to use natural leaven.  Then I establish my desired mixing technique - by hand.  By this very set of parameters I have eliminated certain techniques (reatrded bulk fermentation and pseudo Gosselin for example...).  Then the variables that I mentioned can be varied to design the bread.  As in any discipline if we leave things too open ended we can glide into the paralysis by analysis mode and neglect making excellent bread in the pursuit of "perfect bread" (and if "my teacher" heard me say that he/she would not believe it.  Perhaps my time at "the place" did me good, after all)  What I have focused on in my bread evaluations is to identify the probable source of the problem.  Insipid taste?  Probably a problem with fermentation.  If I was careful about my bulk fermentation, this is probably an issue with how I conducted my preferment.  If I know that it was ripe, I will try to vary the percent of flour that I pre ferment.  Just can't get the thing to hold its shape?  Well, if I've been careful at all of the other steps, perhaps I have pushed the hydration too high.  That's why I emphasize baking a single formula (even if it is sub optimal) until you have achieved reasonable consistency.  That way when you vary one factor you have the memory of how the thing has performed in the past and can judge if you are closer or further from your goal.  When that bread is consistent and if you want to "improve" it - then you can vary one factor at a time once again.  Bear in mind that because of the tender age that I started baking bread and my own "decrepitude" I've been messing with bread now for a half a century.  I won't say I'm an expert, but I've had a lot of dough pass through these hands and frankly that colors my thinking.

Jeez we can get going on this stuff.  :>)  That's why, while I won't cop to ignorance on a lot of these topics, I tend to endorse putting them to back of the mind and let the bread do the talking.  But it is fun to chew over some of the more theoretical...

dmsnyder's picture
dmsnyder

I'm going to go stretch and fold some dough now.

David

foolishpoolish's picture
foolishpoolish

and correct me if I'm wrong but I believe the 'Gosselin method' is indeed a yeastless autolyse. Flour and water held overnight before yeast and salt are added. There's no yeast fermentation going on during that long resting period. It was Reinhart who modified the technique in BBA to add yeast before refrigeration. Perhaps you had it confused with Anis Bouabsa's baguette-making process?

FP

proth5's picture
proth5

I really am not too familiar with the "Gosselin" technique, so I looked it up on these pages on dmsyner's blog and found that yeast was being added.  Since I don't own a copy of BBA any longer it was hard to find other reference material.

So, I figured David gave me the straight scoop.  I stand corrected and more informed.

venkitac's picture
venkitac

Nit: I believe the BBA Gosselin technique adds yeast, but the original Gosselin technique used by Gosselin doesn't. Reinhart modified the original technique is my understanding - the "original one" mixes flour with ice cold water, soak for 12 hours in the fridge, then add salt+yeast and ferment and proof and bake. Correct me if I'm wrong...

dmsnyder's picture
dmsnyder

FYI, the following link has the formula Gosselin gave Peter Reinhart. In the Usenet post where I found it, Peter says Gosselin gave slightly different instructions to other visitors to his bakery.

http://www.thefreshloaf.com/node/8524/philippe-gosselin039s-pain-à-l039ancienne-according-peter-reinhart-interpretted-dmsnyder-m

And here is the original message from Peter, in its entirety: 

From: "s.reinhart" <s.reinhart@prodigy.net>

Subject: Pain a la ancienne--as originally shown to me

Date: Sat, 25 Jan 2003 08:48:36 -0500

Dear List Members,

Here is what Philippe Gosselin showed me, though others who have met him 

said that he did it differently for them. First, he mixes a dough of about 65% water to flour, with no yeast or salt, using very cold water. This is held overnight in the refrigerator, or what the French might call a long "autolyse."  The next day he remixes the dough, adding 1% fresh yeast, approx. 1.75% salt, and another 5% cold water. He suggested that with American flour it would be best to use 75% water, or maybe even more, depending on the flour. It makes a ciabatta-like dough, wetter than regular baguette dough (but not unlike the "Retrodor" baguette that is becoming popular in Paris these days--see the new Jeffrey Steingarten book, "It Must Have Been Something I Ate," for more on that excellent method). Gosselin mixes this until thorougly incorporated, about 4 to 6 minutes or so. This dough is allowed to ferment for 6 hours at room temperature, during which time it awakens and doubles in size (This is a big batch, so a small batch might awaken faster). The dough is then divided into baguette size (about 12 ounces), formed into a six inch torpedoes, rested for about ten minutes, in a bed of flour, then gently pulled, not rolled, to baguette length, placed on a baking cloth (couche) until enough are shaped to fill the oven. They are immediately taken to the oven, scored with a blade just as any baguette, and baked like other baguettes (about 460 F., equivelent). They nearly double in size in the oven, resulting in a crumb with holes somewhere between a regular baguette and a ciabatta.

My version is designed to make it more user friendly for non-professionals who don't have the luxury of baking shifts, waiting for 6 hours, etc. I think the results are fairly comparable, though a home oven can only take small lengths, not full baguette, so I advise making the pieces about 6 ounces for mini-baguettes. Of course, I also use the dough for ciabatta, pizza, and focaccia, though Gosselin doesn't use it for those purposes.

If anyone tries the more difficult method described above, I'd love to hear how it turns out for you. Good luck!

 

     Best Regards,

     Peter

David

venkitac's picture
venkitac

Thanks for the *super detailed* explanations, all. I can't say I have digested all this, I'll probably have to sleep over this and re-read this a couple of days:) I'll chime in with just one thing: the  comment about soaking doing nothing to flavor seems spot on. I took Paul's suggestion and ran 2 experiments with whole wheat bread (70% whole, 30% white, actually):

- Cold soak & retard all the dough with no yeast or salt for 12 hours, add salt+yeast, ferment for 3 hrs, proof for 45 mins, bake.

- Mix all the dough, salt, yeast and all. Immediately retard for 12 hours, dechill, proof, bake.

The latter was much stronger in wheat flavor than the former. In fact, I have never had such an intense whole-wheat flavor in any bread I have eaten, almost too strong a whole-wheat flavor. The latter bread, in fact, would have to be eaten as such and not with olive oil or in a sandwich, because the wheat flavor would mask everything else. (The only other food with which I have ever experienced such a strong wheat flavor is an Indian steamed wheat dish - pulverize wheat, autolyse 15 mins, steam, eat, really strong whole-wheat flavor). OTOH, the gluten development in the former was remarkable, it was like an all-white-flour bread, I could do anything with the dough really. But the flavor was much milder, and surprisingly, I got less of a rise out of it. (From one of the above posts, I now think it makes sense, it was probably over-autolysed and the yeast didn't do it's job fully).

Thanks again. I'm gonna print out the entire thread and stick it on the fridge. I'm kind of a bread geek even if not a great baker, and I've a read a bunch of books on this. But the above thread replies are actually more informative than any book I've read! Viva fresh loaf and thanks, all.

foolishpoolish's picture
foolishpoolish

From my experience and what I have read about the process - the benefit from 'soaking' (other than gluten development) comes largely from a longer period of amylase, thus freeing up more sugars. This has an impact both on perceived sweetness in the final product and also on crust colour and flavour. The 'gosselin' method that is often cited applies specifically to baguettes (or Pain à l'Ancienne) where both these attributes are important. Wholegrain breads may not benefit so much from this method (the dough in your experiment was 70% WW) - I believe someone here on TFL has come to similar conclusions from their own experiments.

My lay understanding of the enzymatic processes would lead me to think there is no reason why one should expect an increased 'wheatiness' from extended 'soaking' - this is something your experiment appears to confirm. However in my experience, slow fermentation or pre-fermentation of whole grains does bring out flavour in a way that fast fermentation of a direct dough does not. Again your experiment seems to bear this out. This is one of the reasons why, for example, when making a mixed wheat/rye bread, often the bulk of the rye appears in the levain/'rye sour' or pre-ferment.

In conclusion, what I think I'm trying to say is: the two different processes lead to different applications. Neither should be discounted as a blanket rule in favour of the other - but rather employed appropriately depending on the type of bread being made.

Cheers, FP

davidg618's picture
davidg618

It's true that there are bacteria that convert alcohol to acid. In the food industry the most common example would be vinegar (primarily acetic acid) is created by exposing alcohol to a specific acetic acid producing bacteria that "eats" ethanol. However, this is not the bacteria that is present in sourdoughs.

Some bacteria, just like yeast convert sugars into their respective waste products, i.e., CO2 and acids, CO2 and alcohol respectively. So some acid producing sugar eating bacteria may live side by side in some environments with some yeasts and compete for the available sugars. But eventually, due to different reproduction rates one species would dominate.

So how do sourdough starters continue to live stable lives for alledgely hundreds of years--if you believe the folklore? Therein lies the beauty of sourdough starters.

Sugar molecules aren't all the same. We've all seen, on food labels, words like fructose, glucose, sucrose, maltose, dextrose, and who-knows-what-ose. These are all different sugars, and their difference is evidenced at the molecular level. Rather then spend our time looking at the myriad differences, for this discussion it's important to know that some yeasts can't eat some sugars, and similarly some bacteria can't eat some sugars. If a particular yeast lives side-by-side with a particular bacteria, in an environment that contains sugars that each can eat, and each can't eat the other's preferred sugar; Eureka! we've got the Jack Spratt and his wife relationship. They can exist side-by-side, and lick the platter clean.

To get slightly more specific, from my Google derived reading--I'm not a biologist, neither micro nor macro, but I am a scientist, and I can read, and math is math--the most scientifically studied sourdough is--surprise, surprise--San Fransciso sourdough. The biologists have discovered the primary bacteria in SF sourdough is unique--appropriately, they included sanfrancisco in its appointed name, and it can, and does eat maltose. It's teamed with a variant of a relatively common yeast that can't eat maltose. Moreover, the SF bacteria produces other byproducts that prevent other organisms from living in the same environment--much like penicillin--that its yeast neighbor is immune to. There is a lot more going on too in a flour and water environment: e.g., temperature tolerance, pH tolerance, enzyme production, ionic bonding, and so forth; but this is the gist of their relationship: they can coexist, and so long as there is food for both, they coexist in a stable environment--for centuries, if you believe the folklore. So, simply put, we feed our starters, and keep them comfortable.

An aside: Subsequent reasearch has found the sanfrancisco bacteria in sourdough starters im many other places throughout the world, teamed with similar yeasts.

That is not to say there aren't other stable yeast, bacteria relationships in other starters, however, it is safe to say that to be stable their coexistance requires similar attributes.

David G