December 22, 2019 - 7:33am
Theoretical questions for understanding bread baking
Hello people,
my questions refer to yeast bread.
1. If I ferment two doughs for 10 hours: One will be bulk fermented for 5 hours and shaped and then proofed for 5 hours, the other one will be instantly shaped after kneading and proofed for 10 hours, will the end result be the same?
2. Will reshaping or balling always degas the dough, even by doing it gentle?
3. Are their two ways of overproofing? One is overproofing by too much gas and the other by dying of the yeast (no sugar left to eat) and producing off flavor and alcohol which attack the gluten network?
4. The overproofed dough because of too much gas, can it be rescued by reshaping?
5. Shaping baguettes and proofing in the refrigarator, will it stick to the couche?
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1. No. Proofing degrades the gluten network over time (built up acids degrade gluten proteins), making it somewhat weaker and more slack. We prevent (or better delay) this by stretch & fold and shaping, thus rearranging and strengthening the gluten network. The final shaping during the baking process is the last time you touch the dough, and since the proofing is already at a very developed stage, the final proof is often not that long at room temperature.
If you do a 5 h BF and a 5 h FP, the bread will still have a good shape or volume after baking (if you do a warm BF and colder FP). If you instantly shape it and leave it for 10 h without stretch & fold, it probably will just become a soggy mess and result in a puddle. Not because of overproofing, but because the dough wasn't rearranged and the gluten network became too weak.
This applies to standard breads, where you shape the dough with your hands, though. If you have a very sticky dough with a very fragile gluten network to begin with, e.g. a 100% rye, then putting the dough into the baking tin, proofing and baking will have a better result than reshaping the dough all the time.
Hope you understand, it's hard for me to put it into words.
2. Degassing is inevitable. But how much you degas the dough not only depends on how much you work the dough (by shaping and folding), but also on the quality of your gluten network. Especially doughs with higher ratios of weak protein (rye, whole wheat, spelt) need to be handled a bit more careful.
3. Overproofing means producing more gases than the gluten network can handle. But this will happen way before the yeasts run out of food. You can observe the process in your starter, it also falls together once there is too much gas to handle, and the yeasts still keep eating for many hours to come.
4. Kinda. It might give some structure again, but at this point the dough contains so many acids that the gluten network is struggling maintaining its shape.
5. That depends mostly on if you have floured the couche enough. After longer time it will also start sticking to the couche because the flour gets moist from the dough, but that usually happens way after the final proof is over (meaning if you leave it too long).
Thank you very much!
1. Actually I am trying to make a baguette with overnight proofing at the fridge. I want to put it in the oven in the morning. My plan was to bulk ferment the dough at the evening one day before, then shape it after few hours and put it in the fridge. Considering your answers this would be difficult to realise, right?
2. So if I shape the dough after BF it is not like I would start to ferment it from the beginning after kneading because it still contains CO2, right?
3.1. Usually most of the recipes contain much yeast in it. The procedure I've read in a lot of recipes is to rise it to double in BF, degas, rise again, shape and proof. So this means even after two times rising the dough is still not overproofed?
3.2. What is the purpose to use so much yeast? In Pizza recipes only a tiny amount of yeast is used to ferment the dough for example 24 hours at room temperature, so the dough is perfectly fermented after 24 hours without degassing it in-between times.
1. No, that's really easy to realize and a very common procedure. Bulk-ferment normally, pre-shape, rest, final shape, proof for a moment (about half the time of what you would do at room temp), just to kickstart final fermentation. Then move to fridge (called retarding or cold final proof). In the morning, score and bake straight out if the fridge.
There are a few advantages to this procedure: more flavor development, adjustability of baking schedule and better oven spring (the yeasts have a bit longer before the crust sets).
2. The moment you add yeast/starter to the dough, it's gonna start fermenting and it won't stop before all food is eaten up or the yeasts are killed. The point of shaping after BF has several purposes: to bring the bread into the shape you want and to build a skin that protects from too many gases escaping - you want those for a good oven spring.
3.1./3.2. I honestly never understood the point of degassing until somebody on this forum said it's apparently for redistributing the yeasts and food and to introduce more oxygen into the dough (for the yeasts).
But I never degassed my doughs and always get a very even, nice crumb. My theory is, if you do a couple of stretch & folds, you fulfill the purpose of degassing without actually degassing the dough.
But you don't need a lot of yeast for this. The whole point of using a lot of yeast is faster fermentation, because we are impatient ;) This is fine for a quick bake on the weekend, but if you want to develop a great product with more complex flavor, use less yeast (or at least a prefermented dough like starter, poolish, biga etc.). Time equals flavor.
Fun fact: another, more specific purpose of using a lot of yeast - this now applies specifically to sweet doughs - is to offset osmosis, thus having enough yeast power to even ferment the dough at all. The sugar in sweet doughs binds the water and makes it unavailable to the yeasts, rendering them almost useless, which can result in improper fermentation. If you use osmotolerant yeast, this doesn't apply. But no normal home baker has this specific yeast, so we just use more yeast.
Isnt it that gluten becomes stronger with time, not weaker?
Yes and no. As the flour hydrates, more gluten proteins form and the dough becomes stiffer. But (especially in sourdough), the built up acids slowly degrade the gluten strands (acids denaturate proteins), leading to more extensibility (dough becomes easier to stretch, it becomes slacker). Plus, the gases stretch the gluten strands, so there is also some force put on them.
Thats the reason why the dough keeps his form better when it is in the fridge? Because the fermentation slows down and gluten network isnt degraded that much?
Do you have a recommendation for a book about doughs which is scientific and explains the details about bread making processes?
Yes, and because cold temperatures make everything stiffer/harder, which you can observe in basically anything.
I would recommend "Advanced Bread and Pastry" by Michel Suas (San Francisco Baking Institute founder). It's incredibly rich, scientific and goes super into detail of every step in baking processes and how each of the ingredients contribute to and change the outcome. It gives sight into the industry and their terms
And, as the name suggests, it's not only about bread, but also quick breads (muffins, banana bread, pound cakes etc.) and pastries like croissants, pie crusts, cakes, mousses, sugar, chocolate and much, MUCH more. But a good third of the book is only about breads.
It costs a bit more (65-90$, depending on seller), but it's about 1000 pages and once you have it, you probably won't need any other baking book.
I'm sure there are equally great books out there which are only about bread, but I only know this one (since I don't need another ;D)