Percent Rise during bulk fermentation
First post here but I've been lurking around for awhile.
I've generally been following formulas primarily with SD and am comfortable enough with producing good bread (and pizza). My question is related to the bulk fermentation phase. I'm at the point where I am paying attention to dough temperature and the desired percent rise in this phase (prior to a cold retard). I'd like to start moving beyond the general formulas and one of the things that is throwing me is how one determines what the percentage rise in BF should be for a particular bread. Tartine uses 20%. Some other formulas use 50%. Some use doubling.
The analytical mind in me thinks there is something I may be missing in how the recipe developer determines what the rise should be prior to shaping. Can anyone enlighten me or clue me into something I should read to expand upon this?
Thanks! If this should be placed in another forum, let me know and I will move it.
Rising twice - before baking - is advisable. Enjoy!
Thanks. I'm aware of that. I'm looking for something a little more specific.
As the name suggests, this is the phase / stage in which the bulk mass of dough is allowed to ferment before being divided, but I guess the real question here is; why is it done and what purpose does it serve?
In essence, it is to allow sufficient leavening to occur such that the divided dough pieces can hold more less their form when shaped. The trapped gas from fermentation exerts an internal pressure against the walls of gluten within the dough which in turn contributes strength and structure.
With that in mind bulk fermentation can be applied to less or more of a degree depending on several other factors, including what type of product is being made.
Pizza is a good example, bulk is generally always short as you don't want to develop too much strength in the dough since it needs to be stretched out thin. With pizza, most of the fermentation time is offset into the proof stage.
Pan / Tin loaves which require a high rise need lots of strength however and would benefit from more bulk fermentation.
There are other factors that can impact these decisions but I'm sure you get the general idea.
More pre-ferment used, greater level of mixing, lower hydration dough = Less bulk required.
Less or no pre-ferment used, minimal mixing, higher hydration = More bulk required.
Jim, IMO, like many things involved in baking bread, it will probably vary based on the type of flour you use, your recipe, and your methods. IIRC, when Jim sponsored a bake off of baguettes, we have enough users doing the same recipe over and over, that a 30% increase in volume during BF was optimum. Of course, for a different bread, or a different type of flour , it may be different. I find that with the 100% home milled hard white wheat that I use, 70 to 90% increase in volume works great for my standard loaf. To find out the answer, I think you need to stick to one recipe, take lots of notes, and try small variations in BF rise ( I use a straight sided container with marks on the side ) and then try to make sure your FP is identical for each one in terms of volume, so see what works best.
PS, don't fall into the trap that you FP each loaf for x minutes at Y temp . If you stop BF at 30 % and do a 1 hr FP , you will likely get a different amount of increase in FP than if you stop BF at 100% , and FP for 1 hour. That is a factor that makes it so hard to do apples to apples.
Thanks Barry. After many failures, I've started to use time as a construct, as opposed to a rule and become more reliant upon the temperature of the dough and the attributes of the dough at the suggested end time for BF. I haven't done a FP on the bench after a BF as time is very limited for me, so I am often using a cold retard to allow the dough to fit whatever time I have for that bake.
Thanks. I'm curious to see if anyone has anything to say about the effect of temperature. The typical rules seem to make sense. In the winter, I'm using a 20% or greater pre-ferment and 70-80% hydration, depending on the product.
i don’t try to manipulate dough temperature at mixing and rarely do for bulk fermentation, so ambient temperature dictates the temp of the dough for me and it ranges from high-50’s/mid-60’s (night/day) in winter to mid-60’s/high-70’s in peak summer.
but: your question was about percent rise in bulk ferment. i aim for the same rise/dough behavior regardless of the temp, and so my bulks just take much longer in the colder months. i think adjusting the amount of pre-ferment is a perfectly sensible alternative.
great original question, btw. i’ve been thinking lately about how a longer final proof (and therefore shorter bulk) would affect crumb structure. i think what mwilson said above is spot-on: one needs to bulk for long enough to get good gluten structure (and how long/what percent rise that is depends on a lot of other factors, such as hydration and how the dough is mixed and handled).
i also agree with barry that baking the same recipe over and over is very instructive. (i think i did the same 20% whole-wheat sd boule for about a year before i tried anything else — except pizza which i used the same formula for.)
hope that helps!
So the bulk fermentation as well as the final proof are somewhat of a dance - you want to have strong gluten, allow bacteria to do their thing and create flavor as well as volume, which degrades gluten. You can think of this as one long process from bulk to oven, and you are simply doing things in between to steer the dough in various directions.
Therefore, the shaping step is somewhat arbitrary and decided upon by different recipes based on different goals.
The shaping step is one where you are suddenly adding a lot of tension to the dough but you also want it to continue fermenting a bit after that (the final proof) in order to get some additional structure.
Depending on goals, you may want to do the final shaping earlier or later in the process.
For example, if you are fermenting at warmer temps, after you shape, the dough will rise faster, so they may have you shape earlier in the process (meaning, smaller % rise) to account for that
Or, if the recipe is shooting for some sort of specific crumb structure it may also have you do a longer/shorter final proof.
Personally I tend to rely on the bulk-o-matic system developed by Tom @ Sourdough Journey. It has a whole bunch of factors you can use to judge if you're ready to shape. This is for the Tartine-type sourdough recipe, and he ferments at a relatively warm temp. That's why his rise % is lower than many other recipes that call for a doubling or tripling. But since there are a lot of other factors you can use to judge, the % rise becomes less important and if it's not quite where you think it should be but the other factors are, you should be OK
Thanks for the link to the bulk o matic - looks like I will need to study it.
Yes if you have 10hrs he has a series of videos on it ;). His videos are pretty lengthy and require a lot of patience. But it's good info.
That site is fantastic and I've watched Tom's videos and used his materials often. It shifted my mindset towards not using time as a reliable factor for the entire process. What I'm getting here is the ultimate answer/non-answer: it depends. I suppose it will really be more process than a formula as a reliable indicator. I appreciate the thoughtful responses.
Jim, I just did two bakes in the last few days, sorry I didn't take photos of the first - it was beyond awful - it resembled a moon crater - there was some rise around the outer edges, the middle was completely collapsed and beyond dense. ( I did FP in a banneton seam side down, so it baked seam side up) BF was about 120% and FP was probably over 100%. ( BF was overproofed because I was sleeping ) Tonights on the other hand is a thing of beauty ( I would only have posted a photo if I had taken a photo of the failure ) same exact formula, BF was around 100% and FP was probably around 80% . FP was in a banneton seam side up as I normally do. As you noted, it is a lot of trial and error - and sometimes luck in getting it to rise the corr0ect amount while you are around to see it.