Bulk times & volume increase
I'm a (moderately) longtime reader of this forum (2 years or so), but an infrequent poster.
I have two puzzles that I think may be related, and I was wondering if the community had any thoughts on them.
(1) My sourdoughs often take much longer in bulk than other people say.
(2) When I allow the dough to rise to what looks like about 30% (hard to judge in a bowl, and I do not have a straight-sided container of the right size) during bulk, it usually ends up underproofed. However, 30% is a common recommendation for wetter doughs.
An example of (1): I made Trevor's Champlain at 72% hydration last weekend. Trevor says that the loaf should take 4--6 hours, but I left mine out for 7, then put it in the fridge overnight, then left it on the counter for 8 hours the next day. The crumb did not come out badly, but the bulking time was way longer than recommended. Since it was warm, the kitchen was between 75--80F during the time when the loaf was rising. It likely took some time to warm up when I took it out of the fridge, but it probably still rose for around 11 hours with the dough at room temperature and showed no signs of overproofing.
I thought that (1) might be related to starter activity, but when I made the Champlain, my starter tripled in about 5 hours at 80F.
I have a couple of suspicions about (2):
First, my fridge temperature varies a lot from the door to the back of the fridge, so I usually try to place loaves near the front where it is warmest. They never show much expansion after proofing in the fridge for 14--18 hours, but that seems normal based on what I have seen elsewhere, but perhaps my fridge is colder than most people's. I will have to take its temperature and see. In the meantime, what are people's fridge temperatures?
Second, perhaps other people fold more than me. I don't think this is the case, but I bring it up because there was a video (I tried to find it again and cannot) that I saw demonstrating how an unfolded dough had doubled by the end of bulk, while the same dough increased by only about 50% over the same time period if it was given folds. Hence, if I folded less than other people, then a 30% rise could occur without bulk being complete.
Does anyone else find 30% inadequate or have experience with similar issues?
Thanks
BF @ 75-80F should ferment a lot faster. My first guess is your starter.
Tell us everything you can about it.
How did your Champlain turn out with the starter that tripled in 5 hours at 80F.
Dan
The Champlain was the same one that took 11 hours to bulk, and it turned out well---I don't have photos, but the crumb was quite nice, and the acidity was present, but surprisingly mild given the long bulk time.
I store my starter in the fridge. I usually take it out Wednesday or Thursday and keep it warm (75--80F), feeding it twice per day at a ratio of 1:3:3 starter:flour:water with a 50/50 mix of whole wheat and white flour.
On bake day, I feed it 1:1:1 and wait until it looks very light and bubbly before using.
One factor that may have contributed to the long rise is that the Champlain calls for only 50g levain for 450g flour. I would normally use about 100g for that quantity of flour. However, the growth of the organisms in the starter is exponential, so I would not expect using half the starter to come anywhere near doubling the bulk time.
Kristen of fullproofbaking has a nice series of pictures showing dough rise during bulk fermentation:
https://www.instagram.com/fullproofbaking/p/BphIt9MHy2t/?utm_source=ig_share_sheet&igshid=1ddvjxikho1pm
One of the points of her post is that is hard to tell how much the dough grows during bulk. She did a fine job, in that she put dough in glass jars so that we can compare.
Thanks. Perhaps if I take a little bit of dough and let it rise in something narrow at the same time as the main dough, I can use that to guage the rise.
If you normally use 100g starter to achieve a certain result, and in this case you're using half that amount, it would seem most logical that it would take 2 times as long to achieve that same result. As your starter is not Trevors (I think that was the creator of the recipe you used), I would not expect the same results, and that's only 1 variable. I'll make note of an oft quoted adage I used to hear a while back - watch the dough, not the clock. Seems to me things are normal - for your particular variables. Good luck!
If we approximate the starter growth by an exponential model, its population is given by p(t) = p(0)exp(a t), where p(0) is the initial population and a a growth constant, associated with the particular starter culture.
The time T it takes for the population to double (doubling time) is given by T=ln(2)/a. Notice that it is *not* proportional to the initial population. So if you start with half the population of starter, you should wait ln(2)/a until it reaches your usual population. From then on, things should proceed approximately as before (not exactly, since fermentation had already kicked in T time units ago, but let's not be that picky).
The hard thing to gauge here is how many times our initial starter doubles its population until we bake the dough. If you are thinking about measuring this in dough volume, let me remind you that manipulating the dough during bulk makes this increase much smaller than if you do not (Kristen of @fullproofbakin illustrates this beautifully in her pictures about bulking). Not only that, it is not so clear how the increase in volume due to gas production correlates with the actual starter population. Sure it increases with increasing population, but as Kristen's pictures also show, volume increase occurs almost 'all at once' in the final hours before it starts to collapse. So, it is a hard thing to predict.
I started a culture in Nov. 2018. The first decent loaves I got bulked for almost 7h. Only after I laced my starter with an older one (3 years+), did things start to change. Now I bulk 4-5h and have been getting consistent results. I live in Rio, Brazil, so my room temperature is usually in the upper 80's-90s. I try to keep my dough under 28C, which is about 80F.
People say 'watch the dough', '30% increase in volume', but these are hard things to do. I would recommend keeping track of time as well. If your conditions don't vary much, it is the easiest variable. As long as you know what to expect when you switch things around (whole grain, higher hydration implies faster fermentation and so on), you should be fine.
It would help if you posted some pictures, so we can judge better what you're talking about (maybe your loaves are better than mine and I should be the one getting advice from you).