What is the relationship between bulking & proofing times
Can someone help me develop an operative understanding of the effects of "bulk fermentation" time versus "proof" time?
If you want to extend the effects fermentation, how do you decide whether to add that time to the BF versus the post-shaping proofing?
I've probably at least 15 books and I've been baking weekly for 2 years, so I have a basic familiarity, but I've never seen this particular relationship (or ratio) explained in depth. If someone asked me, I would say the the proofing period is what allows alveoli to develop in an evenly distributed manner, after the physical disruptions caused by shaping. But that ultimately, the totality of the crumb ("underproofed" / "overproofed" / etc) depends on the total time from inclusion of the levaning agent to the time it's baked. Is this on track?
First of all - get off the track and go by the dough. It's ready when it's ready (depending on leavining) and then proceed. In a normal cycle - there are 2 rises - then a bake which includes a rise. Call them what you want - you'll see they basically boil down to the same thing - regardless of name.
Under/over - depends on the starter - and time - simple. Using is always up to you - also simple (and a big variable). Personally - I'd say give up the books (and i recommend this to all) and get your hands dirty! You'll figure it out soon enough. Enjoy!
It's a complicated subject without clear-cut answers. But the general ideas are clear enough to get started on. You probably know all this already after two years of baking.
Let's start with the end state - proofing. I have measured the rate at which dough volume increases with time. I have noticed that after the dough has been rising for some time and then worked with - folded and deflated for dough, stirred for starter or biga - it will immediately start to rise faster than before. So whatever criteria you judge it by, you can expect proofing to take less time than bulk. You can see this effect at work in many of the breads posted about on this site. Bulk times may vary from say 5hrs to 8 hrs to 14 hrs or even more. Yet proofing times usually stay in a narrower range: 1 - 2 hours for the most part.
Other activities contribute to faster proof times. For example, if the bulk time was long because the amount of leavening was small, it takes some time for the concentration of yeast to build up to what it would have been starting out with with more leavening. Once the concentration has gotten to that point, the rest of the bulk fermentation will tend to happen at a similar rate. There is always that initial delay while the yeast and bacteria become active and the initial CO2 dissolves in the dough. Oversimplified, but it gives you the idea.
So proofing will almost always be faster than bulk.
Let's move on to the bulk fermentation stage. What do we want to get out of it? Adequate growth of yeast so that it can generate lots of CO2. Getting as much CO2 as possible dissolved into the dough. Improving the gluten structure, which gets more developed over time, although it relaxes over time too. Developing flavor, which improves with time even for yeasted dough and even more so for sourdoughs.
Why not run bulk fermentation longer? Potential protein or starch attack, using up all the available sugars so the yeast activity starts to stagnate, excessive acidity which will change the flavor and perhaps inhibit the yeast or degrade the protein. And of course schedule convenience plays a role too.
So the duration of the bulk stage will be a compromise between the pros and cons, and those depend on flours, hydration, starter or levain condition, the type of bread being made, the temperature, and on and on. There has to be enough nutrition and active yeast left so that by proofing and then baking time, the loaf will have filled up with nicely with CO2, will have a good internal gluten skeleton to hold its shape against gravity, and the proofed loaf will have enough oomph left to give a good oven spring and brown well.
Baking in a loaf pan or other container that supports the loaf reduces the need for the internal structure and may also reduce the value of good oven spring, depending on your taste and goals for the loaf.
With all these factors in play, and as home bakers we can't really know their properties precisely, experience plays a large part, and it's no wonder people say to "watch the dough, not the clock"!
You asked about "underproofed", "overproofed". Those are very fluid notions, and I personally don't think they have helped me much in my baking. Say a loaf ferments to long that its protein weakens, the dough starts to collapse, and the loaf never browns up. Well, yes, I would say that loaf was overproofed. That extreme hardly ever happens. Say the loaf comes out dense and gummy. It *may* have been underproofed, but it may have been too wet, baked at too low a temperature, or for too short time. Or some combination. Or the flour was unable to hold up over time at that hydration. See? it's not that clear-cut.
It's lucky for us that baking basic bread, especially with wheat flour, is pretty forgiving. Take any basic recipe with a moderate hydration and a preponderance of good quality white flour, almost any reasonable percentage of starter or levain from say 15% and up, and you will most likely be able to make a good or very good loaf. I'm sure this claim matches up with your experience.
TomP
It might be easier to differentiate between the bulk ferment, and what's it's for, and the final proof.
Sure, you can shape straight away but then you'll have to bake it when it reaches that optimal height for a good oven spring but the yeast and bacteria will probably not have proliferated the dough enough to get the best benefits coming from the fermentation. Mainly a more complex taste. An optimal time for good oven spring may be just under doubled but the dough will have enough food for it to triple or sometimes more. Hence the two stages.
Once the dough has been shaped then you are on a stricter timescale where one has to be careful to not allow it to rise too much. How do we prevent this from happening? Introduce a bulk ferment, knock back then shape and allow it to rise again.
If you don't do anything in the fridge, start to finish at room temperature, then it's definitely better to add it onto the bulk. As long as you don't overdo it. There's a difference between over fermentation (all the food has been consumed) and over proofing (the dough has risen beyond the optimal level for good oven spring). If one has over proofed and it hasn't over fermented then one can shape it for a second time and let it rise again. I think the confusion arises because fermentation happens in both stages, but the reasons for the stages do differ, and something that has over fermented has naturally over proofed but not necessarily vice versa.
If you wish to extend the ferment in the fridge then it can be done at either stage. I also think the fridge is just for convenience. It means you don't have watch the dough as much.
Is having a good oven spring really the goal? I don't think so. A goodly number of my bakes proof just fine but have little oven spring.
Oven spring is caused by a slow penetration of heat toward the middle of the loaf. Baking in a pan almost always results in less oven spring (better conductive heat transfer). That doesn't mean they're failures.
Is a different story. Nevertheless the purpose of a final proof doesn't change. While a bread pan is more forgiving it can still be under or over proofed. At the end of the day if the bread gets eaten up and enjoyed it is a success.
There's a trade-off here, isn't there? I think if one wants a good volume of the finished loaf, a strong oven spring isn't necessary. If one wants the scores to burst wide open and possibly produce crispy ears, then there needs to be good oven spring. It's mostly about what kind of result one's after.
TomP
The purpose of the final proof is to end up with the oven spring one is after! but the purpose is the same. If one wants it to rise more or less, this is aimed for in the final proof, the end result would be a 'good' [optimal] oven spring.
When I do a bread pan loaf i'll final proof for longer than a free standing dough because the results I want differ.
Thank you, guys. I'm reading and re-reading this.
Seems to me that both the BF and proofing are times where fermentation occurs, CO2 is created/absorbed, and the scoby is developing, etc. There's not really a difference in the biological process -- just a continuation, right?
My understanding and personal observation in my kitchen is also that the fermentation occurs on an exponential curve. And it seems to me that the bench rest and shaping is "just" an interruption on that upward curve, which redistributes the CO2 and makes the aveoli re-form within the shape that the baker creates. As we handle the BF'ed dough, it releases and redistributes the alveoli into our chosen shape. But the number of bacteria and yeast remains unchanged by the shaping and they just keep feeding and growing.
Here's another way to ask the question. If BF is 5 hours and proofing (+bench rest & shaping) is 2 hours, the total time from mix to bake (let's leave out retarding) is 7 hours. What would be the difference between moving the "moment of shaping" earlier or later, making it 4 hours BF + 3 hours proofing. Or 6 hours BF and 1 hour proofing. Know what I mean?
Davey, I think I understand what you're saying about "Luke, turn off your targeting computer...." So what kind of criteria are you looking for to end BF?
Honestly, the "rate of rebound" in the finger-poke test, the texture of the dough, the doming, the "jiggle" are all extremely subjective! I'm trying to identify sign-posts which can increase my consistency.
Sorry if this is not clear!
Maybe I just need to run some experiments to see for myself....
Not a complete answer, but think about what you have seen during a bulk ferment. The dough relaxes, right? If the hydration is higher, it relaxes quite a bit. In the bulk ferment tub, the dough tends to level off.
Suppose you could count on that seven hour total fermentation being the right time, and shape the loaf after say two hours. By the time your seven hours rolls around, the loaf will most likely have flattened out like a lizard. Yes, it will rise and inflate some during baking but it's still likely to end up fairly flat. Someone should check this by trying it, though, because glass bread inflates an amazing amount during baking. But then, it has a *lot* of water to create water vapor and help the rise.
If it's going to be a pan loaf, this will not be a problem, and you can bake some fine pan breads with gloppy dough and only the bulk ferment. Just put the mixed and kneaded dough into the loaf pan whenever you like.
How about the other extreme? Bulk ferment for 6.5 hours, then shape, and proof for 1/2 hour. Unless the hydration is fairly low the dough will be very relaxed and you will likely need to really work with it to get the dough to hold a loaf shape. With a very short proof, the loaf may not have time to refill with gas before it's baked. Again, it would be interesting for someone to actually try out this extreme. I've thought about doing it from time to time but was too lazy to actually do it.
Unless you have a very repeatable process, including the temperature, one trouble with going to these extremes would be that you won't be able to tell if the dough is developing on schedule. Maybe today it would have needed 9 hours but it only got the same seven.
In the middle, though, as I wrote earlier, wheat breads are very forgiving and I think you can mix and match and still produce a fine loaf.
TomP
I wrote
All right, I tried this out today. I put together a bread that I've been making for a while, and it's been fairly consistent. The bread uses 25% atta flour, sometimes durum atta, sometimes whole wheat atta. The rest of the flour is Gold Medal unbleached all purpose. Sourdough starter is 30% and hydration is right about 70% give or take a few percent. Bulk ferment time is usually 6 -7 hours. Then a preshape, 15 minutes rest, and then shape and proof which has been 1 - 1 1/4 hour. I've also been including some nigella seeds, which add a pleasant perfume to the bread.
For today's variation I shortened the bulk ferment to 3 hours. I'm not sure if it had even begun to visibly rise or not but if it had it wasn't much. I extended the proof to 3 hours, which was 2.5 - 3 times the time I have been proofing these breads for. The loaf proofed free-standing on parchment paper, covered by plastic wrap. As I expected, the loaf flattened out but not as much as I had feared. I ended the proof because a few mild depressions were forming near the top. I was concerned that they might be signs of weakening. More likely they were just signs of imperfect shaping and I could have proofed longer.
I did change the baking schedule a little. My electric oven setup has a cast iron pan filled with rocks on the bottom shelf. A baking steel sits on the middle shelf and I slide the bread on its parchment paper right onto the steel. Then I throw 1 1/2 cups of water onto the rocks and seal up the oven vents as best I can. For this bake, I wanted to give it the best chance to rise in case the long proof had left it without enough oomph. So, get this, after generating the steam I turned the oven setting down to 250 deg F/121C and left it there for 20 minutes. The idea was to delay the setting of the crust as long as possible by keeping the temperature low. Then I returned the setting to 415 deg F/213C for another 20 minutes.
By that time the loaf was baked beautifully. It also expanded well and ended up with a very good volume. In first picture below I compare this loaf with the one I baked a few days ago, using the same kind of dough but a more normal division between bulk and proof. Today's loaf is clearly larger than the older one even though they both used 300g of flour. Today's loaf is to the left, behind the older, smaller loaf. You can see that the loaf that had a short proof opened up its scores much more and produced some nice ears, which today's loaf did not.
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Oh, fascinating! This is exactly the type of question that I had in mind!! Really appreciate you sharing the experiment. I don't know that flour, but I'm so surprised you achieved a bigger loaf with that proofing time. I don't think I have quite a wide pallet of oven technique to make the adjustments/compensations you described; it's a good reminder that it's all linked together.
Gold Medal is a standard nation-wide brand in the US. Pillsbury is another, and I think their unbleached all purpose flour acts just the same. Both have a little lower protein than King Arthur's all purpose, but they all seem to perform the same for me.
GM unbleached has been on sale in the stores lately so I bought a couple packs. I give it a "meh" rating. It is well-behaved but bland tasting, compared to our local miller's offering. I'lll use it up in 50/50 blends.
The blandness - I haven't noticed a systematic difference in flavor when I use King Arthur's AP, but then the product is highly standardized for consistent performance so it can hardly be anything other than mild tasting, I think.Also, my taste buds have had many, many years of service so maybe I'm not the best judge.
[Later - edited to remove any implied snarkiness, which was not my intent]
Using sourdough naturally brings out more flavor in these flours than straight yeast would; otherwise making an enriched dough can make up for blandness to a degree.
Ah, yes, I'm in the States, so familiar with the usual supermarket offerings. I just meant I don't know atta flour. And I see now that the loaf is mostly the white!
These loaves used 25% atta flour. Atta flour is used in India to make rotis and similar flatbreads. The ones I have tried were ground from whole wheat. One always reads that a characteristic of atta flour is that it has a very high percentage of damaged starch. This supposedly makes it a bad choice for making bread but I have been having very good results at 50% and even up to 80% atta flour. Another characteristic is that the bran is very finely ground. In two brands I have tried, almost all the bran would pass through a #50 screen. This is very different from stone ground whole wheats that I know, where a #30 screen will remove much of it..
I find that adding the atta flour improves the flavor of the bread and the doughs have good handling properties. I prefer some brands made from wheat and imported from India over brands made from Canadian durum. Both are good, though.
Any Indian or "international" store should have atta flours, though sometimes only in sacks larger than I want to buy.
More out of idle curiosity than anything else, but is your Atta milled in India or in the USA/Canada (e.g. Golden Temple) - there's quite a big difference in the protein difference. It isn't clear from your comment about durum wheat either - from what I knew my atta was made from soft wheat.
I used to be a fan (of the Indian, "Sharbati") type but then Modi restricted exports of wheat and we had old stocks for a bit which put me off it. And it isn't like I'm trying to make flatbreads, most of the time. The Sharbati ones would really soak up the water well, from what I recall, the breads were okay but I always thought I could achieve more with the flour than I managed.
-Jon
I have a sack of sharbati, apparently milled in India, that I bought earlier this year.Before that, I bought a sack of sharbati, a different brand, that seemed to be from India but looking more closely at the packaging had been milled in Egypt for General Mills India. I also can get Golden Temple milled from durum wheat. I prefer the two Indian sharbati flours over the Golden Temple. I think they add a flavor more to my liking, and I think they work better for making rotis. Note that I am very unskilled at making roti...
It may be standardized but it's still "meh" in my experience. I keep notes and photos of all my bakes, and my impression was the same last time I tried it.
Better options are available to me, at equal or less cost. So why take on any "burden"...
I don't know of any better flours I can get here. It would take me an hour and a half drive one way to find better ones and I don't want to do that for day-in, day-out baking. I do mail-order flour to try but as you know that gets pretty expensive quickly. For stone-ground flours I'm in good shape because of the local water mill.
From the moment the starter goes into the dough till it is baked. However the different stages have different purposes.
If the starter goes in from the initial mix but you hold back on salt for the first 30 minutes to 1 hour then the purpose is an autolyse.
If there is a period of rest between the addition of salt and shaping then the purpose if a bulk ferment. This is to give the yeast, and bacteria, to proliferate the dough.
The rest after shaping is the final proofing. This is to allow the dough to rise again for as much oven spring as needed.
Yes, the fermentation has an exponential curve as yeasts multiply and each one of those yeasts multiply. That's why it is slow at first and speeds up.
When to shape depends on a few factors. You need to look at flavour. Once a bread has risen a certain amount it would be the optimal time to bake for the purpose of structure and oven spring but doesn't necessarily mean it has had optimal fermentation. This is why one may bulk till more than doubled but then shape and allow to rise again till just under doubled. If one shapes the dough straight away then it would be going in the oven earlier so affecting the flavour.
One must also look at crumb structure. The less a dough is handled earlier on in the fermentation process will encourage a more open crumb. De-gas and shape later on in the fermentation process so it has less time to rest before going into the oven might encourage a less open crumb. But then again one must also look at flour, hydration and how it has been handled through the bulk and shaping stages.
Experiment and see which results you prefer.
So Tom, this tracks with my understanding. And I guess I'm wondering what happens if I try to retard my BF to let the flavor develop a bit, but catch it at a 1.25x rise point, and then extend my proofing time for gassing up.
Abe, you said "This is why one may bulk till more than doubled but then shape and allow to rise again till just under doubled." HOL' UP. You are able to double your BF and then double your proofing volume? With whole wheat? I never come close to this and my bread would be completely exhausted/flattened if I tried. When I get a 2x rise during BF, it leaves extremely little potential for further gas development during proofing -- and maybe weakens my structure, too.
What are your indices for ending BF? Size / time? Doming, texture, jiggliness?
And where do you usually stop your BF, for a mostly whole wheat boule?
Here's a 100% stone-ground whole wheat loaf I baked that used an overnight bulk retardation. I sifted out the bran and scalded it. My notes don't say but I remember treating it much like any other dough: I put it into the fridge about an hour before I think it will have doubled. Then it will likely have doubled or more by the next morning. I'm sure that was the case this time.
This dough had a fairly high hydration and needed a lot of stretching and rolling to develop the strength to hold its shape during proof. The proof was unusually slow - it took four hours - and the loaf had flattened out more than I wanted. I didn't think it seemed exhausted, though, and it popped up well in the oven as you can see:
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It is true that the scores didn't open much but I think this came out to be a fine loaf of bread.
I don't think it's hard and fast. Of course, by now I have some general idea of what to expect. and I have confidence that for most of my breads, smallish variations one way or another won't be a problem.
Now that I'm using a semi-transparent tub for most of my bulk ferments, I go mostly by a combination of size and the openness of the structure I see through the sides. I don't think it's possible to be very precise about doubling. When the dough is put in after kneading or a S&F session, it will typically be very tight and domed. With my small 300g of flour loaves the mass of dough may not even reach the sides of the tub. Hours later the top may be very flat. Later it may be somewhat domed. So I go by a general impression of doubling (or even more for many doughs), and more by the airy structure I can see through the sides.
For proofing, in addition to the visual size - and who can be precise about the volume of a free-standing loaf? - there can be some intangible aspect of the appearance that lets me know if I think the proof has gone on long enough. I don't find the poke test reliable. It is somewhat like knowing if the linguini is done yet. There's a certain soft, plumped appearance that the pasta strands start to show. If they don't have that look they aren't done no matter what the clock says. If they do, they are ready or almost ready. Once you can recognize the look, you don't have to keep biting the pasta over and over. For bread, especially predominately white wheat flour doughs, there's a certain something about the appearance. It has something to do with a sense of tension, and how softly the dough follows small contour changes, and sometimes something about the dullness of the surface. I can't really articulate this well, but it's there to be seen.
Keep in mind that almost all my loaves get risen free-standing and so the entire surface is on display. If the loaf is proofed in a loaf pan or banneton, these signs are harder to discern. My eye isn't as well trained in these cases.
Very helpful - thank you!
it depends on flour and hydration. Lot's of things will determine how much one bulk ferments for including flavour of end product. But in all wheat breads, however much it is capable of rising, the final proof has a stricter optimal time and rising than the bulk ferment for this is when you're aiming for structure while baking.
However, as a rule of thumb for the bulk ferment, you can't go wrong once it looks puffy and aerated.