The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

How much rise during bulk fermentation?

yoboseyo's picture

How much rise during bulk fermentation?

I'm troubleshooting an issue with my sourdough, and I'm trying to isolate it to each stage. Doing by times called for in a recipe is pointless because of temperature differences, amount of starter, activeness of starter and type of flour. I can roughly tell when the final proof is done by the poke test. But I don't know how long the bulk fermentation should go for and how long the period for stretch and folds should be. I have heard of rule of thumb to let it double in size, and I think that might be too much because it should at least double in size after the final proof. Is there anything I should look out for to know how long to bulk ferment for? Number of bubbles, etc?

Mini Oven's picture
Mini Oven

Right and part reversed.  The bulk ferment is very important for several reasons and often this is cut too short.  One needs to let the yeast multiply and populate the dough in order to raise it later on.  The final proof usually comes out better, especially with sourdoughs, when the volume is not allowed to double before baking.  That's the general rule of thumb.  Let the oven raise that final portion to "double."  Save some rising for the oven where the heat can set the crust.

Recipes can vary in instructions and add retarding or cool fermenting, lengthen or shorten final proofing time, and some flours don't like to wait too long to be baked after they are shaped (they prefer to fall apart instead.)  The answer your answer depends on the type of dough and flours in the dough. So let's take a general sourdough loaf.

Sourdoughs generally benefit from folding the dough as it bulk proofs to strengthen the way it holds itself together while the bacteria in the dough is busy trying to relax the dough at the same time.  That is the main difference between sourdoughs and yeasted doughs.  Maybe it helps to look at the bulk ferment in this way....  think of sourdough fermenting as one total fermenting time from mixing up the dough to baking with a lot of breaks in between eventually getting the loaf the way you want it and then bake the sucker before it falls apart.  

Compare this to a yeasted dough that has clearer lines between bulk rise, shaping and final rise.

It helped me a lot in the beginning to not retard the sourdough and to shape the dough after every folding while it ferments.  To get the basic timing down, mix up your dough, let it sit and hydrate for half an hour then knead it ( perhaps add the salt)  to make sure everything is mixed in well and all the dry flour is incorporated.  Shape into a ball with or without checking for a windowpane and cover with a large see-thru bowl right there on the work bench. Take a picture from the side.   Watch it ferment and rise.  Patience.  If you see your dough rising generally more "out" than "up" remove the bowl, give it some folds to tighten up the dough surface, tuck under the corners sticking out and pretty much return the shape back into a nice roundish loaf.  Cover and record the time.  Wait again. 

What you will be able to do is feel the dough building gas pockets inside the dough each time you touch it. Feel the differences more and more each time you uncover the spreading dough to fold and return it back into a loaf shape. Just keep doing this as the loaf gets bigger and rising goes faster.  You may notice patterns... rise up, rise sideways, uncover, fold gently, reshape, dough feels tighter then looser, stickier, aromas increase, etc.  sooner or later you will notice you are reshaping every hour, every 45 min (high time to turn on the oven) and when you get the feeling it won't hold its shape for 30 minutes after shaping park it onto parchment instead, score it and place it into the hot oven.   That is why folding followed by shaping can give you a certain edge.  Not a bad habit to get into especially in the beginnng.  Anytime you want to bake it instead of folding it, you can pop it into the oven. 

Once you understand the timing of that particular dough, you should be able to figure out about the right time to let the dough do its last rise in a banneton for the final rise/proof.  Resting in the banneton helps the dough skin dry out a little bit and become a memory and a container to help the dough maintain its shape in the oven while the heat expands the gas bubbles and sets it into a loaf.  Important is to have the right sized banneton for the amount of dough and to not overproof in the banneton.  The dough should be set in and touch part way up the sides immediately. If not, the banneton is too big, a flatter loaf will result.  If the dough fills the banneton immediately, it is too small, a larger one is needed.  Don't let dough spill over the edge of the banneton. If you see your dough changing from nicely domed to getting those flattish edges (take a look at a fried egg) then it has proofed too long in the banneton.  It should have increased in volume a bit but still be (for want of a better word) perky when you gently tip it out. 

yoboseyo's picture

Thanks, I think I get you - think of the cold proof in the banneton as the final stretch and fold. So at what point would you put it in the banneton? 1 hour between shapings?

UpsideDan's picture

There are many correct, and very different, answers to your question. I like to look at the bulk and proof as one fermentation process and not as two separate ones. If you look at the micro level, yeast is introduced into the dough and start multiplying and producing gas. Due to the multiplication, the amount of gas produced at the beginning of fermentation is much smaller than, say, 4 hours later. From the point of view of the yeast, there is no difference between “bulk” and “proof”, it is just eating and producing gas. There is more yeast activity during proof because it comes after the bulk so you should expect much faster changes.

The “structure of the dough” can be achieved with few stretches and folds during the first hour and from my experience there is no need for more. At the same time, the dough is being digested so the structure keeps deteriorating. This limits the total useful bulk + proof time.

The difference between bulk and proof is one – the baker cares about the shape and bubbliness of the dough by the end of the proof, while in general, it does not really matter during bulk AS LONG as the proofing result is achieved. Therefore, you can basically stop the “bulk” after one hour, shape the dough, and call the rest “proofing”. As long as by the end you get the shape and puffiness – you are doing well. Experience shows, however, that most likely the shape will not be properly retained for too many hours.  You therefore want to keep doing the “bulk” stage until the dough is ready for the shorter “proofing” stage.

So when you see a recommendation to double the size of the dough during bulk, it should come with a shorter proof time than for when bulking to only 1.5 in size (for the same type of dough and same temperature). Shorter bulk will, in general, go well with longer proof and vis versa. You have to make these two work together, not to isolate the stages…

It is also very important to understand that the skill level is part of the determination for what is over fermentation during bulk. An experienced baker can still work with a dough that might be totally not manageable for someone with less experience. So with less experience it is better to avoid making the dough too fragile by the end of bulk, and "too fragile" is very personal.

I would say that the rule is - stretch the bulk as much as you can but keep it short enough so the dough is not too fragile for you to work with, and can keep its shape and puffiness by the end of the proof. (with "shape" I include the ability of the dough to survive scoring without collapsing)