Understanding bulk fermentation is essential, especially when it comes to sourdough baking. If you're a new baker and not quite familiar with the term, then you're in luck! Proper bulk fermentation can help achieve the perfect airy crumb, and if that's what you want, then stick to the super easy guide.
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What is bulk fermentation?
Mass fermentation refers to the first resting period of the dough after mixing, dividing and shaping. Bulk fermentation occurs at the end of mixing and will last until the dough is separated and preformed. The importance of bulk fermentation is quite significant because it helps develop the gluten strands, strengthening them so that they remain intact after the dough is placed in the oven.
Bulk fermentation can take anywhere from 3-7 hours depending on the temperature of your dough. During this stage, you should pay attention to the dough. This is because you can risk over or under proofing your dough.
A dough that is over-proofed will collapse, deeming any chance of it being baked to perfection for naught. A raw sourdough will continue to rise once the crust is set, resulting in a flaky crust, which isn't great at all.
Why is mass fermentation important?
The importance of bulk fermentation relies on the gases collected thanks to the sufficient network of gluten in the dough.
The gluten network traps gases like carbon dioxide, which in turn causes the dough to rise and double in size, which also happens after the dough is put in the oven.
Can you skip bulk fermentation?
Absolutely not!
If your dough doesn't sit during bulk fermentation, it simply won't rise. This results in a flat dough with no structure, flavor or crust to impress.
Bulk fermentation is where amazing things happen to your dough. During bulk fermentation, the yeasts begin to bloom and the yeasts work together to make your dough rise.
Skipping bulk fermentation will not result in any rise or volume, resulting in sourdough bread with an uneven crumb and rubber interior.
Keep in mind that mass fermentation must be completed. Otherwise, you can even forget about putting your dough in the oven, as the results will be very disappointing!
What to do during mass fermentation
During bulk fermentation, you will need to perform six sets of stretches and folds on your dough, at 30-minute intervals.
The first 4 sets should be done aggressively, you don't want to be at all gentle with your dough. Stretching and folding your dough is extremely important as it helps to strengthen the dough so that there is no risk of the gluten strands separating at any stage. In addition, these kits allow you to adjust the temperature of your dough. While bulk fermentation takes some time, it allows us to constantly force some force into the dough without letting it rest continuously.
Stretch and fold
There are many ways to perform a standard stretch and fold, and it all depends on what works for you.
Some of the techniques chosen are best for the specific shape of your bowl and what works best when you roll the bowl into each stretch and fold.
Moreover, it all depends on the initial strength of your dough. If the dough is quite weak and weak, then you will need to be as strong and aggressive with it as possible.
However, if the dough is quite stiff, then gentle stretching and folding is preferred.
It may help to have a small bowl of water next to you so that your hands and fingers don't get stuck in the dough and break its texture. Use slightly damp hands to lift the dough, then stretch it up and fold it to one side. Then rotate the bowl 180 degrees so you are looking at the opposite side and repeat the above.
You should leave a tube-shaped dough. Then turn the bowl 90 degrees and roll out the dough once more. Finally, rotate the bowl 180 degrees and perform the final stretch and fold. You should have a clean envelope shaped dough in your bowl.
Cover the dough with a kitchen towel or plastic wrap and set the alarm for 30 minutes.
Adjusting the temperature of the dough
The bulk fermentation temperature will determine how long your dough will take to bulk ferment. It's all part of the baking process and the more you know, the better your dough and sourdough bread will be.
Your dough temperature is divided into two separate entities, Final Dough Temperature (FDT) and desired dough temperature (DDT).
Each ingredient used in your sourdough bread recipe has a unique temperature. While much of this cannot be controlled, we can manipulate our results with a splash of warm water to adjust the temperature.
Simple tweaks like this will allow us to change the dough's FDT. Realistically, a constant dough temperature will help you get through the bulk fermentation stage, in the sense that it can determine how long your dough needs to ferment before it's time to bake the sourdough bread.
For baking sourdough bread with natural yeast, you will need a DDT of 75 degrees Fahrenheit to 82 F.
However, if you are working with whole wheat flour or any type of grain, then you should aim for an FDT of 75 degrees F, as the yeast and bacteria will be very active.
Consider the following table for reference:
| Final dough temperature | Estimated duration of mass fermentation |
| 75 degrees F | 4-4.5 hours |
| 78 degrees F | 4 hours |
| 80 degrees F | 3-3.5 hours |
How long does bulk fermentation take?
Touching on our previous point, the duration of mass fermentation will also be extended rely on the temperature of the dough.
Typically, mass fermentation can take as little as 3 hours or up to 7 hours in total.
For overnight bakers, you may prefer to let your dough ferment in the refrigerator to slow down the fermentation enough that it's ready for you in the morning.
How to tell when mass fermentation is complete
It is essential to understand that your dough has finished mass fermentation.
One way to tell is by gently shaking the batter bowl. If the dough looks like it has gassed enough to almost double in volume, then you can safely assume it has finished bulk fermentation.
Here are some other ways to show that your dough has finished proofing.
Signs Your Dough Has Finished Proofing
One of the best ways to judge whether your dough has finished proofing is by removing a small piece of dough before fermenting it in bulk and putting it in a small glass. You can easily judge the status of your dough by checking if the small portion of dough in the cup has doubled in size. Likewise, your sourdough should have too doubled in its vessel.
Another sign that your dough has finished proofing is revealed by gently pressing your fingertip into the top of the dough. If the dough springs back quickly, then your dough has not finished proofing. However, if the dough turns slowlythen this means that the dough is too resistant.
Dough that rises slowly, with a small indentation where your finger was, means your bread dough is ready for the oven.
If your dough is under proof or over proof: What to do
Whether you've encountered the disaster of raw or excess dough, there's no reason to panic. Of course, there are methods that will help fix this.
Under the proven dough
Under the resisted dough can be fixed with extra rest time. Simply let the dough rest for as long as you deem appropriate before final shaping.
On proven dough
To fix over-risen dough, simply remove the dough from its container and gently but firmly press the dough to degas it. Once the dough is free of air bubbles, you can manage to reshape the dough. Then place the reshaped dough back into its container and let it proof once more.
Always keep a close eye on your dough, as sometimes too much insulation can lead to disaster. You don't want your dough to expand so much that it bursts!
When mass fermentation actually begins
We first mentioned that bulk fermentation begins after mixing and forming the dough. Bulk fermentation is simply known as the next step in the sourdough baking process.
Truth be told, though, bulk fermentation actually begins the moment you combine the starter sourdough with flour and water. This means that you start mixing the dough as soon as you have gathered the ingredients.
Bulk fermentation sourdough
Bulk fermentation is an essential step in sourdough baking. Without it, your sourdough bread won't have that unique texture, perfect crumb, and incredibly soft texture.
Understanding bulk fermentation will help you bake perfect sourdough loaves every time!
If you want a reset on your baking, here's mine sour cream for beginners step by step.
Bulk Fermentation Sourdough – FAQ
How long can I ferment sourdough?
You can bulk ferment your dough for 3 to 7 hours, depending on the temperature of the dough. At 78 degrees Fahrenheit, bulk fermentation usually takes 4-4.5 hours.
How do you know when sourdough mass fermentation is complete?
After your dough has finished bulk fermentation, it should have doubled in size, have a slightly domed surface, a smooth surface with bubbles forming, and feel light and airy.
Can you ferment sourdough too long?
No. It's best to keep an eye on your dough during the last hour of bulk fermentation. If you were to bulk ferment your dough for a long time, you could risk isolating your dough.
How long does it take for sourdough to increase mass fermentation?
Your dough should rise until it doubles in size compared to what it was before the bulk fermentation. Some bakers prefer the sourdough to rise 30-50%, although it should be doubled to ensure you have plenty of bubbles, which will help the dough rise and expand during baking.
