- Feb 12

Bulk Fermentation Facts

BULK FERMENTATION or bulk proofing is one of the MOST important steps in sourdough bread making. During the step, the yeast is multiplying in the developed dough, and just like the name suggests, the dough ferments in a large, single mass.

When bulk fermentation is complete, the dough is divided, shaped and proofed again before baking.

Why is bulk fermentation important?

Because it is the proofing stage when the dough is accumulating gases which will determine the structure and flavor of the sourdough bread.

Proper fermentation is crucial in sourdough baking, and even with the best tools, ingredients and experience, if you misjudge bulk fermentation, your dough could turn out over or under proofed.

What’s the best way to control bulk fermentation?

The best way to control it is to keep your dough at a constant temperature throughout bulk fermentation. Sourdough yeast perform best at temperatures between 75-82F.

This can be difficult to control when you live somewhere with fluctuating temperatures and seasons with steaming hot days and cold nights.

Photo: by Yana Zubko

There are a couple of tools that you can use that can help control the temperature:

1) Proofers

2) Bread mats

3) Controlling your hydration- 100% hydration will proof faster than lower hydration dough.

How long does bulk fermentation take?

It varies based on temperature, the recipe you used and the amount of starter. But on average it’s between 4-10+ hours. During summer months, it usually only takes my dough 5 hours to proof, but when it's colder outside (and in my house) it can sometimes take 10+ hours! And you can't always rely on time, go by the look and feel of your dough - use your baker instincts!

Some signs to watch for: