Bulk Fermentation Sourdough, Explained! [Your Easy Guide]

Published Categorized as Beginner Guides

Understanding bulk fermentation is essential, especially when it comes to sourdough baking. If you’re a new baker and aren’t quite familiar with the term, then you’re in luck! Appropriate bulk fermentation can help achieve the perfect airy crumb, and if this is what you want, then stick around for the super easy guide.

Bulk fermentation sourdough explained [easy guide]

Table of Contents

What is Bulk Fermentation?

Bulk fermentation refers to the initial proofing stage that occurs between mixing and dividing or shaping bread dough. Other terms used for describing bulk fermentation include first rise, first proof, bulk rise, or bulk proof.

It is often called bulk fermentation as many bread bakers and bakeries tend to ferment large amounts of bread dough at a time. Home bakers may bake one to two loaves at a time, though the same principle applies.

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

Why is Bulk Fermentation Important?

Bulk fermentation is incredibly important because it is the proofing stage, where the dough is collecting gases that will determine the overall structure and flavor of your sourdough bread. The gluten network developed from mixing will entrap the carbon dioxide produced during bulk fermentation, resulting in a light and airy texture with a fluffy interior.

The large, even holes and soft interior of the sourdough bread are often referred to as an “open crumb.” An open crumb can only be achieved with appropriate bulk fermentation.

Proper fermentation is incredibly important in sourdough baking. Even with the best-measured ingredients, tools, and experience, if you bulk ferment your dough for longer than necessary, you may risk achieving an under or over-proofed dough.

Bulk fermentation sourdough explained [easy guide]

What to do During Bulk Fermentation?

Sourdough bulk fermentation is the longest room-temperature stage in sourdough baking and is also the most difficult stage for most home bakers.

During bulk fermentation, the dough must not be tampered with, as you must allow the dough to ferment on its own. You can try to manipulate the dough through minor adjustments such as proofing your dough in a covered mixing bowl.

Stretch and Fold

Many bakers include stretch and folds or coil folds during bulk fermentation. Performing a series of folds during bulk fermentation will help regulate dough temperature further gluten development, and help you judge how quickly your dough is fermenting.

Whether you choose to stretch and fold or coil fold the dough, both are beneficial for baking sourdough bread. Some bakers prefer one over the other. I like to choose the stretch and fold method, as this creates sufficient surface tension and dough strength.

The amount of folds as well as the length of bulk fermentation time depends on the sourdough recipe. Fewer folds may lead to a slack dough during shaping, which can flatten during the baking process. Too many folds may create a tight crumb structure.

Stick to 6 sets of stretch and folds, allowing 30-minute rests between each set.

Regulate Dough Temperature

The best way to effectively control bulk fermentation is by keeping your dough at a constant temperature throughout bulk fermentation. The sourdough yeasts are at their best when they’re in a slightly warmer than room temperature environment (75-80 degrees F).

Controlling bulk fermentation might be difficult if you live somewhere where the temperatures tend to fluctuate. You can use a thermapen to judge the overall dough temperature, simply stick the thermometer into the dough and it will reveal the temperature of your dough almost immediately.

Lavatools javelin pro duo ambidextrous backlit professional digital instant read meat thermometer for kitchen, food cooking, grill, bbq, smoker, candy, home brewing, coffee, and oil deep frying
Buy on Amazon

How Long Does Bulk Fermentation Last?

Typically, bulk fermentation can last anywhere from 3-7 hours depending on the temperature of the dough, the recipe, and the amount of sourdough starter used.

At 78 degrees Fahrenheit, bulk fermentation lasts up to 4-4.5 hours. If it’s colder or you’re using less sourdough starter then the bulk fermentation may take longer. Cold bulk fermentation is not recommended as the cold temperatures will not proof the dough enough and it will not hold shape. Instead, you can opt to proof the dough in the fridge overnight after shaping.

The time it can take for bulk fermentation to be complete is wide, as there are many factors that can affect how fast or slow your dough ferments. Some of the factors that can impact sourdough bulk fermentation time may include:

  • The strength of your sourdough starter
  • Ambient temperature
  • The types of flour or other ingredients used
  • Humidity

How to Tell When Bulk Fermentation Has Finished?

Knowing when bulk fermentation is complete can be a bit tricky, and with frequent sourdough baking, you will be able to judge when it has finished proofing.

Signs That Your Dough Has Finished Proofing

There are some general signs and indications that relay whether your sourdough has proofed correctly or not. When bulk fermentation is complete your dough should:

  • Have doubled in volume, or just under
  • Have a slightly domed surface, and come away from the edges of the bowl or container
  • Have a smooth surface with bubbles forming, and it shouldn’t be sticky
  • It should feel light and airy
Bulk fermentation

What to do If Your Dough Has Under Proofed or Over Proofed?

Sometimes we can misjudge when bulk fermentation has ended, which can result in under or over-proofed dough. It’s important to learn how much your dough has been proofed and whether it requires more time.

If you’ve moved on to the pre-shaping stage and notice that your dough seems under or over-proofed there are some things you can do to fix it.

Under Proofed Dough

Theoretically, it is much easier to rescue an under-proofed dough rather than an over-proofed dough. This is because under-proofed dough simply requires more time to proof. If your sourdough is not rising during bulk fermentation, then there might be an issue with your sourdough starter. A weak sourdough starter may prevent the dough from rising during bulk fermentation.

If your dough is under-proofed then simply let it rest for longer. Meaning that during pre-shaping or shaping, allow the dough to rest so that the fermentation stage is extended. The dough will continue to proof slowly, and you can also extend it by placing it in the fridge to cold-proof overnight.

If the dough remains under-proofed once you’ve taken it out of the refrigerator, then let it proof at room temperature before you bake sourdough bread.

Over Proofed Dough

An over-proofed dough is more difficult to salvage. If the dough is slightly over-proofed, then simply divide and shape the dough into a banneton and place it in the refrigerator. The cold temperature will slow down fermentation and your bread will most likely end up perfectly fine.

A dough that is extremely over-proofed however, might not be salvageable. If it’s extremely wet and slack that it is near enough impossible to shape, then you might want to ditch the loaf and make focaccia out of it. Drop the dough onto a sheet pan, and drizzle the dough with lots of olive oil. Dimple the dough all over, and add salt and spices. Then bake at 400 degrees Fahrenheit for 20-25 minutes.

How Do I Know When Bulk Fermentation Has Ended?

Knowing when your sourdough has completed the bulk ferment stage is something you will be able to judge more accurately with time. The more sourdough loaves you bake, the more you’ll know about your dough. Here are a few ways to tell:

  • Use a clear or straight-sided container so you can clearly see that the dough has doubled. Mark the starting point with a pen, and you’ll know when the dough has doubled.
  • Rip off a small piece of dough before you place it into its fermentation container, then place the small piece of dough into a small glass, as it will be easier to tell when the dough has doubled. When the dough has doubled in the glass, it should have also finished fermentation.

Can You Skip Bulk Fermentation?

No. Bulk fermentation is an essential step especially when it comes to baking naturally leavened sourdough bread. This is where your starter becomes alive, while the yeasts and bacteria rise in your bread.

If you skip bulk fermentation, the bread won’t be airy nor rise, instead, it will be flat, gummy, and dense. Therefore, bulk fermentation must be completed.

Bulk Fermentation Sourdough

If you’re desperate for a sourdough loaf that is both crisp, and airy, with a perfectly fluffy interior, then you must ensure that your bulk fermentation is on point. A little over or under can drastically affect the results of your baked sourdough bread.

Bulk Fermentation Sourdough – FAQs

How Long Can I Bulk Ferment Sourdough?

You can bulk ferment your sourdough for 3 to 7 hours, depending on the temperature of the dough. At 78 degrees Fahrenheit, bulk fermentation usually lasts for 4-4.5 hours.

How do You Know When Sourdough Bulk Fermentation is Complete?

Once your sourdough has completed 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 Bulk Ferment Sourdough Too Long?

No. It’s best to keep an eye on your dough during the last hour of bulk fermenting. If you were to bulk ferment your sourdough for too long, you may risk over-proofing your dough.

How Much Should Sourdough Rise Bulk Fermentation?

Your dough should rise till it has doubled in size, compared to what it was before bulk fermenting. Some bakers prefer to have their sourdough rise by 30-50%, although it must double to ensure you get lots of bubbles, which will help the dough rise and expand when baking.

By Natasha Krajnc

Hi! My name is Natasha and I'm specialized in home sourdough bread baking and currently based in Slovakia - a very small country in Central Europe. My bread baking story began in 2011 when I decided to give up commercial yeast. I felt tired all the time (especially after eating bread and other foods made with yeast), I wasn’t motivated to do anything, had trouble concentrating throughout the day, my abdomen was bloated and I was like a trumpet on steroids – basically, I was quite a wreck. I was a big bread lover (and still am) and having to stop eating bread was quite hard at that time but I felt I was on a right way to give my body a chance to heal itself.

Leave a comment

Your email address will not be published. Required fields are marked *