A Guide to Bulk Fermentation
When it comes to baking sourdough, bulk fermentation is one of the most crucial stages in developing flavor, texture, and structure in your bread. If you’re new to sourdough or looking to refine your technique, understanding this process can elevate your baking skills. Let’s dive into what bulk fermentation is, why it matters, and how to master it.
What is Bulk Fermentation?
Bulk fermentation is the period after mixing your ingredients—sourdough starter, flour, water, and salt—when the dough is allowed to rise as a single mass. This phase typically lasts several hours and is essential for developing the dough’s gluten structure, enhancing its flavor, and allowing the natural yeast and bacteria to do their magic.
Why is Bulk Fermentation Important?
Flavor Development
During bulk fermentation, the yeast ferments the sugars in the dough, producing carbon dioxide and organic acids. These acids not only contribute to the tangy flavor characteristic of sourdough but also enhance the overall taste profile. The longer the fermentation, the deeper the flavor becomes.
Gluten Development
As the dough ferments, gluten strands continue to form and strengthen. This elasticity is vital for holding the gas produced during fermentation, leading to a well-risen loaf with a light, airy crumb.
Structure & Texture
Bulk fermentation allows the dough to relax and expand, creating a strong structure that helps the bread rise properly during the final proofing and baking stages. A well-fermented dough will have a pleasant texture, with an open crumb and a crispy crust.
How to Master Bulk Fermentation!
Bulk fermentation can vary based on factors like room and dough temperature, the strength of your starter, and the specific recipe you are following. Most recipes will tell you to wait for your dough to double or to wait a specific amount of time, while this advice can work, it’s not always the best advice to follow. To master this, we need to look at our dough temperature and the percent rise we want our dough to achieve, not the clock! You will need a probe thermometer to get the most accurate reading of your dough temperature. To take your dough temperature place the probe tip into the center of your dough. Below is a table that lays out the target rise we want based on the temperature of our dough!
Dough Temperature Target Rise Percentage Approximate Timing
80°F/27°C 30% 5.5 Hours
75°F/24°C 50% 7 Hours
70°F/21°C 75% 12 Hours
65°F/18°C 100% 16 Hours
Most of us will not be using a straight sided vessel for our dough. To accurately calculate the percentage rise we will need to place a few markers on the outside of our bowl. You can mark directly on the bowl or use painters tape.
Measuring Steps:
Place your empty bowl on your scale. When measuring water, milliliters = grams. Pour water in increments of 100 and place hashmarks with labels on the outside of your bowl. Keep labeling until you reach the top of your bowl.
The first marker will be the beginning volume - this is the leveled volume of dough after all the ingredients are combined. Measure this after the autolyse step.
Once you have completed the stretch and fold process take the temperature of your dough from the center and refer to the corresponding percentage found on the table above.
The next marker we will place is the target rise volume - once you have your dough temperature and corresponding percentage, multiply your beginning volume by 1 + percentage rise. This will be your total target volume.
Now just sit back and wait for your dough to hit that target rise mark!
Math Example:
*Using a loaf with 75% hydration*
500g flour will typically mix up to be 750mL
750mL - beginning volume
Dough temperature = 70°F = 75% target rise
750mL x 1.75 = 1,313mL (round to 1,300mL) - target rise volume
Tips & Notes:
You want to try to keep your dough temperature consistent.
Monitor your dough temperature (every 30-60 minutes) throughout the bulk fermentation and adjust the target rise volume accordingly.
If you are working with inclusions and you add them in during the stretch and fold process, wait until the inclusions are added to mark your beginning volume.
Calibrate your process - once you bake your loaf read the crumb. If it looks over proofed decrease the percent rise by 5-10%; if it looks under proofed increase the percent rise by 5-10%.
Keep a baker’s notebook to track your bakes and as a reference guide. Once you get the hang of it you’ll be able to read your dough without trying!
How to Read your Dough
As you continue on your sourdough journey you will be able to read your dough. At the end of bulk fermentation, a well-developed dough should exhibit several key qualities:
Increased Volume: The dough should have noticeably risen. This indicates that fermentation has occurred and gas has been produced.
Jiggly & Bubbly: You should see small bubbles forming on the surface and throughout the dough, a sign of active fermentation and gas retention.
Smooth Texture: The dough should feel smooth and elastic when you handle it. It should no longer be sticky, although it may still feel slightly tacky.
Pillowy & Soft: The dough should feel light and airy, demonstrating that it has trapped gas effectively.
Dough Structure: If you gently stretch the dough, it should have good extensibility and hold together without tearing easily. This indicates proper gluten development.
Aromatic: The dough should have a pleasant, slightly tangy aroma from the fermentation process, indicating that the yeast and bacteria are working effectively.
Temperature: The dough may feel slightly warm to the touch, reflecting the heat generated during fermentation.
These qualities indicate that the dough is well-fermented and ready for shaping or the next step in your baking process.
Conclusion
Mastering bulk fermentation is key to producing delicious, artisan-quality sourdough bread at home. By understanding the importance of this phase and learning to observe your dough, you’ll be well on your way to achieving loaves with incredible flavor and texture. So next time you bake, take a moment to appreciate the magic happening during bulk fermentation—your taste buds will thank you! Happy baking!
