Bulk fermentation is the cause of most sourdough bakers’ frustrations. I get a few hundred messages daily on social media, and almost all of the issues these bakers face involve bulk fermentation in some way.
My biggest issue when I started making sourdough was chronically underfermenting my dough. Believe me, it’s not just you.
Here are 12 tips to help you better understand bulk fermentation so you can nail your next sourdough loaf!
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Why is bulk fermentation so hard?
Before we get into the tips, I wanted to quickly explain why bulk fermentation is so frustrating and mysterious.
The reason? There are so many variables.
I love recipes that are specific, and sourdough bread is anything but! In fact, some people prefer to call it a sourdough formula versus a sourdough recipe for this very reason.
There is no “time” allotment for bulk fermentation. It may take me 5 hours, and it may take you 3 hours or even 15 hours.
The temperature of your home, the maturity of your starter, the type of flours you use, the temperature of your water, the humidity in your home… all of these are variables that impact the length of your bulk fermentation.
That’s why it’s such a pain in the rear end, but with the tips in this article, I hope to demystify it a bit and give you some more tools to add to your bulk fermentation tool belt.
1. Your dough temperature impacts how long the bulk fermentation will take.
This tip is first because it’s the most important one on this list.
The dough’s temperature will impact how long your bulk fermentation takes, and it’s not just a minor thing.
We’re talking hours and hours of difference! Dough that’s 67°F can take around 15 hours to finish bulk fermentation whereas 78°F dough can take under 5 hours.
Sourdough bakers rarely “watch the clock” – true masters will watch the dough.
However, having a general guideline for how long things take at different temperatures is a massive help when planning. It also gives you some context for when to start analyzing the dough and looking for other signs that the bulk fermentation is done.
Note: The Sourdough Journey’s dough temping chart shows about how long bulk fermentation takes at different dough temperatures. We’ll dive into this chart more in Tip 3.
If you can keep all of the other variables fairly consistent, you may even nail down a timeframe that you can rely on each and every time.
2. Try to control your dough temperature for a more predictable bulk fermentation timeline.
To expand on the importance of dough temperature, I suggest controlling your dough’s temperature for more consistent results.
My sourdough journey changed when I started doing this.
I now make an effort to keep my dough’s temperature around 78°F-80°F. Because I have made bread at this temperature so many times, I can predictably know how long the bulk fermentation takes, which is 4.5-5.5 hours. I like how fast it is!
You can control your dough’s temperature in a few different ways:
- Through the temperature of the water you add to the dough (this calculator helps you decide what water temperature you want)
- By taking the temperature of your dough after each stretch and fold and adjusting its environment to either raise or lower the temperature
- I put my bowl in the oven with a cup of boiling water in the corner to raise the temperature of my dough (the microwave also works if the oven is in use)
- Many people enjoy warming mats or seedling mats
- Proofing boxes are the best option of all, but they are the most expensive
3. Check out the Sourdough Journey’s percentage rise chart.
The Sourdough Journey has created an invaluable resource for sourdough bakers – a dough temping guide.
If you use a bowl with milliliter markings on the size, you can figure out when to stop the bulk fermentation based on how much the dough rises.
Dough that’s 80°F should rise around 30% in volume before shaping, whereas dough that’s 70°F should rise around 75% before shaping.
A quick example: if your dough is 80°F and 1,000ml, you should shape it when it reaches 1,300ml in your bowl.
The reason it’s different at different temperatures? The fridge!
When you put your dough in the fridge for the cold proof, warmer dough will continue fermenting at a faster pace until it cools down to the fridge temperature. So you want to cut off its bulk fermentation sooner than cooler dough to avoid overproofing.
I appreciate the dough temping and percentage rise method but don’t always use it simply because I can be a lazy baker. I have a hard time flattening out the surface of my dough to determine how many milliliters it is at the start. Yes, I’m lame for this.
Enter: the aliquot method.
4. Check out Crusty Cravings by Hannah’s Aliquot method charts.
The aliquot method is simple: take a small portion of your dough and put it in a smaller vessel. Watching how much the dough rises is a lot easier to see this way versus a big mass of dough.
Note: Aliquot means a portion of a larger whole.
Audrey, or @artisansourdoughbaker on TikTok, popularized the method of using small cups to help.
Crusty Cravings by Hannah created some charts using these jello shot cups (is that really what they’re called?). Perhaps I should more aptly call them 2-ounce condiment cups.
Anyway, depending on your dough’s temperature, you put a different amount of dough into the cup. When the dough touches the lid and tries to escape, it’s ready to shape!
For example, if your dough is 75°F, put 37g of dough into the cup. We’re looking for a 50% rise at that temperature, and 37g is exactly half of what will fit in the cup. Viola!
5. The amount of starter in your dough will impact how long the bulk fermentation takes.
Dough with lots of starter in it will ferment faster than dough with less starter in it.
I like to use this to my advantage when planning!
For example, if I want my bread dough to ferment overnight without overproofing, I’ll use just 5% starter in my recipe.
If I want things to go quickly, I’ve gone as high as 50% starter in my recipe.
Note: Baker’s percentages always relate to the flour. So, if I use 5% starter in a recipe with 500g flour, it means I used 25g of starter.
6. The dough will have lots of bubbles around the sides, on the bottom, and starting to appear on the surface.
One of the reasons I like mixing my dough in a glass bowl is so I can see the bubbles. These glass bowls are my favorite and can fit up to 3 loaves at a time.
A well fermented dough will have lots of bubbles appearing around the side and bottom of the bowl. If you look at the surface, bubbles will start to appear there as well.
7. The stickiness of your dough is a great bulk fermentation indicator.
As your dough progresses through the bulk fermentation, its characteristics shift.
Upon mixing, the dough is very shaggy and sticky.
As you do each round of stretch and folds or coil folds, the dough starts to smooth out, becoming less sticky each time.
When the bulk fermentation is done, I find my dough (usually at 68-72% hydration) is no longer sticky on the surface. It’s either smooth or just slightly tacky.
Using a dry finger, I can touch the surface of my dough and it will not stick or hang on to my finger.
This is one indicator I look for when assessing my dough.
Please note that if you are using a high-hydration recipe (i.e.: lots of water in the dough), your dough will probably be sticky no matter what, even when the bulk fermentation is finished.
My bread recipe is typically around 68-72% hydration, so that’s what this tip is based on.
8. The dough is domed on the edges where it meets the bowl.
When the dough is nearing the end of bulk fermentation, it will be domed on the edges where it touches the bowl.
Looking for this curve in the dough can help gauge the end of bulk fermentation, but use it with other indicators mentioned in this article.
9. If the dough is willing to pull away from the bowl, that’s generally a good sign.
If you use a finger to gently pull at the edge of the dough, where it touches the bowl, is it willing to release without sticking and hanging on for dear life?
In my experience, this has been a good indicator that the bulk fermentation is done.
When I use a glass bowl, I even find that I can tilt the bowl, and the dough will start sliding out.
This is less common with stainless steel bowls or plastic containers, so don’t panic if you have to use a bowl scraper or your finger to get it out.
Cooler dough also tends to hang onto the bowl more than warmer dough, so like many of these tips, use it in conjunction with other signs.
10. Tap the side of the bowl and see if your dough jiggles.
We want a very jiggly dough! Tap the edge of the bowl or gently shake it from side to side. If it doesn’t move much, it’s likely not done fermenting and rising.
If it’s super jiggly, it means it’s full of carbon dioxide, which is what gives us that nice rise and cloudlike texture.
Without that, you end up with dense bread and a very closed crumb.
11. Try the poke test.
In Karyn Newman’s book, Sourdough by Science, she talks about the poke test, and I’d like to include an excerpt here that really helped me:
“Eventually your dough will have risen and you’ll want to know if it’s ready. ‘Ready’ means it has enough gas and it has a strong gluten network to hold the gas in the dough through baking.
There is also a stage way past ready called over-fermented in which the yeast has eaten all the food in the dough and will no longer be able to make new gas, and the bacteria in the dough have decided to eat the gluten network. You can see this would be bad––no gas, no gluten network, no puffy bread.
The poke test can help you figure out if your dough is ready and if it is in danger of becoming over-fermented anytime soon. I find this test is also useful in assessing whether a loaf is ready to bake.
A caveat: The poke test is not as useful in whole grain doughs and should never be used on refrigerated dough, which is too cold and stiff to spring back.”
Here’s how you do the poke test:
- Poke a wet finger half an inch into the dough for a second, then remove. I also have found a floured finger to work well.
- If it springs back quickly: it’s not ready yet.
- If the hole stays there and doesn’t spring back at all: it’s overfermented.
- If the hole starts to spring back slowly, perhaps not completely, it’s likely ready.
12. After the pre-shaping, your dough should have bubbles on the surface.
Sourdough Bulk Fermentation FAQs
When does bulk fermentation start?
Bulk fermentation starts as soon as the sourdough starter is introduced to the dough.
Does bulk fermentation include stretch and folds?
Yes, bulk fermentation is happening during stretch and folds. It begins as soon as the starter is added to the dough.
How long is bulk fermentation?
Bulk fermentation times will differ depending mainly on the temperature of your dough and how much starter is in your recipe. Refer to the tips in this article to get a better understanding of bulk fermentation timelines.
Why is my sourdough sticky after bulk fermentation?
Your sourdough may be sticky if you let the bulk fermentation go too long. Overproofed dough will be very sticky, loose, and impossible to shape. Keep in mind that high-hydration dough, such as ciabatta dough, will be sticky even when properly bulk fermented.
What do you do after bulk fermentation?
When the bulk fermentation is finished, you will pre-shape, shape, and cold proof your dough. If you’re opting for same-day sourdough bread, you can skip the cold proof and instead do the second rise on the counter.
What should sourdough look like after bulk fermentation?
Well-fermented dough has tons of bubbles, is very jiggly, and is domed on the edge where it meets the bowl. When you touch it, it’s smooth or tacky, not overly sticky. When you tilt the bowl or pull on the edge of the dough, it’s willing to slide out of its container or at least release from the side of the bowl.
How do I speed up bulk fermentation?
You can speed up bulk fermentation by keeping your dough warm (78°F-82°F) and/or using a higher percentage of starter in your dough.
What is the best temperature for sourdough bulk fermentation?
You can bulk ferment your sourdough at virtually any temperature between 50°F-85°F. Yeast is most active between 76°F-82°F, so many say this is the best temperature for bulk fermentation. However, others prefer the longer fermentation at cooler temperatures, which can lead to a more sour-tasting bread. I personally like 78°F.
Related: A Love Letter to Discouraged Sourdough Bakers
Conclusion
Bulk fermentation is the hardest part of sourdough baking because there’s no “easy” answer for everyone. It will differ from baker to baker and environment to environment.
But failing, experimenting, and learning to read the dough will eventually lead you to a firm understanding of bulk fermentation.
Under or over-proofed dough is not a loss; it can be salvaged into croutons, French toast, or focaccia (just to name a few ideas). More importantly, it teaches you what tweaks to make to your timing for next time.
Refer to this crumb reading guide from The Sourdough Journey to learn how to read a crumb.
Sourdough is definitely a journey, but it’s so worth it.
You are the bomb! You have really helped me take my sourdough bread to a new level. I recently came across one of your videos by happenstance (how to make fluffy sourdough bread), and that video was the jumping off point to The Sourdough Journey, which helped me understand the science and whys of sourdough fermentation. I used your basic recipe, temperature and time table, and I have gotten really good consistent results… and getting better with experience. Thank you!
Aw I’m so happy to hear that!
thank you. I’m learning that sourdough is a “journey”.
Thank you so much for sharing this wonderful post with us.