How to Bulk Ferment Sourdough Like You Actually Know What You're Doing

Bulk fermentation is where most home bakers quietly lose the plot. Not because they don't care, but because every recipe gives you a time range like '4 to 8 hours' and then leaves you completely on your own. Four to eight hours. Cool, thanks. Very helpful.

Here's the thing: bulk fermentation isn't really about time at all. It's about what's happening inside your dough. Once you start reading the dough rather than the clock, everything starts to click. This one shift has probably done more for my bakes than any flour upgrade or fancy banneton ever has.

What Bulk Fermentation Is Actually Doing

During bulk, your starter is eating the sugars in the flour and producing CO2 and organic acids. The CO2 inflates the gluten network, giving your dough volume. The acids develop flavour and also strengthen the dough structure over time. Both things need to happen, and they need to happen together, which is why temperature and timing are so tightly linked.

Too short and the dough hasn't developed enough gas or flavour. Too long and the acid starts to break down the gluten, leaving you with a sticky, slack mess that won't hold shape. Neither of those bakes well.

The Signs Your Dough Is Ready

Forget the clock. Look for these instead:

• Volume increase: You're looking for roughly 50 to 75 percent growth, not a full double. A straight-sided container makes this genuinely easy to track. Put a rubber band or a bit of tape at the starting level and check back.
• Domed top: The surface should be domed and slightly jiggly, with some bubbles visible around the edges and top. If it's starting to collapse in the middle, you've gone too far.
• The poke test: Wet your finger and poke the dough gently. It should spring back slowly but not all the way. A dough that snaps back immediately needs more time. One that doesn't spring back at all has over-fermented.
• Texture change: By the end of bulk, your dough should feel lighter and more aerated than when you started. It'll have a slightly webby, open texture if you pull a bit away.

How Temperature Changes the Game

This is where it gets interesting, especially in spring when kitchen temps are all over the place. A dough fermenting at 24°C might be ready in four and a half hours. The same dough at 19°C could take seven or eight. Neither is wrong. They're just different, and both can produce a brilliant loaf.

Cooler kitchens mean slower, longer ferments, which often develop more flavour. Warmer kitchens speed things up, so you need to watch more closely. As the weather warms up through spring, keep an eye on this because your timing from a cold February bake won't carry over.

What to Do During Bulk (Not Just Watch)

Bulk fermentation isn't passive waiting. In the first two hours, you should be doing stretch and folds every 30 minutes or so, around three or four sets. These strengthen the gluten network and help the dough trap gas more effectively later on. After that, leave it alone and let the fermentation do its thing.

When You're Still Not Sure

Honestly, even experienced bakers have bakes where they're genuinely unsure whether the bulk is done. That uncertainty doesn't go away entirely, but it does get smaller the more you bake. If you want a shortcut through that learning curve, the DoughRise Coach is worth looking at. It gives you personalised bake plans, unlimited AI coach messages, and real technique guidance you can use mid-bake when you're staring at your dough wondering what on earth is going on. It's like having a knowledgeable mate on call, which is exactly what bulk fermentation calls for sometimes.

Once you get comfortable reading bulk fermentation properly, a whole lot of sourdough problems solve themselves. Bad crumb structure, poor oven spring, dense loaves , a lot of that traces back here. Get this stage right and the rest of the bake has a much better chance of going well. There's more on technique, troubleshooting and starter care over at doughrise.store whenever you're ready to dig further in.

Happy baking! Find everything you need at doughrise.store

Photo by Balint Mendlik on Unsplash