How to Tell When Bulk Fermentation Is Done

Dough Dough Guides

If one stage makes or breaks a loaf, it's the bulk ferment — and it's the one beginners get wrong most often, almost always by going off the clock instead of the dough. Here's exactly what I look for, and the simple trick that takes the guesswork out for good.

By Richard — I bake fresh sourdough every day in a kitchen that sits around 22–23°C, and I never judge a bulk rise by time alone. Watch the dough, not the clock.

What bulk fermentation is — and why it matters so much

The bulk ferment (or "bulk rise") is the long first rise after you've mixed your dough and before you shape it. It's where the dough gains its strength and structure, fills with gas, and develops most of its flavour. Get it right and everything afterwards is easy; get it wrong and no amount of good shaping or a hot oven will save the loaf. Most dense, gummy or flat loaves come down to a bulk that was cut short or left too long.

The signs it's actually done (not the clock)

A recipe that says "6 hours" is only ever a rough guide — your kitchen, your starter and your flour all change the timing. These are the signs I actually go by:

The jar trick (my favourite shortcut)

This removes all the guesswork. When you start the bulk, pinch off a small sample of dough and press it into a straight-sided jar or glass. Mark the starting level with an elastic band or a marker, and let it rise alongside your main batch in the same spot. When the sample has climbed to your target — about 50% up — the whole batch is ready. You're measuring the rise directly instead of guessing. I use this constantly.

Temperature dictates everything

Bulk fermentation is really just a temperature game. Warmer dough ferments faster; cooler dough slower. That's why I mix to a target dough temperature of ~25°C (I check it with a probe thermometer and adjust my water temperature to hit it) and aim to bulk at 24–26°C. My cooler kitchen runs slower than most recipes assume, so I simply give it longer, or find a warmer spot — rather than panicking when the clock says it "should" be done.

Under-proofed vs over-proofed

You're aiming for the middle: risen, domed and airy, but still holding its shape and with some tension left to it.

The poke test (after shaping and proof)

Flour a finger and gently press into the dough about a centimetre. If it springs back slowly and only part-way, leaving a slight dent, it's ready. If it springs back instantly and completely, it needs more time. If it doesn't spring back at all and the dent stays, it's over-proofed — bake it now and shorten things next time.

Common bulk-fermentation mistakes

• Going by the clock. The number one error. Your kitchen is not the recipe's kitchen.
• A cold kitchen. Dough at 18°C can take twice as long as the recipe says — that's normal, not a failure.
• Using a sluggish starter. If it wasn't bubbly and at its peak, the bulk will crawl. Check it floats first.
• Waiting for a full double. For most loaves, that's too far. Trust the 30–50% range.

Once your dough is properly fermented, it's ready to shape. And if a loaf still comes out dense or flat, my loaf troubleshooting guide will tell you which way you missed.