Levain
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Reading bulk fermentation

The clock is a starting point, not the answer. Temperature, starter strength, hydration, and flour all shift the timeline. Here's how to read the dough itself.

The 4°C rule

Every 4°C drop in ambient temperature roughly halves fermentation speed. At 26°C, bulk might finish in 4 hours. At 22°C, expect 6–7. At 18°C, 10–12. This is why "5 hours" from a recipe never transfers directly — it was written in someone else's kitchen.

Phase by phase

First hour

What you see

Dough feels dense and tight. No visible activity.

What to do

Nothing to do. Yeast needs time to wake up. Resist the urge to add flour.

Hours 2–3

What you see

Dough starts to feel lighter, slightly puffy. Small bubbles at the edges of the bowl.

What to do

Perform stretch-and-folds. Four sets over the first two hours improves structure dramatically.

Midpoint

What you see

Dough is noticeably more aerated. Wobbles like jello when you shake the bowl. Dome forms on top.

What to do

Stop folding. Let it run.

Ready to shape

What you see

Volume increased 50–75%. Bubbles on sides and top. Dough domes and doesn't spring back quickly when poked. Smells pleasantly sour, not alcoholic.

What to do

Shape immediately. Don't wait for a second sign — it rarely comes.

Overproofed

What you see

Volume more than doubled. Dough is slack, sticky, won't hold shape. Smells strongly alcoholic or acetone-like.

What to do

Bake immediately in a tin. It won't recover. Note your room temperature and start time for next time.

Note your bulk time

Log the hours and ambient temperature after each bake. Three or four entries and you'll know exactly what bulk looks like in your kitchen in every season.

Start your bake log