Reading bulk fermentation

Bulk fermentation is the first rise, from mixing until shaping. It is where the dough gains most of its flavour and strength, and it is the step that most often goes wrong. The clock is a poor guide; temperature and the dough itself are better ones.

Temperature sets the pace

These are rough times for a dough with 20% levain. Treat them as a starting point.

Dough temperature	Approximate bulk time
28 °C (82 °F)	3–4 hours
26 °C (79 °F)	4–5 hours
24 °C (75 °F)	5–6 hours
21 °C (70 °F)	7–9 hours
18 °C (64 °F)	10–12 hours

A probe thermometer pushed into the dough tells you where you are. To steer the temperature, change the water you mix with: warmer water in a cold kitchen, cooler water in a hot one. An oven with only its light switched on makes a serviceable warm spot.

Folding

Folds build strength in place of kneading.

• Stretch and fold: with a wet hand, lift one side of the dough, stretch it up and fold it over the middle. Turn the bowl a quarter and repeat four times.
• Coil fold: lift the dough from the middle with both hands and let the ends tuck underneath. Gentler, and better for wet doughs.

Three or four sets in the first two hours is typical. Stop when the dough holds its shape for a few minutes after a fold.

Signs that bulk is finished

Use a straight-sided container and mark the starting level, so you can read the rise.

• Volume up by roughly 50–75%
• A domed surface where the dough meets the container
• Bubbles visible on top and through the sides
• The whole mass jiggles when you shake the container
• The dough feels airy and pulls away from the sides cleanly when tipped

Too early, too late

	Looks and feels like	In the finished loaf
Underfermented	Dense, heavy, few bubbles	Tight crumb with a few large tunnels; gummy
Overfermented	Slack, very sticky, collapsing, sharply sour	Flat loaf that spreads; pale crust

If you are unsure, slightly under is easier to rescue: the final proof gives the dough more time.