Fermentation: Time and Temperature

Bulk fermentation at 24-26 degrees Celsius takes about 3-4 hours for a yeasted dough; colder dough ferments more slowly.

Bulk fermentation is the first rise after mixing. At 24-26 degrees Celsius a standard yeasted dough completes bulk in roughly 3-4 hours. At 20 degrees the same dough needs noticeably longer; at 28 degrees it can finish ahead of the schedule you planned. The dough temperature, not the room temperature, is the number that matters.

Baker's yeast is Saccharomyces cerevisiae, the same species used for beer and wine. Its activity scales with temperature: warmer dough ferments faster, colder dough slower. Holding bulk at a known temperature is what makes the 3-4 hour window repeatable.

The Chorleywood Bread Process, developed in 1961 at the British Baking Industries Research Association in Chorleywood, took the opposite approach: high-speed mixing cut fermentation to minutes. It is the industrial counterpoint to a long, cool bulk, and both rely on the same yeast species.

Raymond Calvel developed the autolyse technique — a rest of flour and water before salt and yeast are added — and promoted the baguette's open crumb in the twentieth century. The rest lets flour hydrate and gluten begin to develop without mechanical work, shortening total mixing time.

A finished loaf reads about 90-99 degrees Celsius in the centre on a kitchen thermometer. Schedule backwards from that reading: bulk, shape, proof, then bake until the centre reaches the target.

• 20°C: bulk runs longer than 4 hours — check by dough feel, not clock.
• 24-26°C: the standard window, about 3-4 hours.
• 28°C: bulk accelerates; watch for over-proofing before the hour is up.
• Finished loaf: centre reads 90-99°C.

Further reading

• Flour and Protein
• Hydration and Baker's Percentages