Fermentation – time, temperature and how to tell the dough is ready
A table of proofing time against temperature and yeast quantity, plus a visual guide to what a ready, underproofed and overproofed dough ball looks like.
Quick answer: fermentation time depends on temperature and the amount of yeast – the warmer it is, the faster it goes. A dough at 25 °C ferments roughly twice as fast as the same dough at 18 °C, and much faster than in the fridge. Look at the dough, not just the clock: it should have grown noticeably, feel light and airy, and spring back slowly when you press it with a finger.
The effect of temperature – why it is so big
Yeast activity is strongly temperature-dependent, and the relationship is not a straight line. Between about 18 and 30 °C, activity roughly doubles for every 7–8 degrees warmer. Below 15 °C the yeast slows down even more sharply per degree – which is why the fridge’s 4 °C makes such a big difference compared with room temperature (see cold fermentation).
| Temperature | Relative speed vs 25 °C |
|---|---|
| 4 °C (fridge) | approx. 1/15 |
| 12 °C | approx. 1/5 |
| 18 °C (cool room) | approx. 1/2 |
| 22 °C (normal room temperature) | approx. 3/4 |
| 25 °C | 1 (reference) |
| 30 °C | approx. 1.5 |
The figures are rounded guide values from an established yeast growth model – not an AVPN rule and not results of our own – so treat them as a pointer, not a to-the-minute answer key.
How to tell the dough is ready
- Ready: clearly bigger (not necessarily exactly double), feels light and full of air, the surface is smooth and slightly glossy, and a finger dent fills back in slowly.
- Underproofed: feels heavy and dense, the finger dent springs straight back, and the dough doesn’t give at all.
- Overproofed: flat, shiny and full of large, uneven bubbles under the surface; the finger dent sinks in without springing back at all. See overproofed dough for how much can be rescued.
Room temperature or cold fermentation?
Room-temperature fermentation is faster and needs less planning, but leaves less time for flavour to develop. Cold fermentation in the fridge takes longer but needs less yeast and, according to most bakers, gives a rounder flavour – our house method runs 48 hours. See cold fermentation for how to set it up and yeast for how much of each yeast type you actually need. Work out the exact time and quantity in the calculator.
If the dough doesn’t seem to be rising at all, see dough not rising.
