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Fermentation Time Calculator

Enter how long your recipe says the dough takes to rise and at what temperature, and see how long it will take at yours.

°F

Measure the dough with a probe thermometer, or use the room or fridge temperature.

Your recipe says
h
°F

Hours as a decimal: 1.5 is 1 h 30 min. Most recipes assume 75–78 °F (24–26 °C).

Your estimated rise time

Your dough is 7 °F cooler than the recipe's 75 °F, so expect the rise to take about 2 h 35 min instead of 2 h.

Rise time
2h 35mestimate
Speed
1.31×longer
Dough
68 °Fyours
Rise time at other temperatures
DoughEstimated time
38 °F8 h 20 min
50 °F5 h 15 min
60 °F3 h 35 min
65 °F2 h 55 min
68 °Fyour dough2 h 35 min
70 °F2 h 25 min
75 °Frecipe2 h
80 °F1 h 40 min
85 °F1 h 20 min
90 °F1 h 5 min

This is an estimate from a rule of thumb, not a timer. Yeast amount, salt, sugar and flour change the speed too, so plan with the time and judge the dough: about doubled, and it springs back slowly when poked.

How it works

Yeast works faster in a warm dough and slower in a cool one. A common rule from pizzeria practice, given in John Correll's Encyclopizza, is that yeast activity doubles for every 18 °F (10 °C) the dough warms up, up to 100 °F. So the rise time halves for every 18 °F warmer and doubles for every 18 °F cooler:

time = recipe time × 2 ^ ((recipe temp − your temp) ÷ 18) in °F

time = recipe time × 2 ^ ((recipe temp − your temp) ÷ 10) in °C

Worked example

  1. The recipe says the dough doubles in 2 hours at 75 °F. Your kitchen, and the dough, is at 68 °F.
  2. 75 − 68 = 7 °F cooler, and 7 ÷ 18 = 0.39.
  3. 2 ^ 0.39 = 1.31, so the rise takes 1.31 times as long.
  4. 2 h × 1.31 = 2.6 h, about 2 h 35 min.

Encyclopizza's own examples: 88 °F dough ferments twice as fast as 70 °F dough, and 70 °F dough twice as fast as 52 °F dough. The rule covers 33 °F, where the rise is slowest, up to 100 °F; above that yeast slows down again, so the calculator stops there.

FAQ

How does temperature change fermentation time?

Warmer dough rises faster and cooler dough slower. John Correll’s Encyclopizza puts it as a rule: yeast activity doubles for every 18 °F (10 °C) the dough warms up, up to 100 °F. So a dough that doubles in 2 hours at 75 °F needs about 4 hours at 57 °F.

Should I use the room temperature or the dough temperature?

The dough temperature, if you can measure it with a probe thermometer. Dough mixed with warm or cold water can be several degrees off the room for hours. If you only know the room temperature, use it; the estimate is close once the dough has settled to the room.

How long does dough take to rise in the fridge?

At a steady 38 °F, about four times as long as at 75 °F by the rule above. In practice a dough is often ready sooner, because it takes hours to cool all the way through and keeps rising faster while it does. Encyclopizza notes that dough keeps rising at any temperature above 32 °F, so even cold dough will over-rise eventually.

Why is this only an estimate?

Yeast amount, salt, sugar, flour and the starter’s strength all change the speed too, and the doubling rule is a rule of thumb, not a lab model. Use the time to plan your day, then judge the dough itself: it should look about doubled and spring back slowly when poked.

Does it work for sourdough?

Use it the same way: enter how long your bulk ferment usually takes at a known temperature, then see how the time moves when the kitchen is cooler or warmer. A sourdough rises more slowly than a yeasted dough, but both speed up with warmth.

Sources