A typical pizza recipe gives one yeast amount and one rising time, and says nothing about the kitchen it was tested in. This guide turns it around: you choose when you want to bake, and the pizza calculator's model gives the amount of instant yeast for that time at your kitchen temperature. Every number is the model's prediction, with its range; the dough has the last word.
Instant yeast by rising time and kitchen temperature
The amounts are a percentage of the flour weight, for a dough that stays at room temperature the whole time and is ready to bake at the end: the balls have roughly doubled, look airy, and a floured fingertip leaves a dent that fills back in slowly. The range in parentheses is the model's.
| Ready in | 18 °C (64 °F) | 22 °C (72 °F) | 26 °C (79 °F) |
|---|---|---|---|
| 4 hours | outside the model | 0.27% (0.18%–0.4%) | 0.15% (0.1%–0.22%) |
| 6 hours | 0.3% (0.2%–0.44%) | 0.15% (0.099%–0.22%) | 0.081% (0.054%–0.12%) |
| 8 hours | 0.2% (0.13%–0.29%) | 0.095% (0.064%–0.14%) | 0.052% (0.035%–0.078%) |
| 12 hours | 0.11% (0.072%–0.16%) | 0.052% (0.035%–0.077%) | 0.029% (0.019%–0.042%) |
"Outside the model" means the dough would need more yeast than the model is calibrated for, so it gives no amount. In an 18 °C (64 °F) kitchen, 4 hours is too short for this model: give the dough more time, or mix it with warmer water and keep it somewhere warmer.
Mix the dough and let it rise in one piece for the first two-thirds of the time, then divide it and shape the balls; they rise for the last third. That is how the pizza dough calculator lays out its schedule.
The same in grams, for 500 g of flour
| Ready in | 18 °C (64 °F) | 22 °C (72 °F) | 26 °C (79 °F) |
|---|---|---|---|
| 4 hours | outside the model | 1.3 g | 0.74 g |
| 6 hours | 1.5 g | 0.73 g | 0.40 g |
| 8 hours | 0.98 g | 0.47 g | 0.26 g |
| 12 hours | 0.53 g | 0.26 g | 0.14 g |
An 8-hour dough at 22 °C (72 °F) needs about 0.47 g of instant yeast for 500 g of flour (0.095%); a 4-hour dough about 1.3 g, and a 12-hour dough about 0.26 g. Four 250 g balls at about 65% water take roughly 600 g of flour, so multiply the grams by 1.2.
Weighing less than 1 gram
Ordinary kitchen scales read in whole grams, so they cannot weigh 0.26 g or 0.47 g. Two ways around it, both common practice:
- A 0.01 g scale. Small pocket (jewelry) scales read to a hundredth of a gram and are inexpensive. A scale that reads to 0.1 g is fine from about 1 g; below that, use a 0.01 g scale or the solution.
- A yeast solution. Stir a whole 7 g packet of instant yeast into 500 g of room-temperature water, separate from the recipe's water. Every 10 g of that mixture then holds about 0.14 g of yeast. To find how much mixture you need, multiply the grams of yeast by 72: for 0.47 g, that is about 34 g of mixture. Use it within 30 minutes and throw away the rest. When you mix the dough, use as many grams less water as the grams of mixture you add.
The pizza calculator uses the same trick for small amounts, though it may dissolve the packet in less water; when you use it, follow its numbers for the water and the mixture.
Fresh yeast or active dry
The amounts above are for instant (rapid-rise or quick-rise) yeast. The model converts with the usual conversion factors: use about 3 times as much fresh yeast, or about 1.2 times as much active dry yeast.
Why twice the yeast is not half the time
Doubling the yeast does not halve the rising time. Yeast multiplies during a long rise, so a small starting amount partly catches up; the model's slope comes from the practice tables it was fitted to. The guide to pizza dough temperature shows the same effect from the other side, as hours for a fixed amount.
Room temperature only
These amounts are for a dough that stays at room temperature from mixing to baking, and they assume the room holds its temperature. A kitchen that warms up in the afternoon or cools at night moves the dough faster or slower than the table. For dough that spends a day or more in the fridge, the amounts are far smaller and follow a different part of the model: see cold ferment pizza dough. And if a dough has already been out all night, can pizza dough sit out overnight covers what the yeast amount does by morning.
Check the dough, then bake
Whatever the table says, the dough decides. Ready balls have roughly doubled, look airy, and the dent from a floured fingertip fills back in slowly. If they spring back at once, give them more time; if they are slack and covered in large bubbles, bake them soon. If nothing seems to happen at all, see why pizza dough is not rising.
For your own numbers, put your room temperature, the time you want to eat and the number of pizzas into the pizza dough calculator. It gives the yeast with its range, the grams and a schedule back from dinner.