A 24-hour pizza dough at room temperature needs about 0.018% instant yeast at 22 °C (72 °F) by the pizza calculator's model, about 0.09 g for 500 g of flour, and the amount depends on the kitchen more than on anything else. Each recipe gives one figure, anywhere from "a pinch" to a tenth of a gram, and rarely says what temperature it was written for. This guide gives the model's amount for a dough that stays out for 24 hours from mixing to baking, at 16–28 °C (61–82 °F), in percent and in grams, and shows how to weigh an amount that small. The numbers are predictions with a range; the dough has the last word.

Instant yeast for 24 hours at room 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 of the 24 hours: the balls have roughly doubled and look airy, and a floured fingertip leaves a dent that fills back in slowly. The model lays the day out the way the pizza dough calculator does for its room-temperature plans: the dough rises in one piece for the first two-thirds of the time, about 16 hours; then it is divided and the balls rise for the last third, about 8 hours. For dough mixed at 7 p.m., that is dividing at about 11 a.m. and baking at 7 p.m.

Kitchen Instant yeast, % of flour For 500 g flour Model range, % of flour
16 °C (61 °F) 0.057% 0.28 g 0.038%–0.084%
18 °C (64 °F) 0.038% 0.19 g 0.026%–0.056%
20 °C (68 °F) 0.026% 0.13 g 0.018%–0.039%
22 °C (72 °F) 0.018% 0.09 g 0.012%–0.027%
24 °C (75 °F) 0.013% too little to measure 0.0091%–0.02%
26 °C (79 °F) 0.01% too little to measure 0.0069%–0.015%
28 °C (82 °F) 0.0081% too little to measure 0.0055%–0.012%

At 22 °C (72 °F) the model predicts 0.018% instant yeast (range 0.012%–0.027%), which is about 0.09 g for 500 g of flour. A 7 g packet is about 76 times that amount. As fresh (cake) yeast it would be about 0.28 g, using the model's usual conversion of three times the instant-yeast weight. From 26 °C (79 °F) up the amounts fall to 0.01% and below, the smallest dose the model was checked against, so treat those rows as extrapolation.

"Too little to measure" is the calculator's own limit. Under 0.07 g of yeast for the batch, even the yeast-solution method described below gives less than 10 g of mixture to weigh, so the calculator gives no amount and says to choose a shorter plan or a cooler spot. For 500 g of flour that limit is reached at 24 °C (75 °F); a larger batch, say 1.2 kg of flour for eight pizzas, needs 2.4 times the yeast and stays measurable across the whole table (about 0.1 g at 28 °C (82 °F)). In a warm kitchen the 24-hour room-temperature dough is not a good plan: use 8–12 hours instead (how much yeast for pizza dough), put the dough in the fridge (cold ferment pizza dough), or switch to levain, whose amounts are easy to weigh (sourdough pizza dough overnight at room temperature).

A published 24-hour recipe, read through the model

Gozney's 24-hour Neapolitan pizza recipe uses 0.1 g of dry yeast for 500 g of flour, which is 0.02% of the flour (plain arithmetic). Read as instant yeast, the model predicts that dough is ready after about 22½ h in a 22 °C (72 °F) kitchen (range 17½–29½ h), about 28½ h at 20 °C (68 °F) and about 15½ h at 26 °C (79 °F); read as active dry, about 26 h at 22 °C (72 °F). So the recipe and the model agree for a kitchen at about 22 °C, and the same dough runs well past a day in a cooler room and is done by the evening in a warm one. That is the point of the table: the recipe's number is right for one kitchen, and that kitchen may not be yours.

Weighing a tenth of a gram

Ordinary kitchen scales read in whole grams, and even a 0.1 g scale is rough at these amounts. Two ways around it, both common practice:

  • A 0.01 g scale. A small pocket scale that reads to a hundredth of a gram weighs 0.09 g directly. Put a scrap of paper on the scale and tare it, then add yeast until it reads the amount you need.
  • A yeast solution. Stir 7 g of instant yeast into 1000 g of room-temperature water, separate from the recipe's water, until no granules are left (twice the water of the 4- to 12-hour guide, so these smaller amounts still weigh at least 10 g). Every gram of yeast you need is then about 144 g of that mixture, so for the 22 °C (72 °F) amount above (0.09 g for 500 g of flour) weigh out about 13 g of mixture, and use that many grams less water in the dough. Stir again right before you weigh, because the yeast settles. Use it within 30 minutes and throw the rest away. The water in the mixture comes out of the recipe's water, so the hydration does not change. The pizza dough calculator uses the same method for amounts under 3 g; with its shorter plans it often dissolves the packet in less water, so follow its numbers when you use it.

Why 24 hours takes so little yeast

Halving the yeast does not double the rising time. Yeast multiplies during a long rise, so a small starting amount partly catches up; in the model, half the yeast means about 1.6 times the time, not twice. Read the other way, a 24-hour dough needs far less than half the yeast of a 12-hour one: at 22 °C (72 °F) the model gives about 0.26 g for 12 hours and about 0.09 g for 24, for 500 g of flour. How much yeast for pizza dough has the 4- to 12-hour amounts, and pizza dough temperature shows the same model as hours for a fixed amount.

The room has to hold its temperature for a day

Twenty-four hours covers a night and a day, and few kitchens hold one temperature for that long. The model assumes they do. A kitchen that drops 4 °C (7 °F) overnight ferments the dough more slowly than the table predicts while you sleep, and afternoon sun through a window speeds it up. Two ways to handle that:

  • Use the temperature the dough will average, measured where the tub sits rather than where you stand, and check the dough at the two points that matter: at about 16 hours, when it should be ready to divide (clearly risen, about 1½–2 times its starting volume as common practice, domed and bubbly), and from about 20 hours on, when the balls may be ready early. Keep the balls in a lightly oiled lidded tub or on a tray under an upturned box, covered so no skin forms.
  • Prefer the fridge for the uncertain part. A plan that puts the dough in the fridge for most of the time is far less sensitive to the room, because the cold does most of the slowing. The model's cold-ferment amounts are in cold ferment pizza dough.

The table is for a lean dough: flour, water, salt, yeast and perhaps a little oil. Sugar, malted flour or old yeast shift the timing, and the range in the last column is a judgment about doughs the model does not see, not a confidence interval. For food-safety sources on dough left out at room temperature, see can pizza dough sit out overnight; a dough with perishable ingredients falls under the official two-hour rule quoted there.

Check the dough, then bake

Whatever the table says, the dough decides. At about 16 hours the dough should be risen, domed and full of small bubbles; divide it and shape the balls then. Check the balls as described above: roughly doubled, 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, flat and covered in large bubbles, they have gone too far: bake them soon, and next time use the lower end of the range or a cooler spot. If a dough that has been out all night shows no sign of life at all, why pizza dough is not rising goes through the causes, and can pizza dough sit out overnight covers what to do with a dough that has already been out.

Plan it with the calculator

The pizza dough calculator plans room-temperature doughs of 4 to 12 hours and fridge doughs of 24 to 72 hours, with the yeast in grams and a schedule worked back from dinner. It does not plan a 24-hour room-temperature dough: the amounts here come from the same model, run for a full day at one temperature. Use the table above, and if your kitchen will not hold one temperature for a day, choose the calculator's 24-hour fridge plan instead and let the cold take the uncertain hours.