Guide · Yeast
How much yeast for pizza dough
The right dose isn't a spoonful. It's a function of hours and degrees.
There is no fixed amount. It depends on two numbers: how many hours the dough ferments, and at what temperature. More time and more warmth mean less yeast. For a napoletana at 22 °C over 8 hours you need about 1.7 g of fresh yeast per kilo of flour; at 24 hours, 0.45 g. Less yeast and more time: more aroma, and a lighter crumb.
"How much yeast do I use?" might be the most-searched question about any dough. The honest answer is that a universal dose doesn't exist, and anyone who hands you one in spoonfuls is misleading you. Yeast isn't an ingredient like salt, with a fixed percentage: it's a biological engine, and its speed changes with time and temperature. A dose that's perfect in June wrecks the dough in January.
What the dose depends on
Two levers, and nothing else: the hours of fermentation and the degrees. Yeast works faster when it's warm, about three times faster for every 10 °C you add. The dough that wants a certain dose at 20 °C gets by on roughly a third of it at 30 °C, and asks for one and a half times as much in a cold 16 °C kitchen. Time does the other half of the sum: double the hours and you roughly halve the yeast.
The table below comes from the same calculation our tool uses, calibrated on practical Italian doses. The figures are grams of fresh yeast per kilo of flour.
| Temp \ Hours | 4 h | 6 h | 8 h | 12 h | 24 h | 48 h |
|---|---|---|---|---|---|---|
| 16 °C | 8.5 | 5.2 | 3.7 | 2.3 | 0.99 | 0.43 |
| 18 °C | 6.4 | 3.9 | 2.8 | 1.7 | 0.74 | 0.32 |
| 20 °C | 4.9 | 3.0 | 2.1 | 1.3 | 0.57 | 0.25 |
| 22 °C | 3.8 | 2.4 | 1.7 | 1.0 | 0.45 | 0.20 |
| 24 °C | 3.1 | 1.9 | 1.3 | 0.83 | 0.36 | 0.16 |
| 26 °C | 2.5 | 1.6 | 1.1 | 0.68 | 0.30 | 0.13 |
Computed with our tool’s time-and-temperature model. For instant dry yeast divide by 3; for active dry divide by 2–2.5 (manufacturers do not agree on a single figure).
Read it like this: find the row for your room temperature, the column for the hours you have ahead, and read off the dose. In summer, 26 °C and 8 hours, you're at about 1.1 g/kg. The same pizza in a winter kitchen at 18 °C, over the same 8 hours, wants two and a half times as much. That's not a detail: it's why your cousin's recipe never comes out the same for you.
A full 25 g cube "per kilo of flour" is grandma's recipe for same-day bread, not pizza. Across the common cases, 8 to 24 hours with the kitchen between 18 and 26 °C, the dose lands between 0.3 and 2.8 g per kilo of flour. Not 25.
Fresh, active dry or instant dry
Fresh yeast (the cake) and the two dry forms do the same job, but you don't dose them the same way: dry yeast is more concentrated, so you need far less of it. The rule of thumb, the one our tool uses too:
| If the recipe says… | Fresh | Active dry (ADY) | Instant (IDY) |
|---|---|---|---|
| 10 g | 10 g | 4–5 g | 3.3 g |
| 5 g | 5 g | 2–2.5 g | 1.7 g |
| 3 g | 3 g | 1.2–1.5 g | 1 g |
| 1 g | 1 g | 0.4–0.5 g | 0.33 g |
Instant dry yeast (IDY) is fresh ÷ 3: that is the dry-solids ratio, and manufacturers agree on it. Active dry (ADY) has no single divisor — published guidance runs from ÷2 to ÷2.5, so start at the higher dose if the yeast is not fresh. Active dry should be rehydrated in warm water (38–43 °C) before use.
In short, instant dry yeast goes in at a third of the fresh weight, active dry at 40-50%, since the makers don't agree on a single divisor. If a recipe asks for 3 g of fresh and you only have instant, use 1 g. Watch one practical difference: active dry (ADY) is meant to be rehydrated first, ten minutes in warm water at 38-43 °C (100-110 °F), while instant (IDY, the fine granules in the small sachets) goes straight into the flour. King Arthur now says the soak is optional, and with a long fermentation it probably is. Skip it and half-dead yeast is the quickest thing you'll get — that, and a dough that never gets going.
Less yeast, more time
If you remember one thing, make it this: less yeast and more time give a better pizza. With a small dose the fermentation goes slowly, and while it goes slowly the flour's enzymes get time to break down starch and soften the gluten. The result is a dough that's more fragrant, with a softer crumb and the real-bread flavour that flash rises never deliver. Load it with yeast and you get the opposite: fast and bloated but flat in taste, smelling of beer and deflating the moment it leaves the oven.
There's a limit, of course. Less yeast means more waiting, and the flour has to hold up: a weak supermarket 00 collapses before it reaches 24 hours. Long maturation needs a stronger flour, and that's a whole other story you'll find in the guide on W.
How the fridge changes things
The fridge is the friend of anyone with a job. At 4 °C (40 °F) the yeast nearly stops: in the model we use, an hour in the fridge counts for about a tenth of an hour at room temperature, which is why a dough can sit in there for 24, 48, even 72 hours without running away. The effect on the dose is blunt. Cold hours barely move the yeast figure, and they go on building aroma the whole time.
You still need a pinch of yeast to get things going: cold doesn't switch fermentation off, it puts it on idle. In the calculator you set the room-temperature hours and the fridge hours separately, and the dose adjusts itself.
The most common mistake: too much yeast
Of ten doughs that go wrong, nine had too much yeast. It's the fear that it won't rise that pushes the hand, and the result is always the same: pizza that tastes of yeast, a rim that puffs and then collapses, a flavour that tastes of nothing. When it happens, next time halve the dose and lengthen the schedule. The opposite mistake exists, but it's rarer and easier to read: if the balls are still firm and don't yield to a touch after all the planned hours, give them another hour of warmth before you stretch.
Frequently asked questions
How much yeast per kilo of flour?
It depends on hours and temperature, but for a rule of thumb: at 22 °C over 8 hours, about 1.7 g of fresh yeast per kilo, closer to 2.1 g if the room sits at 20 °C. At 12 hours you're down to 1 g, at 24 hours to 0.45 g. The table above covers the common cases.
How much dry yeast for pizza?
A third of the fresh weight if it's instant, about 40% if it's active dry. Where a recipe asks for 1.5 g of fresh, use 0.5 g instant or 0.6 g active.
Fresh or instant yeast: which is better?
They make the same pizza. Fresh is handy if you bake often and use it up; instant dry keeps for months in the cupboard and doses without dissolving. For long rises the difference is negligible, and outside Italy instant is usually the only one on the shelf.
I used too much yeast, can I fix it?
Once the dough is mixed, not much: you can move it to the fridge to slow it down and stretch it before it over-matures. The real fix is next time, with less yeast and more time.
Can I use sourdough starter?
Yes. It usually goes in at around 20% of the flour weight, and it stretches the timing a little compared with baker's yeast. The calculator has an option for both stiff and liquid starter.