Instant Yeast vs Active Dry vs Fresh Yeast for Pizza Dough

Active dry is 1.25 times the instant weight. Fresh is 3 times the instant weight. Those two numbers are the reason this page exists, and if you are mid-mix with the wrong jar in your hand, that is the whole answer: 2 g of instant dry yeast is 2.5 g of active dry or 6 g of fresh. Everything below is about why the factors are what they are, whether each one needs proofing, and how the three behave differently over a long cold ferment.

What is the difference between instant, active dry and fresh yeast?

All three are the same organism, Saccharomyces cerevisiae, sold at three different moisture levels and particle sizes. That is genuinely the entire difference, and every practical consequence falls out of it.

Instant dry yeast, sometimes labelled fast-acting, rapid-rise or lievito secco, is dried to roughly 5 percent moisture and milled into fine particles. The particles are small enough to hydrate on contact with dough, so it goes straight into the flour with no separate step. This is the default for pizza and the type every formula on this site is written in.

Active dry yeast is dried to a similar moisture level but left in much larger granules, and the outer layer of cells on each granule is dead. That dead layer is a protective shell: it makes the yeast more stable in storage and it means a given weight contains fewer living cells than the same weight of instant. Hence the 1.25 factor. The granules are also too large to dissolve reliably in a stiff dough, which is why it benefits from being woken up in warm water first.

Fresh yeast, also called cake yeast or compressed yeast, is not dried at all. It is a moist block roughly 70 percent water, which is most of where the 3x factor comes from: you are buying mainly water, so you need three times the weight to get a comparable cell count. It crumbles, it smells strongly of yeast, and it has a shelf life measured in weeks rather than years.

A plain definition sentence before the arithmetic, because everything below depends on it: in baker's percentage every ingredient is expressed as a percentage of the total flour weight, and flour is always 100 percent. Yeast percentages on this site are always percentages of flour, never of total dough. The mechanics are in the baker's percentage guide and the standard ranges are on the percentage chart.

What are the exact conversion factors?

The table below is built on one recipe so the numbers can be checked against each other: four 250 g balls, so 1,000 g of total dough, at 65 percent hydration and 2.5 percent salt. At 0.3 percent instant dry yeast the total percentage is 167.8, so the flour is 1,000 divided by 1.678, which is 595.9 g. Water is 387.3 g, salt is 14.9 g and yeast is 1.8 g. Those four add back to 1,000 g, and that check is worth doing on any dough calculation you are handed.

The 0.1 percent column is the same recipe set up for a 48 hour cold ferment. There the total percentage is 167.6, the flour is 596.7 g, and the yeast falls to 0.6 g.

So in the standard build, 1.8 g of instant dry yeast becomes 2.2 g of active dry or 5.4 g of fresh. Nothing else in the recipe changes when you convert, with one exception worth knowing: fresh yeast carries its own water, so at large quantities you can subtract that water from the recipe. At pizza doses it is negligible. Five grams of fresh yeast brings about 3.5 g of water into a dough already carrying nearly 390 g of it, which moves hydration by roughly half a percentage point and is not worth adjusting for.

Weighing is not optional at these quantities. A 1.8 g target and a 2.2 g target are 0.4 g apart, which no spoon can resolve, and the difference between 0.6 g and 1.8 g is the difference between a dough that is perfect on day two and one that is collapsed and blistered. A 0.1 g resolution kitchen scale is the cheapest large improvement available in home pizza, and it is the tool this entire page assumes.

What if I just want the conversion, without the recipe?

Read across from whatever the recipe calls for. Every figure is rounded to 0.1 g, which is the resolution a domestic scale can actually read.

The teaspoon column is there to be argued with rather than used. A teaspoon of instant dry yeast weighs roughly 3.1 g, which is where the familiar 7 g sachet and its stated 2 and a quarter teaspoons come from. A teaspoon of active dry weighs less, because the granules pack with more air between them, and fresh yeast cannot be spooned at all. Any recipe that specifies yeast by volume across all three types is guessing, and at pizza quantities the guess is large enough to change the schedule by hours. The way to read a formula that mixes units is covered in the guide to reading a dough recipe.

Which ones need proofing in water, and which do not?

Proofing means dissolving yeast in warm water with a pinch of sugar and waiting for it to foam. It does two things: it rehydrates the yeast, and it proves the yeast is alive. Only one of those is required, and it depends on the type.

Instant dry yeast does not need it. The particles are fine enough to take up water from the dough itself within the first minute of mixing. Whisk it into the flour, add the water, carry on. There is no penalty for proofing it anyway other than five minutes, and no benefit either.

Active dry yeast genuinely benefits. Give it 5 to 10 minutes in water at 100 to 110F. Undissolved granules in a stiff dough hydrate slowly and unevenly, and the result is a sluggish first hour followed by patchy activity. Water hotter than about 120F starts killing yeast, so this is a case where a thermometer earns its place. An instant-read probe thermometer reads both the proofing water and, more importantly, the final dough temperature, which is the number that actually controls fermentation and the one almost nobody measures.

Fresh yeast must be dissolved. Crumble it into the recipe water and stir until the water goes cloudy and no lumps remain. Fresh yeast dropped into flour as a lump stays a lump, and you will find pale dense spots in the finished crust. Use the recipe water at normal temperature rather than warm water, since fresh yeast dissolves easily and does not need coaxing.

One rule applies to all three: salt never goes into the proofing water. Salt draws water out of yeast cells and slows them sharply, so it belongs in the flour or in the mix, never in a concentrated solution with the yeast. That is the same reason salt stays out of a poolish or a biga, as explained in the poolish vs biga comparison.

How do the three behave over a 24 to 72 hour cold ferment?

Far more similarly than the internet suggests. Over a long cold ferment the variable that dominates is temperature, not yeast brand or type. As a working approximation, yeast activity roughly doubles for every 17F, about 9C, that dough temperature rises, so a dough that proofs in two hours at 75F takes roughly four at 58F. That relationship, not the yeast type, is what sets your schedule.

Within that, the differences that do show up are these. Instant dry is the most predictable because the dose is easy to hit accurately and the product is consistent from jar to jar. Active dry has a slightly slower start, since it takes longer to fully rehydrate, and that lag is invisible by hour six of a 48 hour schedule. Fresh yeast starts fastest of the three and some bakers find it produces a slightly sweeter, more aromatic crumb, though it is also the one most likely to be past its best without you knowing.

All gram figures assume the same 1,000 g dough at 65 percent hydration and 2.5 percent salt, so the flour sits between 595 and 597 g depending on the yeast percentage. That variation is a fraction of a gram and can be ignored. Scale the whole table by multiplying: a 2,000 g batch doubles every figure, a 500 g batch halves them. The proof time calculator will run the schedule for any temperature and the fermentation time by temperature chart maps out how the two trade against each other.

The 72 hour row is where the yeast type genuinely starts to matter, but not for the reason people expect. At 0.3 g of instant you are at the resolution limit of most domestic scales, so switching to fresh yeast at 0.9 g is a legitimate accuracy trick: three times the weight is three times easier to weigh. The alternative is to mix a larger batch, which is usually the more sensible move. Long cold schedules and their failure modes are covered in the cold fermentation guide.

How long does each type keep, and how should it be stored?

Yeast does not fail suddenly, it fades. A packet that is half dead does not refuse to work, it doubles your proof times, which is why a mysterious schedule change is nearly always a storage problem rather than a recipe problem.

Two habits fix almost all yeast storage problems. Decant a large vacuum pack into a small airtight jar and keep the jar in the freezer, taking out only what you need. Do not scoop from a jar with a wet spoon or over a steaming bowl, because moisture is what kills stored dry yeast rather than time. Fresh yeast is the exception to all of this: buy it for a specific bake, use it within two to three weeks, and accept that it does not sit in a fridge waiting for you.

If you suspect a packet is tired, test it rather than guessing. Stir 3 g into 100 g of water at about 105F with a pinch of sugar and wait 10 minutes. Living yeast produces a visible foam cap. Nothing after 10 minutes means the packet is finished, and no amount of extra proof time will rescue the dough you were about to make with it.

What about sourdough as a fourth option?

Sourdough belongs in the conversation, but it does not belong in the conversion table, and pretending otherwise is how people ruin a batch. A starter is not a concentrated packet of one organism, it is a living culture of wild yeasts and lactic acid bacteria carried in a flour and water medium. There is no factor that converts 1.8 g of instant dry yeast into a weight of starter, because the two are not the same kind of ingredient.

Three things change when you switch. First, the starter brings flour and water into the recipe, so the hydration arithmetic has to be redone: 100 g of a 100 percent hydration starter adds 50 g of flour and 50 g of water to the totals, and if you ignore that, your 65 percent dough is not 65 percent any more. Second, the bacteria produce lactic and acetic acid, which condition the gluten and change how the dough handles, generally making it more extensible and more fragile at the same time. Third, the timing is set by the state of your starter rather than by a percentage, so a schedule that worked last week may not work this week.

A typical pizza starting point is 10 to 20 percent of the flour weight carried as starter, which for the 595.9 g build means roughly 60 to 120 g, with a bulk and ball schedule that runs considerably longer than a commercial-yeast dough. Treat that as a new formula to be built from scratch, not as a swap, and keep the first few batches on a graduated straight-sided container so you can read the rise as a percentage instead of guessing at it.

Which yeast should you actually buy for pizza?

Taking a side for each situation rather than hedging.

You want one jar that handles everything: buy instant dry yeast. It needs no proofing, it keeps a year in the freezer, it is the type every formula on this site is written in, and it is the easiest to dose accurately at the fractions of a gram a cold ferment needs. This is the correct answer for almost everybody.

You already own active dry and do not want to buy anything: use it, at 1.25x. Proof it for 5 to 10 minutes in 100 to 110F water first and the result is indistinguishable in a finished pizza. There is no quality reason to throw it away.

You have access to fresh yeast and bake on a fixed schedule: use fresh, at 3x. It is the traditional choice in Naples, it is easy to weigh because the quantities are larger, and some bakers prefer the aroma. The catch is entirely logistical: two to three weeks of shelf life means planning.

You are running 72 hour cold ferments and your scale reads to 1 g: use fresh, or mix a bigger batch. Weighing 0.3 g on a scale with 1 g resolution is not weighing, it is hoping. Three times the weight is three times the precision for free.

You want sourdough flavour: build a sourdough formula, do not substitute. Start from a recipe written for a starter, and expect a season of calibration rather than one bake.

What goes wrong when the conversion is done badly?

Almost every yeast failure in pizza is a dose failure, and the symptoms are specific enough to diagnose from the finished crust.

Too much yeast, which is what happens when someone swaps fresh for instant at 1 to 1 without dividing by three, produces a dough that races. It over proofs in the fridge, goes slack and sticky, spreads instead of holding a ball, and tastes distinctly of alcohol or beer. The crust bakes with big irregular bubbles and a rim that collapses. Nothing about the bake fixes it, because the damage happened before the oven was lit.

Too little yeast, which is what happens when someone swaps instant for fresh at 1 to 1, produces a dough that never really wakes up. The balls stay tight and springy, they snap back when you try to open them, and the finished crust is dense with a low, bready rim and no blistering. This one is at least recoverable: give it more time, or move it somewhere warmer, and it will usually come good.

Storing the balls somewhere you can see them is the fastest way to catch either problem before the oven is hot. Straight-sided proofing boxes or a graduated proofing container turn "has it doubled" into a reading rather than a guess, and a bench scraper is what gets a slack over proofed ball off the bench without tearing it further. Every symptom above, with its fix, is on the pizza dough troubleshooting chart.

One last thing that is not the yeast fault. Flour choice interacts with dose, because a stronger flour tolerates a longer ferment before the gluten gives up. A bread flour at around 12.7 percent protein holds a 48 hour cold ferment comfortably, and a 00 flour formulated for long fermentation holds longer still. If your dough consistently collapses at 48 hours on the correct yeast dose, look at the flour before you look at the jar. The flour protein chart lists the ranges, and the dough hydration calculator will rebuild the whole formula around whichever flour you settle on.