You can use fresh yeast instead of active dry yeast at a ratio of 21 g fresh yeast per 7 g packet of active dry yeast. That is the conversion, and it is a simple one — but yeast is a living ingredient, and the swap changes more than the number on the packet. It changes how fast the dough rises, how much flavour the fermentation adds, and how you handle the dough from mixing to baking. Get the amount right and the handling wrong, and the bread will still disappoint; get both right and the swap is invisible.
Yeast types differ in granule size and activation; amounts are not 1:1 by weight, but packets are standardised. This page gives you the conversion table for every amount you are likely to meet, three worked examples with real numbers, what changes in rise time and flavour, and the recipes where you should not substitute at all.
The ratio, in a table
The table below converts active dry yeast to fresh yeast for the amounts you are most likely to meet. The rule is always the same: 21 g fresh yeast per 7 g packet of active dry yeast.
| Active dry yeast | Fresh yeast to use | Notes |
|---|---|---|
| 1/4 packet (1 3/4 g) | about 5 1/4 g fresh yeast | Crumble it into the liquid and dissolve before mixing. |
| 1/2 packet (3 1/2 g) | about 10 1/2 g fresh yeast | Crumble it into the liquid and dissolve before mixing. |
| 1 packet (7 g) | about 21 g fresh yeast | Crumble it into the liquid and dissolve before mixing. |
| 1 1/2 packets (10 1/2 g) | about 31 1/2 g fresh yeast | Crumble it into the liquid and dissolve before mixing. |
| 2 packets (14 g) | about 42 g fresh yeast | Crumble it into the liquid and dissolve before mixing. |
By weight, one cup of active dry yeast is about 144 g (King Arthur Baking, spooned and levelled). Our density table does not list a grams-per-cup figure for fresh yeast, so no weight is given for it here — measure it by volume and, if the recipe is sensitive, weigh a trial cup yourself and note the number. All weights here are approximate; verify with a kitchen scale when the bake matters.
King Arthur lists instant yeast at 144 g per cup; active dry yeast is sold in 7 g packets and has a similar density. We use 144 g with medium confidence.
Worked examples
Example 1: A focaccia
Focaccia is a forgiving flatbread and a good place to try a yeast swap. A recipe calls for 1 packet (7 g) of active dry yeast. Using the ratio, that becomes about 21 g fresh yeast. Crumble the fresh yeast into the warm liquid and stir until it dissolves before adding the flour. Fresh yeast works at about the same speed as active dry yeast, so the rise times in the recipe still roughly apply — judge the dough by size and feel, as always. Mix the dough — it should be wet and sticky — let it rise until doubled, then press it into an oiled tray, dimple it with your fingers, drizzle with olive oil and bake until golden. The open crumb and the olive oil carry the bread, and the swap's flavour difference is barely noticeable. If the rise is slower than the recipe says, give it more time: focaccia is patient, and an extra half hour only improves it.
Example 2: A sandwich loaf
A sandwich loaf is the classic test of a yeast swap. A recipe calls for 1 packet (7 g) of active dry yeast. Using the ratio, that becomes about 21 g fresh yeast. Crumble the fresh yeast into the warm liquid and stir until it dissolves before adding the flour. Fresh yeast works at about the same speed as active dry yeast, so the rise times in the recipe still roughly apply — judge the dough by size and feel, as always. Mix the dough, knead until smooth and elastic, then let it rise until doubled — judge by the dough, not the clock, because the rise time changes with the swap. Shape the loaf, let it rise again until it crowns the tin, and bake as usual. The loaf will be a little different in flavour and a little different in crumb, but a sandwich loaf made with this swap is still a good sandwich loaf.
Example 3: A pizza dough
Pizza dough is a forgiving place to try a yeast swap, because the dough is simple and the toppings carry the flavour. A recipe calls for 1 packet (7 g) of active dry yeast. Using the ratio, that becomes about 21 g fresh yeast. Crumble the fresh yeast into the warm liquid and stir until it dissolves before adding the flour. Fresh yeast works at about the same speed as active dry yeast, so the rise times in the recipe still roughly apply — judge the dough by size and feel, as always. Mix and knead the dough, let it rise until doubled, then divide and stretch it out. If the dough resists stretching, let it rest for ten minutes and try again — a rested dough stretches much more easily. Top and bake at the hottest oven you have. The crust will be a little different in flavour and chew, but with good toppings nobody will notice the swap.
What changes in the result
Two things change when you swap fresh yeast for active dry yeast: the speed of the rise and the flavour of the bread. The speed changes because different yeasts work at different rates, and a sourdough starter works far more slowly than a packet of dried yeast. That means the rise times in your recipe no longer apply — you have to judge the dough by look and feel instead. The flavour changes because a longer, slower fermentation produces more of the acids and alcohols that give bread its character. A bread made with a slow ferment tastes more complex than one made with a fast ferment, and that is usually an improvement, not a problem.
When not to substitute
Do not use baking powder or soda as a yeast substitute in bread — the rise and flavour are completely different. In practice that means: do not try to replace yeast with baking powder or baking soda in a bread recipe — chemical leaveners work in minutes and cannot reproduce a slow ferment, so the bread will be dense and will taste of soda. Do not use this swap in a bread-machine recipe written for a specific yeast without checking the machine's instructions, because the timing cycles assume a particular rise speed. And do not rush the rise: if the dough has not doubled, it is not ready, whatever the clock says. If the bread matters — a loaf for guests, a bake you are selling — test the swap once in a small batch first.
Practical guidance
Store yeast properly and it will last: dried yeast keeps for months in a cool, dry cupboard and longer in the fridge once opened, while fresh yeast keeps for about two weeks in the fridge and should be used before it darkens or dries out. Test dried yeast before you commit a whole batch to it — dissolve it in warm water (about 40°C, comfortably warm to the touch, not hot) with a pinch of sugar and wait ten minutes. If it foams, it is alive; if nothing happens, it is dead, and no amount of waiting will save the dough. And remember that water hotter than about 50°C kills yeast outright, which is the most common reason a dough never rises.
All conversions on this page are approximate. A kitchen scale is the most reliable tool you own: weigh the substitute, note the number that works for your recipe, and use it next time. If a bake matters — a birthday cake, a loaf for guests — test the swap first in a small, forgiving recipe before you commit to the important one.
Frequently asked questions
How much fresh yeast do I use instead of active dry yeast?
Use about 21 g fresh yeast — that is the ratio 21 g fresh yeast per 7 g packet of active dry yeast applied to one packet. All amounts on this page are approximate, so if the bake is sensitive, weigh the substitute and note your own number for next time.
Do I need to proof fresh yeast before using it?
It depends on the yeast. Active dry yeast should be dissolved in warm water first; instant yeast can go straight into the flour. Fresh yeast should be crumbled into the liquid and dissolved before mixing. A sourdough starter needs no proofing, but it must be active — bubbly and doubling within a few hours of feeding — before you use it. If you are unsure, proof it: ten minutes in warm water with a pinch of sugar will tell you whether the yeast is alive.
Will the bread rise faster or slower with fresh yeast?
That is the main thing that changes. Yeast types differ in granule size and activation; amounts are not 1:1 by weight, but packets are standardised. The rise times in your recipe no longer apply, so judge the dough by look and feel: it should roughly double in size, and a gentle poke with a floured finger should leave a dent that fills back slowly. If the dough is slow, be patient — warmth helps more than extra yeast, which can make the bread taste yeasty and collapse in the oven.
Can I use fresh yeast in a bread machine?
Check the machine's instructions first. Bread machines run on fixed timing cycles that assume a particular rise speed, so a slower or faster yeast can throw the cycle off — the bread may be under-risen or over-risen when the bake cycle starts. If your machine has a custom or sourdough cycle, use it; if it does not, the swap is safer in a hand-mixed loaf where you control the timing.
Does fresh yeast change the flavour of the bread?
Yes, and usually for the better. A slower ferment produces more of the acids and alcohols that give bread its character, so a loaf made with a slow yeast or a starter tastes more complex than one made with a fast yeast. A faster yeast gives a cleaner, milder flavour. Neither is wrong — it is a matter of what you want the bread to taste like. For a sandwich loaf, mild is fine; for a rustic loaf, complex is better.