How it's calculated
new amount = original amount × (target factor ÷ source factor)
original amount = grams of the yeast you have, factors are per-type strength constants (fresh, active dry, instant). The ratio rescales the weight when swapping yeast types.
Common values
| Fresh | Active Dry | Instant |
|---|---|---|
| 10 g | 4 g | 3.3 g |
| 25 g | 10 g | 8.25 g |
| 42 g | 16.8 g | 13.9 g |
Common questions
Can I swap instant for active dry?
Yes. Use about 25 percent less instant than active dry, and you can usually skip the proofing step since instant yeast mixes straight into dry ingredients.
Why is fresh yeast measured by a larger weight?
Fresh yeast holds a lot of moisture, so it weighs more for the same leavening power. Dry forms are concentrated, so you need less.