Swapping yeast types
Fresh yeast is about two-thirds water, so dry yeast is much stronger by weight. The usual ratios are:
- Fresh yeast → active dry: use 40% (multiply by 0.4)
- Fresh yeast → instant: use one third (multiply by 0.33)
- Active dry → instant: use about 25% less
A standard packet of dry yeast holds 7 g (¼ oz, 2 ¼ teaspoons) and replaces about 17–21 g of fresh yeast, roughly half a European 42 g cube.
How to use each type
Active dry yeast is best dissolved in warm water (around 38 °C / 100 °F) for 5–10 minutes before mixing. Instant yeast can go straight into the flour. Fresh yeast is crumbled into lukewarm liquid and keeps about two weeks in the fridge.