Use cases
This calculator is designed for bakers who:
- Want to fit baking into a busy schedule by calculating how much yeast fits a chosen timeframe.
- Need to adapt a recipe for a different kitchen temperature.
- Are converting between Instant, Active Dry, or Fresh (cake) yeast.
- Want to combine warm bulk fermentation with a long cold retard in separate stages.
How it works
Yeast activity doubles roughly every 10–12°F rise in temperature. The calculator uses a temperature-dependent rate model calibrated for baker's yeast to compute effective fermentation time across all your stages.
When you add multiple stages (e.g. 4 hours at 72°F followed by 24 hours at 39°F), the calculator accumulates the total progress toward full proof and calculates the exact yeast percentage needed to reach 100% completion.
Yeast conversion ratios
Standard commercial yeast conversions relative to Instant Dry Yeast (IDY = 1.0):
| Yeast Type | Ratio vs IDY | Notes |
|---|---|---|
| Instant Dry (IDY) | 1.00× | Mix directly with flour |
| Active Dry (ADY) | 1.25× | Rehydrate in warm water first |
| Fresh / Cake Yeast | 3.00× | Crumble into liquids |