About the Yeast Calculator
Understand the science behind yeast fermentation and how to use this tool to perfect your proofing schedules.
Use Cases
This calculator is designed for bakers who:
- Want to fit baking into a busy schedule by calculating exactly how much yeast is needed for a specific timeframe.
- Need to adapt a recipe for a different kitchen temperature.
- Are converting recipes between different yeast types (Instant, Active Dry, or Fresh/Cake Yeast).
- Want to experiment with long, cold fermentation (retarding) for better flavor development.
How It Works
The Biological Principle
Yeast is a living organism, and its metabolic rate (how fast it makes dough rise) is heavily dependent on temperature. As a general biological rule of thumb (derived from the Arrhenius equation), yeast activity doubles for every ~17°F (approx 10°C) increase in temperature.
The Formula
We predict the required yeast percentage using a model calibrated to real-world baking data. The core formula is:
Where K is a calibration constant based on a standard dough rising in 5 hours at 75°F with 0.096% Instant Dry Yeast.
Multi-Stage Fermentation
The calculator handles complex schedules by calculating "Effective Fermentation Hours." For example, 1 hour at 92°F counts as 2 "standard hours" at 75°F because the yeast works twice as fast. Conversely, time in the fridge (cold retard) counts for much less because yeast slows down significantly.
Yeast Types
Not all yeast is created equal. The calculator automatically applies standard conversion factors: