Free Yeast Percentage calculator with clear step-by-step results.
Yeast quantity is inversely proportional to proving time and strongly temperature dependent - fermentation rate roughly doubles for every 8 C rise. Starting from a reference of 1.2% instant yeast for a two-hour prove at 24 C, both adjustments are applied before converting to the yeast type you actually have.
Yeast percentage
Instant % = 1.2% x (2 / proving hours) x 2^((24 - dough temp) / 8)
Type conversion
Active dried = instant x 1.25; fresh compressed = instant x 3
Yes, and the bread is usually better for it. A cold overnight prove at 0.2-0.3% instant yeast develops far more flavour than a fast warm prove at 2%.
Fresh compressed yeast is around 70% water while instant dried is under 8%, so you need roughly three times the mass for the same live cell count.