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What does the Yeast scaling calculate?
How much yeast is needed when the dough batch changes size? This calculator uses original flour weight, original yeast weight, and new flour weight to estimate yeast for a resized dough immediately in your browser.
With the values currently entered, the result is 0.4 oz — scaled yeast amount. It also shows batch scale factor, and yeast as flour percentage.
How to use the Yeast scaling
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Original flour weight — entered in g
- Original yeast weight — entered in g
- New flour weight — entered in g
Yeast scaling formula
Original yeast × new flour ÷ original flour
Assumptions
- Fermentation time and temperature stay the same.
- The same yeast type is used.
Practical guide
Yeast scaling example and edge cases
How much yeast is needed when the dough batch changes size? Let's use a concrete example, then look at the assumptions that can move the answer.
Example: A practical yeast scaling scenario
For this example, use original flour weight of 500 g, original yeast weight of 5 g, and new flour weight of 1,200 g. These are starting values, so replace them with numbers that match your situation.
- Original flour weight
- 500 g
- Original yeast weight
- 5 g
- New flour weight
- 1,200 g
Calculated result0.4 ozscaled yeast amount
Start with scaled yeast amount. Then check batch scale factor, and yeast as flour percentage to understand what sits behind the main result.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the main result first. The supporting figures for batch scale factor, and yeast as flour percentage explain how the estimate is built.
- The method is Original yeast × new flour ÷ original flour. Keep the units consistent and use values from the same time period.
Edge cases worth checking
When original flour weight is unusual
Fermentation time and temperature stay the same. Double-check this input before relying on the result.
When new flour weight is uncertain
The same yeast type is used. Run a lower and higher value to see a useful range.
What changes the result most
Original flour weight
Change original flour weight on its own first. This shows how strongly it affects the answer.
Original yeast weight
Change original yeast weight on its own first. This shows how strongly it affects the answer.
New flour weight
Change new flour weight on its own first. This shows how strongly it affects the answer.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Original flour weight: 10% lower
450 g0.5 ozscaled yeast amount
Original flour weight: 10% higher
550 g0.4 ozscaled yeast amount
Original yeast weight: 10% higher
6 g0.5 ozscaled yeast amount
Common mistakes
Check original flour weight
Fermentation time and temperature stay the same. Make sure this matches the number you enter.
Keep new flour weight consistent
The same yeast type is used. Use the same units and time period throughout the calculation.
Do not rely on one yeast scaling scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
How much yeast is needed when the dough batch changes size?
Taste, ingredient behavior, food safety, and equipment can require adjustments.