Yeast Pitching Rate Calculator

Work out yeast pitching rate instantly with clear inputs, formula shown and shareable results.

About Yeast Pitching Rate Calculator

Pitching rate is expressed as million cells per millilitre per degree Plato: 0.75 for ales, 1.5 for lagers and up to 2 for high-gravity worts. Total cells scale with volume and gravity, then divide by viability because dead cells contribute nothing. A standard 11 gram dry yeast packet supplies roughly 200 billion viable cells.

Formulas

Pitching rate

Cells (billion) = rate x degrees Plato x volume (L)

Viability correction

Cells to pitch = cells required / viability %

Worked example

With the default values below, Yeast Pitching Rate Calculator returns Yeast Cells Required of 226.16. Change any input above and every figure here is recalculated in your browser.

Inputs used

Wort Volumeminimum 0 L: 20 L
Original Gravityaccepts 0.9–1.2: 1.055
Pitching Rateminimum 0.01 million cells per mL per degree Plato: 0.75 million cells per mL per degree Plato
Yeast Viabilityaccepts 1–100 %: 90 %

Results

Yeast Cells Required: 226.16
Viable Cells Needed: 203.54
Wort Gravity In Plato: 13.570
Equivalent 11 g Dry Yeast Packets: 2.262

Step by step

1Values used
2Pitching rate
3Viability correction
4Yeast Cells Required= 226.16
5Viable Cells Needed= 203.54
6Wort Gravity In Plato= 13.570
7Equivalent 11 g Dry Yeast Packets= 2.262

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What happens if the pitch is too low?

A long lag phase, excessive ester and fusel alcohol production, stuck fermentation and greater risk of contamination taking hold. Under-pitching is the commonest fermentation fault.

Can over-pitching cause problems?

Yes, though less often. Very high pitch rates suppress ester formation, give a thinner flavour profile, and can cause premature yeast autolysis and a rubbery off-flavour.