Skip to main content

🧫 Yeast Pitch Rate Calculator

Calculate the right amount of yeast for healthy fermentation

Proper yeast pitching is critical for healthy fermentation. Too little yeast leads to stressed fermentation, off-flavors, and stalled batches. Too much can strip flavor. Use this calculator to determine exactly how many yeast cells you need.

Lagers and high-gravity beers need more yeast
Final volume into fermenter
Higher gravity = more yeast needed

📚 Understanding Pitch Rates

Pitch rate is the number of yeast cells added per milliliter of wort per degree Plato. Proper pitching ensures healthy fermentation, clean flavors, and predictable results.

Standard Pitch Rates:

  • Ale (Standard Gravity): 0.75 million cells/mL/°P
  • Ale (High Gravity >1.060): 1.0 million cells/mL/°P
  • Lager (Standard Gravity): 1.5 million cells/mL/°P
  • Lager (High Gravity >1.060): 2.0 million cells/mL/°P

Why Pitch Rate Matters:

  • Under-pitching risks: Stressed yeast, long lag times, off-flavors, stalled fermentation
  • Over-pitching risks: Less ester production, thin/bland flavor profile, autolysis
  • Proper pitching: Clean fermentation, consistent results, healthy yeast

Yeast Package Cell Counts:

Dry Yeast (11.5g packet):
  • ~200 billion cells when fresh
  • Viability remains high for months
  • No starter needed for most beers
  • Rehydrate for best results
Liquid Yeast (Wyeast/White Labs):
  • ~100 billion cells when fresh (manufacture date)
  • Loses ~20% viability per month
  • Often needs starter for >1.050 beers
  • More strain variety available

When You Need a Starter:

  • Old liquid yeast: More than 1 month past manufacture date
  • High gravity: OG above 1.060 with single vial
  • Lagers: Need 2x the cells of ales
  • Single vial insufficient: Calculator shows >1 vial needed

Starter Size Guidelines:

  • 1L starter: Grows ~100B cells to ~200B cells
  • 2L starter: Grows ~100B cells to ~350B cells
  • 2-step starter: Can grow 100B to 500B+ cells
  • Stir plate: Increases cell growth by 2-3x vs static starter

Yeast Viability Over Time:

Age (Liquid Yeast) Estimated Viability
Fresh (manufacture date) 100% (~100B cells)
1 month old ~80% (~80B cells)
2 months old ~64% (~64B cells)
3 months old ~51% (~51B cells)
6 months old ~26% (~26B cells)

Tips for Healthy Fermentation:

  • Buy fresh yeast or make a starter
  • Store yeast cold (35-40°F) until use
  • Rehydrate dry yeast in warm water (95-105°F)
  • Aerate wort well before pitching (8-12 ppm oxygen)
  • Pitch at proper temperature for strain
  • Consider yeast nutrients for high-gravity beers
  • Save and reuse healthy yeast from previous batches

Alternative: Yeast Washing & Banking:

Save money by harvesting yeast from fermenters. One batch can provide enough healthy yeast for 5-10 future batches when properly stored. Learn proper yeast washing and banking techniques to build your own yeast library.