Homebrewing Efficiency Calculator
Calculate your homebrew mash efficiency and brewhouse efficiency.
Know how much fermentable sugar you extracted and how to improve your yield.
Homebrew efficiency measures how well you extract fermentable sugars from grain during the mash. Higher efficiency means more sugar (and therefore more alcohol) from the same amount of grain.
Two key efficiency numbers:
- Mash efficiency — sugar extracted from the grain into the wort
- Brewhouse efficiency — sugar that actually makes it into the fermenter (accounts for losses)
The gravity point system:
Instead of working directly with specific gravity (SG), brewers use gravity points:
Gravity Points = (SG - 1) × 1000
Example: SG of 1.052 = 52 gravity points
Potential extract by grain type:
Each pound of grain has a maximum potential extract (in gravity points per pound per gallon):
| Grain Type | Potential (PPG) | Typical |
|---|---|---|
| 2-row pale malt | 38 PPG | Most common base malt |
| 6-row pale malt | 35 PPG | Lower extract than 2-row |
| Pilsner malt | 37 PPG | European lagers |
| Munich malt | 35 PPG | Color and flavor |
| Crystal / Caramel malt | 34 PPG | Sweetness and color |
| Wheat malt | 39 PPG | Hefeweizens, wheat beers |
| Oats (flaked) | 36 PPG | Body, haziness |
| Roasted barley | 25 PPG | Stouts, color |
Brewhouse efficiency formula:
Efficiency (%) = (Measured Gravity Points × Batch Volume) ÷ (Sum of theoretical max gravity points from all grains) × 100
Or simplified when measuring pre-boil gravity:
Efficiency (%) = (Actual OG - 1) × 1000 × Batch Volume (gal) ÷ (Grain Weight (lbs) × Potential PPG) × 100
Typical efficiency ranges:
| System Type | Typical Efficiency |
|---|---|
| Extract brewing | N/A (uses pre-made extract) |
| Partial mash | 55–70% |
| All-grain (BIAB) | 65–80% |
| All-grain (3-vessel) | 70–85% |
| Professional brewery | 85–95% |
What affects efficiency:
- Crush quality — finer crush = more sugar extracted (but can clog a false bottom)
- Mash temperature — 148–158°F (64–70°C) for standard conversion
- Mash time — minimum 60 minutes for full conversion
- Water-to-grain ratio — thinner mashes typically extract slightly more efficiently
- Sparge technique — fly sparging extracts more than batch sparging
- Grain freshness — old, stale grain has lower potential
Improving low efficiency:
- Crush grain finer (but not flour-fine for traditional setups)
- Ensure mash temperature stays stable
- Extend mash to 90 minutes
- Stir the mash gently every 15 minutes
- Check for dough balls in the mash — pockets of dry grain kill efficiency