Brewhouse Efficiency & OG
Brewhouse or mash efficiency from a grain bill and a measured gravity, the gravity to expect at your efficiency, and the grain needed for a target OG.
Efficiency against the grains’ potential, the most the grain bill could give, the original gravity to expect at an efficiency, the factor that scales the grain bill to a target gravity, and each grain’s share.
Example: 10 lb at 37, 1 lb at 34 and 0.5 lb at 33 in 5.5 gal at 1.052 is 68 % efficiency; reaching 1.060 needs 1.154× the grain.
Points found,
points possible.
What a grain’s potential means, how efficiency compares the gravity you got with it, and which volume makes it brewhouse or mash efficiency.
Potential
A grain’s potential is the gravity points one pound would give if all its extract dissolved into one US gallon — 37 points per pound per gallon is written 37 or 1.037. It comes from the maltster’s analysis. The grain bill’s potential is the sum of weight × potential.
Efficiency
The points actually collected are (gravity − 1) × 1000 × gallons. Efficiency is that over the potential. Measured in the fermenter it is brewhouse efficiency; with the pre-boil volume and gravity it is mash efficiency, which leaves out kettle losses.
Planning
At a known efficiency the expected gravity is 1 + potential × efficiency ÷ gallons ÷ 1000, and the factor to scale every grain to hit a target is target points × gallons ÷ (potential × efficiency). Metric weights and volumes are converted with 1 lb = 0.45359237 kg and 1 US gal = 3.785411784 L.
What the numbers do not settle
Crush, water chemistry, sparge technique and mash time move efficiency; the page measures it, it does not explain it. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.