Beer color (SRM) calculator
The standard Morey estimate used across brewing software: grain weight × color per gallon gives malt color units, and SRM follows a power law from there.
How it works
Malt color units are the sum of (weight in pounds × color in °Lovibond) divided by batch volume in gallons. Dan Morey's fit, SRM = 1.4922 × MCU0.6859, corrects for the fact that perceived color rises more slowly than pigment concentration. EBC is simply 1.97 × SRM.
FAQ
What's the difference between SRM, EBC, and Lovibond?
SRM and EBC both measure finished beer color (EBC ≈ 1.97 × SRM); Lovibond rates malt color. For malts, EBC ≈ 2.65 × °L − 1.2.
Why does the Morey equation cap MCU at 167?
Beyond that, color measurements saturate. The beer is effectively opaque black, and the power-law fit was derived from data below that ceiling.
How accurate is the estimate?
Within a couple of SRM for typical beers. Boil vigor, kettle caramelization, pH, and malt lot variation all shift real color, so treat it as a good estimate rather than a measurement.
Does late-addition or steeped grain count?
For color, yes. Everything that ends up in the kettle contributes. (Mash pH is a different question: grains steeped outside the mash don't affect it, which the full calculator models separately.)
More water tools
Daniel Morey, "Approximating SRM Beer Color", the standard conversion across brewing software. Malt colors vary by lot; use your malt analysis where you have it.