Mash Efficiency Calculator

It's the maximum gravity points one pound of that malt could theoretically contribute to one gallon of wort if extraction were perfect — 37 for 2-row, 36 for pilsner, and 38 for wheat in this calculator's defaults, reflecting each malt's typical starch and enzyme content. Multiplying it by your grain weight gives the ceiling (Maximum Possible Points) that your actual extraction is measured against.

Actual Points Extracted is calculated as pre-boil gravity times pre-boil volume, so it captures exactly how much sugar you collected before any boil-off concentrates the wort further. Using your final post-boil volume instead would overstate the concentration relative to the water actually present at that measurement, so pre-boil volume needs to be measured after all runnings are collected but before boiling starts.

Since this is a single-point measurement rather than a full mash model, it can't diagnose the cause directly, but a coarse crush, insufficient mash time, channeling during sparge, or a mash that's too thick are the most common culprits for most home-scale systems, which typically land between 65-85% efficiency. Because the calculation has no way to distinguish a real efficiency drop from a volume-measurement error, double-check your pre-boil volume reading first.

Points Per Pound is your actual extraction rate — actual points extracted divided by grain weight — independent of what your theoretical maximum was set to. It's useful for comparing extraction consistency across recipes that use different grain bills or different Max Potential Points values, where the efficiency percentage alone might look similar but be measuring against a different ceiling.