Mash Water Calculator
Enter grain bill and target mash temp to find water volumes and strike temperature.
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Mash Water Calculations for All-Grain Brewing
All-grain brewing requires precise water volumes. The strike water must be hotter than your target mash temperature because the cold grain will cool it down.
Standard mash thickness is 1.25–1.5 quarts per pound of grain. Thinner mashes (1.5+) are more forgiving; thicker mashes (1.0–1.25) produce more body.
The liquor-to-grist ratio is the volume of water per pound of grain in the mash. A ratio of 1.25–1.5 quarts per pound (2.6–3.1 liters per kg) is standard for single-infusion mashes. Thinner mashes (higher ratio) favor faster fermentability; thicker mashes (lower ratio) can improve body and head retention.
Mash water volume = grain weight (lb) × ratio (qt/lb) / 4 (to convert quarts to gallons). For 10 lb of grain at 1.33 qt/lb: 10 × 1.33 / 4 = 3.33 gallons. Grain absorbs roughly 0.125 gallons per pound, so pre-boil runoff from this mash is approximately 3.33 − 1.25 = 2.08 gallons (before sparge addition).
Strike water temperature must account for the temperature drop when cold grain is added. For a target mash temperature of 152°F with grain at 65°F: strike temp ≈ 152 + (0.2/ratio) × (152 − 65) = roughly 163°F at 1.33 qt/lb. This calculator uses a standard thermal mass formula.
Mash temperature affects fermentability: 148–152°F produces more fermentable (drier) wort; 154–158°F produces fuller body with more residual dextrins. Most ales target 150–154°F.
See also: ABV Calculator · Priming Sugar Calculator