Strike Water & Mash Infusion
Strike water temperature and volume for a single-infusion mash, and the boiling water a step infusion needs, by John Palmer’s equations.
How hot the strike water must be to settle at your mash temperature, how much of it for your water-to-grain ratio, and for a step mash the water to add at a given temperature — in US or metric units.
Example: 10 lb of grain at 65 °F at 1.25 qt/lb for a 155 °F mash needs 12.5 qt of strike water at 169.4 °F; raising it to 168 °F takes 6.21 qt of 210 °F water.
Heat shared
with the grain.
How the strike temperature balances the heat in the water against the cold grain, what the constant stands for, and how a step infusion works.
Strike water
Hot water and cooler grain settle at a temperature in between. Palmer’s equation gives the water temperature for a target: Tw = (c ÷ r)(T2 − T1) + T2, with r the water-to-grain ratio, T1 the grain’s temperature and T2 the mash target. A thinner mash (larger r) needs less overshoot.
The constant
c is the grain’s heat capacity relative to water in the units used: 0.2 when the ratio is in quarts per pound, about 0.41 in litres per kilogram. Palmer notes that mash tuns differ; if your mash settles low, raise it a little — the page accepts your own value.
Step infusions
To raise a mash already at T1 to T2 with water at Tw: Wa = (T2 − T1)(c × G + Wm) ÷ (Tw − T2), with G the grain weight and Wm the water already in the mash. Each step makes the mash thinner.
What the numbers do not settle
Heat lost to a cold tun is not modelled — preheat it, or fold the loss into c. Handle near-boiling water with care. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.
SOURCES
- John J. Palmer, How to Brew — the strike water and infusion equations
Last reviewed 24 September 2026. How results are checked: How we verify.