Strike Water Temperature Calculator
How hot to heat strike water so the mash lands on target, plus the volume needed.
What it does
All grain brewing lives or dies at dough in. Pour water too cool and the mash enzymes underperform; too hot and you lock in the wrong sugars. The strike temperature is the water temperature that lands the whole mash on your target once the grain has absorbed its share of the heat.
The tool above takes the grain bill, the water to grain ratio, the grain temperature, and the mash target. It returns the strike water temperature, the strike volume, and a warning if the target would demand boiling water.
The defaults mash 10 pounds of grain at 1.25 quarts per pound for a 152 F target with grain at 65 F: heat 3.13 gallons to 165.9 F, dough in, and stir to settle at target.
The heat balance follows the brewing literature's standard treatment: Brew Your Own's water arithmetic for volumes and ratios, and its mash heat article for the energy balance where malt takes about 0.4 BTU per pound per degree against water's 1.0, which together give the familiar 0.2 over the ratio rule.
How to use
- Pick imperial or metric units.
- Enter your total grain bill weight.
- Enter the water to grain ratio; 1.25 to 1.5 qt/lb is typical.
- Enter the grain temperature, often room temperature.
- Enter the mash target temperature you brewed the recipe around.
- Add a tun allowance if your mash tun is cold.
- Heat the water to the strike temperature, then dough in and stir.
Formula
- R
- Water to grain ratio: quarts per pound or liters per kilogram.
- 0.2
- Malt heat capacity of about 0.4 against water's 1.0, scaled for a quart weighing about 2 lb.
- 0.41
- The same constant converted to the metric liter per kilogram ratio.
- allowance
- Extra degrees for a cold mash tun losing heat at dough in.
The physics is heat conservation: the hot water gives up exactly what the grain needs to rise from its temperature to the target. Beer and Brewing's dictionary describes strike water around 75 to 80 C for typical British ales, near the top of the range this tool produces for a 65 C target.
Worked example
Example: 10 lb into 1.25 qt/lb for a 152 F mash
Defaults: imperial, 10 lb grain, 1.25 qt/lb, grain at 65 F, target 152 F, no tun allowance.
- Ratio term: 0.2 / 1.25 = 0.16.
- Temperature gap: 152 - 65 = 87 F.
- Strike: 0.16 x 87 + 152 = 13.9 + 152 = 165.9 F.
- Volume: 10 x 1.25 = 12.5 qt = 3.13 gal.
- Metric mirror: 4.5 kg at 2.6 L/kg to 67 C gives 74.7 C and 11.7 L.
Reference table
| Ratio (qt/lb) | Strike temp (F) | Character |
|---|---|---|
| 1.0 | 169.4 | Thick mash, more body |
| 1.25 | 165.9 | Classic single infusion |
| 1.5 | 163.6 | Thinner, easier stirring |
| 2.0 | 160.7 | Sparse mash, less heat needed |
Limits
- Ignores heat lost to the tun while doughing in.
- Assumes typical malt heat capacity.
- Step mashes need their own infusions.
- Extreme ratios push the formula past practice.
Common mistakes
- Forgetting the tun allowance on a cold winter day.
- Doughing in without stirring; hot and cold pockets linger.
- Confusing strike temperature with mash target.
- Using a grain temperature from the fermenter, not the grain bin.
- Trusting one thermometer for both strike and mash.
Try it yourself
Quick checks. Answers sit tucked under each question.
5 lb at 2 qt/lb, grain 70 F, target 150 F?
0.1 x 80 + 150 = 158 F; add a couple of degrees if the tun is cold.
Why is a thicker mash hotter?
Less water shares the grain's heat load, so it must start hotter to land on target.
What if the strike temp exceeds 210 F?
The tool warns; use a thinner mash, more water, or a step infusion instead.
Questions
What is strike water?
The first water mixed with the grain at mash in, heated above the mash target so the mixture settles exactly on target.
Why 0.2 over the ratio?
Malt's heat capacity is roughly 0.4 of water's, and a quart of water weighs close to 2 pounds; the arithmetic collapses into 0.2 divided by quarts per pound.
What ratio should I use?
1.25 to 1.5 quarts per pound suits most single infusion mashes; thinner mashes favor conversion, thicker ones favor body.
Do I need a tun allowance?
If the tun is at room temperature or colder, yes: a few degrees in imperial, one or two in metric, covers the warm up loss.
Does grain crush or type change this?
Only slightly; the water to grain ratio and temperatures dominate. Roasted malts behave close to base malt for this balance.
How do I hit an exact mash pH?
Temperature lands the mash; pH is a separate water chemistry dial, usually managed with salts or acid.
Sources
- Brew Your Own, calculating water usage
- Brew Your Own, feel the mash heat
- Beer and Brewing strike water definition