Skip to content

Mash Temperature & Strike Water Calculator

All-grain brew day tool

Mash temperature and strike water calculator

Estimate the strike water temperature you need to hit your mash rest. Enter your grain weight, grain temperature, mash thickness or water volume, and target rest temperature.

Common single-infusion rests are 148-158 deg F.
Use the actual room or storage temperature of the grain.
1.25-1.50 qt/lb is a common starting point.
For BIAB or no-sparge, use the water volume you plan to mash with.
Add a few degrees if your tun is cold or unheated.
Preset choices only adjust the target temperature.

How the strike water calculation works

This calculator uses the standard homebrewing strike-temperature equation: strike temp equals target mash temp plus the grain heat correction. In U.S. units, the correction is (0.2 / mash thickness) x (target temp - grain temp). The optional equipment offset lets you account for heat lost to a cold mash tun, kettle, or transfer.

Use the result as a starting point. Real systems lose heat differently, so note your actual mash-in result and adjust the offset on the next batch.

What mash temperature changes in beer

Mash temperature affects how fermentable the wort is. A lower single-infusion rest, often around 148-150 deg F, tends to make a drier beer. A middle rest around 151-153 deg F is a useful target for many pale ales, lagers, wheat beers, and balanced amber beers. A warmer rest around 154-158 deg F can leave more body and sweetness.

The strike water temperature is always higher than the target mash temperature because the grain absorbs heat when you mix it in. Cold grain, a thick mash, and a cold mash tun all push the required strike temperature higher.

How to use this on brew day

  1. Weigh the full grain bill, including specialty malts and flaked grains.
  2. Measure grain temperature before heating water.
  3. Choose either mash thickness in qt/lb or the mash water volume you plan to use.
  4. Heat strike water to the calculated temperature, mix thoroughly, and check the mash after the grain is fully wetted.

If your system misses high or low in a repeatable way, use the equipment offset field. A cooler, unheated mash tun may need a positive offset. A preheated kettle or insulated system may need little or none.

Related brewing tools

After brew day, use the ABV calculator to estimate finished alcohol, the priming sugar calculator before bottling, and the keg carbonation calculator when serving from a draft system.