Mash Temperature Calculator

Enter your grain weight, mash water ratio, target mash temperature, and grain temperature to calculate the exact strike water temperature needed for your all-grain brew. The Mash Temperature Calculator uses the classic infusion formula to tell you how hot your strike water needs to be so the mash hits your desired rest temperature — no guesswork, no thermometer surprises.

Total weight of all grains in your mash

Quarts per pound (US) or liters per kg (Metric). Typical range: 1.0–1.5 qt/lb

Desired temperature of the mash after strike water is added (°F or °C)

Current temperature of your grains (room temp or milled temp)

212°F at sea level; lower at altitude (e.g. 208°F at 5000 ft)

Results

Strike Water Temperature

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Mash Water Volume

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Thermal Mass Ratio

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Temperature Unit

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Temperature Profile: Grain vs Target Mash vs Strike Water

Frequently Asked Questions

What is strike water temperature?

Strike water temperature is the temperature your mash water needs to be before you add it to your grain. Because the cold grain absorbs heat from the water, you need to heat the water slightly above your target mash temperature. The exact amount depends on your water-to-grain ratio and the grain's starting temperature.

What is a good water-to-grain ratio for mashing?

Most all-grain brewers use a ratio between 1.0 and 1.5 quarts per pound (or 2.1–3.1 liters per kg). A thicker mash (lower ratio) favors body and mouthfeel, while a thinner mash (higher ratio) can improve efficiency and fermentability. A ratio of 1.25 qt/lb is a popular middle-ground starting point.

What temperature should I mash at for a typical ale?

Most ales are mashed between 148°F and 158°F (64–70°C). Mashing at the lower end (148–152°F) produces a more fermentable wort with a drier, lighter body. Mashing at the higher end (154–158°F) leaves more unfermentable dextrins for a fuller-bodied, sweeter beer.

Why does altitude affect the boiling temperature of water?

At higher altitudes, atmospheric pressure is lower, which means water boils at a temperature below 212°F (100°C). For example, at 5,000 feet above sea level, water boils around 202–203°F. This slightly affects infusion calculations, which is why the boiling point is an adjustable input in this calculator.

How is the strike water temperature formula calculated?

The classic formula is: Strike Temp = (0.2 / ratio) × (target_mash_temp − grain_temp) + target_mash_temp. The constant 0.2 represents the approximate specific heat of grain relative to water. This formula is widely used in homebrewing and provides reliable results for single-infusion mashes.

What happens if my mash temperature is too high or too low?

If your mash goes above about 168°F (76°C), you risk denaturing amylase enzymes, stopping conversion and leaving unfermentable starches. If it's too low (below ~145°F / 63°C), conversion may be slow or incomplete. Aim to stay within a few degrees of your target for consistent results.

Do I need to account for heat loss in the mash tun?

Yes — in practice, your mash tun will absorb some heat, especially if it's cold or thin-walled. Preheating your tun with hot water before mashing helps minimize this effect. Some brewers add 1–3°F to their calculated strike temperature as a buffer for heat loss to equipment.

Can I use this calculator for step mashing?

This calculator covers the initial strike water (first infusion). For step mashing, you would add boiling or near-boiling water infusions at subsequent rest steps to raise the mash temperature. The volume and temperature of each infusion can be calculated using the same underlying formula applied to the new target rest temperature.

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