🌡️ Strike Water Calculator
Enter your grain weight, its temperature, your target mash rest, and water-to-grain ratio to get the exact strike water temperature and volume — so you nail your mash on the first pour.
🌡️ Calculate Strike Water
What is a Strike Water Calculator?
It works out how hot to heat your mash water so that, once it hits the cool grain, the whole mash settles at your target rest temperature. Mash a few degrees off and you shift the balance between fermentable and unfermentable sugars — which changes the body and dryness of the finished beer.
Enter your grain weight and temperature, the mash rest you're aiming for, and your water-to-grain ratio, and the calculator returns both the strike temperature and the volume of water to mash in with. It takes the trial-and-error out of doughing in, especially for all-grain brewers dialling in a new recipe.
❓ Frequently Asked Questions
How does the strike water calculator work?
It uses the standard infusion formula: strike temp = (0.41 ÷ ratio) × (target − grain temp) + target, where the ratio is litres of water per kilogram of grain. Because cool grain absorbs heat on contact, the water must start hotter than your mash target. It also multiplies grain weight by the ratio to give your total mash water volume.
Why does strike water need to be hotter than my mash temperature?
When hot water hits room-temperature grain, heat flows into the grain until both settle at an equilibrium — the mash temperature. To land on your target rest, the water has to start several degrees higher so that, once the grain has soaked up its share of heat, the mixture stabilizes exactly where you want it.
What water-to-grain ratio should I use?
A thickness of around 2.5–3.5 litres per kilogram (roughly 1.2–1.7 quarts per pound) suits most single-infusion mashes; 3 L/kg is a common default. Thinner mashes are more temperature-stable and easier to convert, while thicker mashes favour some enzyme activity — but the sweet spot is mostly about your equipment and sparge method.
Should I preheat my mash tun?
Yes — a cold mash tun steals heat and can drop you below target, especially in a cooler-style tun. Rinse it with hot water first, or add a degree or two to the calculated strike temperature to compensate. After a few brews on your own kit you'll know its exact heat loss and can fine-tune.