Strike Water Temperature Calculator
Enter your grain temperature, grain bill and strike water volume, and your target mash temperature to get exactly how hot the water should be when it hits the grain.
Results
Value must be between 68 and 203.
How the formula works
Strike temperature = (0.41 ÷ ratio) × (mash target - grain temperature) + mash target, where ratio is liters per kilogram. Thicker mashes need hotter strike water because the grain carries most of the thermal mass. The 0.41 factor reflects the specific heat of malt relative to water.
After the mash, see what your grain bill actually delivered with the mash efficiency calculator, and log the resulting gravity - corrected for sample temperature if needed - with the hydrometer correction tool.
Frequently asked questions
Why does my mash land a few degrees below target?
The formula ignores the thermal mass of the mash tun. A cool stainless or cooler tun absorbs heat from the first water in, typically costing 2-5 F. Preheat the tun with hot water (or a short strike of near-boiling water), dump it, then dough in at the calculated temperature and you will land on target.
What water-to-grain ratio should I use?
Most homebrewers mash between 1.25 and 2.0 quarts per pound, which is about 2.6-4.2 liters per kilogram. Thicker mashes (around 1.25 qt/lb) favor fermentability and need hotter strike water; thinner mashes are easier to stir and hit temperature with cooler water. The calculator shows your ratio in both units.
Can strike water be too hot?
Yes. If the strike water goes above roughly 168 F (76 C) after dough-in, the beta-amylase enzymes that create fermentable sugars are denatured almost instantly, leaving a wort that ferments poorly and tastes thin. With very thick mashes, dough in a few degrees below the calculated value and stir before adjusting up.
Does grain temperature really matter?
More than most brewers expect. Grain stored in a 50 F garage versus a 70 F house shifts the strike temperature by several degrees for a typical ratio. Measure the grain itself - a cheap probe thermometer in the grain bucket is all it takes - and enter that number rather than guessing at room temperature.