Mash Temperature Calculator

This calculator will find the strike water temperature and volume to hit the target temperature of a single mash infusion.

First fill in the calibration data and click the Calibrate button. The calibration data are constant for a given brew vessel and can be reused for all future mash calculations. Then fill in the desired mash data and click the Calculate button.

If you are interested in how this works, take a look at the Mash Physics page which describes the process and equations.


Measure the temperature inside the brewing vessel and the ambient temperature.
Prepare a carefully measured volume of hot water, measure its temperature (T0).
Add the hot water to the brewing vessel, put lid on, and take its temperature at 5 minutes (T5) and 65 minutes (T65).

Physical Constants
Water Specific Heat J/K/kg
Water density @60°F kg/L
Grist Specific Heat
(rel. water)
This quantity is unitless, a decimal fraction of the specific heat of water.

Calibration Data
Location Inside vessel Ambient (Room)  
Temperature °F °F  
Water volume @60°F US gallon    
Time: 0 minutes 5 minutes 65 minutes
Water Temperature °F  (T0) °F  (T5) °F  (T65)

Compute Strike Temperature

Input the mash batch data and click Calculate.

Mash Batch Data
Weight of grist
Grist Temperature °F
Ambient Temperature °F
Mash tun Temperature °F
Mash thickness
Target mash temperature °F
Mash time min
Vessel Calibration Constants
Vessel Heat Capacity J/K
Heat Loss Coefficient W/K

Strike water temperature °F
Strike water volume
Heat loss at target temperature W
Mash end temperature °F