Mash Calculators

Using the formulas from John Palmer's How to Brew, I have included some of the calculations I find useful for mashing.

The Water calculator determines the amount of water needed for the mash infusion in both quarts and gallons based on the amount of grains in the recipe and the ratio of water to grain that you are using.

The Strike Temperature calculator determines the initial temperature of water for your infusion based on desired final temperature of the mash, the initial temperature of the grains and the ratio of water to grain. This calculation is fairly accurate but I've found it to be a little low and typically add up to 5 ℉ to this result to determine my initial water temperature.

The Rest Water Amount calculator determines the amount of boiling water necessary to increase the mash temperature to the next rest for step mashes. Remember water boils at 212 ℉ at sea level and decreases approximately 1 ℉ for every 500 feet in elevation gain. I have set the default to 196 ℉ for the approximately 8,700 foot elevation I brew at. A word of caution when using this calculator. The majority of my brews have been single infusion mashes, but I didn't find this formula very accurate for the few stepped mashes I've completed. For single infusion mashes I will typically just incrementally add 0.5 gallons of boiling water to the mash if it has fallen below the target temperature when checking at 20 minute intervals.

The Decoction Amount calculator determines the volume of main mash necessary to increase the mash temperature to the next rest for decoction mashes. Remember water boils at 212 ℉ at sea level and decreases approximately 1 ℉ for every 500 feet in elevation gain. I have set the default to 196 ℉ for the approximately 8,700 foot elevation I brew at. A word of caution when using this calculator. It may be necessary to account for a decrease in temperature in the main mash while the decoction is being brought to a boil. The first time I attempted a decoction, I was about 8 ℉ lower than my target temperature using the volume calculated for the decoction.