Ask Mr. Wizard

What’s the best way to check the temperature of a mash?


Gilbert Korrubel • The Hague, Netherlands asks,

What’s the best way to check the temperature of a mash? I use a five-gallon, round picnic cooler (Rubbermaid). The first time I did an all-grain brew, I followed “The New Complete Joy Of Homebrewing” by Charles Papazian (Avon Books, 1991). It says to raise the temperature of the water about 12° to 17° F above the desired mash temperature. I did this and the mash temperature dropped to 144° F; I was targeting a temperature of 152° F. I checked it with a dial thermometer. I also used 170° F sparge water. What is the temperature drop of sparge water?

The best way to check mash temperature is with a calibrated-dial or alcohol-filled thermometer. The easiest way to calibrate a thermometer is by filling a glass with ice cubes and then filling the glass with water. In
Response by Ashton Lewis.