Strike Water Temperature Calculator

About this calculator

All-grain brewers heat "strike water" hotter than the target mash temperature because mixing it with room-temperature grain pulls the combined temperature down. The standard homebrewing formula is: strike temp = (0.2 ÷ R) × (target mash temp − grain temp) + target mash temp, where R is the water-to-grain ratio in quarts per pound (or the metric equivalent) — the 0.2 constant reflects the specific heat ratio between water and grain.

Homebrewers use this every brew day to hit their mash temperature on the first try instead of scrambling to add boiling or ice water mid-mash, and professional brewmasters rely on the same relationship when scaling recipes to different mash tun sizes and grain bills, since hitting the right mash temp directly controls the fermentability and body of the finished beer.