Decoction Calculator

Decoction calculator for estimating volumes and temperatures on your decoction mash. Simply input your information where prompted, and numbers will automatically be calculated below.

Decoction Calculator Notes:

• Decoction Volume = (Total Mash Volume x (Target Temp – Start Temp ) ÷ (Boil Temp – Start Temp))
• Noticeable heat loss occurs between steps when using water cooler mash tun! 
  • Adjust 2-6 degrees up on new target temperature, use this calculator to adjust on the fly
• https://www.rackers.org/calcs.shtml has been taken into account when finding Total Mash Volume
  • Total Mash Volume in quarts = (Mash Weight x (0.078 + (Mash Thickness ÷ 4)) x 4
• If doing a Single or Double Decoction, enter same temperature as previous steps
• If doing longer 15 minute or longer decoctions and/or thinner (soupy liquidy) decoctions, modify decoction equation to include decoction boil off
  • Decoction volume = (Total Mash Volume x (Target Temp – Start Temp) ÷ (Boil Temp – Start Temp))+(Decoction Boil Time x Boil Rate)
• See below for rest temperature ranges

Mash Temps & Ranges