Whirlpool Temperature & Dilution Calculator

Brew Day Mode:

Use this when you're at the end of your boil and want to know how much cold water to add to reach your target whirlpool temperature.

1. Enter your current wort volume and gravity
2. Enter your wort temperature (usually boiling)
3. Enter your cold water temperature
4. Enter your target whirlpool temperature (typically 170-190°F / 77-88°C for hop stands)
5. The calculator shows how much water to add and your final gravity after dilution

Planning Mode:

Use this before brew day to plan your recipe. This tells you what gravity and volume to collect so that adding cold water will hit both your target OG and whirlpool temperature.

1. Enter your target final volume (into the fermenter)
2. Enter your target gravity (OG)
3. Enter your expected wort and water temperatures
4. Enter your target whirlpool temperature
5. The calculator tells you what gravity and volume to collect, and how much water to add

Tips:

• Common whirlpool temperatures: 170-185°F (77-85°C) for hop stands
• This calculator assumes water and wort have similar specific heat capacities (close enough for practical brewing)
• Account for some temperature loss when transferring to your fermenter
• In planning mode, you may need to boil longer or use DME to hit the higher pre-dilution gravity
• Always measure your actual volumes and temperatures on brew day for best results