Mash Calculator

Getting Started

How does the Mash Calculator tab work?

The Mash Calculator tab helps track the mash as it happens in terms of volume and temperature. The first step is to add the strike water and start the mash - please see the Strike Water for more on that. Batch Sparging - basic procedure for a 2 step sparge:

  1. Add Strike Water

  2. Use the Infuse or Add Boiling tab to hit rest steps, or to adjust as needed

  3. Drain to Kettle (1st runnings)

  4. Batch Sparge Tab - infuse remaining mash water

  5. Drain to Kettle (2nd runnings)

The system will only count grain absorption and mash tun dead space on the first 'drain to kettle' step! Fly Sparging:

  1. Add Strike Water

  2. Use the Infuse or Add Boiling tab to hit rest steps, or to adjust as needed

  3. Fly sparge - automatically accounts for grain absorption and mash tun dead space, and allocates the remaining volume to the kettle.

For RIMS / HERMS brew rigs:

  1. Add Strike Water

  2. Raise Temp / Record Temp for any rests

  3. Batch sparge then drain to kettle, or fly sparge


  1. Add Strike Water

  2. That's it since you are mashing with enough water to hit your pre-boil volume after pulling out the grain bag.

Temperatures are Estimates: Keep some cool and boiling water on hand to make small adjustments as necessary. Record any cool or boiling water added to the mash using the Infuse / Add Boiling tabs. You may also add comments to the mash log under the comments tab on the left. Brewing In A Cold Area: The equations powering this feature are geared for room temp (68 °F / 20 °C). If you are brewing in a cold area, compensate accordingly. For example, if the ambient temperature is 45 °F / 7 °C, we recommend padding by up to +10 °F / +5.5 °C. Better to overshoot a few degrees and leave the lid open vs having to add boiling water to heat it up. Additional Information: The water volume estimate comes from the Water Requirements tab, and uses settings from your equipment profile to compute how much water will be needed. If you change your profile options, go the Brew Session -> Edit tab, and click Rebuild to regenerate the water requirements table. Mash steps from the recipe are provided at the bottom of the Mash Calculator tab for reference. The data from the mash steps does not factor into the calculations, except as defaults where the system can pick them up.

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