Mash & Sparge Water Volumes
Total brewing water, strike and sparge volumes worked back from the fermenter: boil-off, kettle losses, grain absorption and dead space are yours.
Total water for the brew day, strike water for your mash thickness, sparge water, the pre-boil volume, and a line-by-line budget of every loss — in gallons and pounds or litres and kilograms.
Example: 5.5 gal into the fermenter from 11 lb of grain at 1.25 qt/lb: 8.82 gal of water in all, 3.44 gal to mash and 5.38 gal to sparge.
Work back from
the fermenter.
How the volume budget is built from the fermenter back to the mash tun, and which losses are yours to measure.
Pre-boil volume
Start from what should reach the fermenter, add what stays in the kettle (trub, hops, the chiller) and what the boil drives off — your kettle’s boil-off rate times the boil time. That is the volume to collect before the boil.
Total water
Add the water the grain keeps after draining and the dead space under the mash tun’s false bottom or outlet. Absorption depends on the grain and how hard it is drained, so measure your own: total water in, minus wort out, divided by the grain weight.
Strike and sparge
Strike water is the grain weight times the mash thickness (quarts per pound, shown in gallons, or litres per kilogram); sparge water is the rest. If the mash water alone covers the total, the page says so — that is a no-sparge or brew-in-a-bag brew.
What the numbers do not settle
Wort shrinks as it cools, and hops soak up wort; measure both once and fold them into the kettle loss. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.