Brew tools

Strike Water Calculator: Strike Temperature, Mash and Sparge Water

How hot your strike water should be and how much water you need for the mash and the sparge, for a mash tun or a full-volume all-in-one system.

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How to use it

  • Pick your method. Mash then sparge for a mash tun or HERMS; full volume for all-in-one systems and brew-in-a-bag, where all the water goes in at the start.
  • Enter the batch, grain and temperatures. For 11 lb of grain at 68°F and a 152°F mash at 1.5 qt/lb, the strike water goes in at about 163°F.
  • Set your equipment once. Boil-off, grain absorption, dead space and kettle loss decide how much water you need in total. Measure your boil-off once and the numbers get much closer.

The strike water formula

The standard infusion equation from John Palmer’s How to Brew:

Strike temperature = (0.2 ÷ r) × (mash temperature − grain temperature) + mash temperature

Here r is the mash thickness in quarts per pound and the temperatures are in °F. In metric, use 0.41 instead of 0.2 with r in litres per kilogram and temperatures in °C. A thicker mash needs hotter water; a full-volume mash, at about 2.75 qt/lb, needs only a few degrees above the mash temperature (about 158°F for a 152°F mash).

Strike temperature chart

Mash thickness148°F (64°C)150°F (66°C)152°F (67°C)154°F (68°C)156°F (69°C)158°F (70°C)
1.25 qt/lb (2.6 L/kg)161°F (72°C)163°F (73°C)165°F (74°C)168°F (75°C)170°F (77°C)172°F (78°C)
1.5 qt/lb (3.1 L/kg)159°F (70°C)161°F (72°C)163°F (73°C)165°F (74°C)168°F (75°C)170°F (77°C)
1.75 qt/lb (3.7 L/kg)157°F (70°C)159°F (71°C)162°F (72°C)164°F (73°C)166°F (74°C)168°F (76°C)
2 qt/lb (4.2 L/kg)156°F (69°C)158°F (70°C)160°F (71°C)163°F (73°C)165°F (74°C)167°F (75°C)
2.75 qt/lb (5.7 L/kg), full volume154°F (68°C)156°F (69°C)158°F (70°C)160°F (71°C)162°F (72°C)165°F (74°C)

Strike water temperature for grain at 68°F (20°C) and a preheated mash vessel, by target mash temperature. Colder grain: add about 1.3°F per 10°F colder at 1.5 qt/lb.

How much water for 5, 10 and 20 gallons?

BatchGrainMash and sparge: mash + sparge waterFull volume: total water
5 gal (19 L)11 lb (5 kg)4.1 gal (16 L) + 4.2 gal (16 L)7.6 gal (29 L)
10 gal (38 L)22 lb (10 kg)8.2 gal (31 L) + 7.3 gal (28 L)14.2 gal (54 L)
20 gal (76 L)44 lb (20 kg)16.5 gal (62 L) + 12.9 gal (49 L)26.9 gal (102 L)

For a beer of about 1.050 with a 60 minute boil. Assumes boil-off of 1, 1.25 and 1.5 gal/hr; kettle loss of 0.5, 0.75 and 1 gal; dead space of 0.25, 0.5 and 0.75 gal; absorption 0.12 gal/lb (0.08 full volume with a drained basket); 1.5 qt/lb. Your numbers will differ: use the calculator.

Questions

How hot should strike water be?

With grain at room temperature, about 8–14°F above your target mash temperature for a mash tun at 1.25–2 qt/lb, and about 6°F above it for a full-volume mash. For 11 lb of grain at 68°F mashed at 152°F and 1.5 qt/lb, it is about 163°F.

How much strike water do I need?

Multiply the grain weight by the mash thickness. At 1.5 qt/lb, 11 lb of grain takes 16.5 quarts (4.1 gallons). For a full-volume mash, the strike water is all the water for the brew day.

How hot should sparge water be?

About 168–170°F (76–77°C). That keeps the grain bed near 168°F, where the wort runs freely and the enzymes stop. Much hotter than 170°F in the grain bed can pull tannins from the husks.

How much water for a 5 gallon all-grain batch?

Typically 7.5 to 8.5 gallons in total. Grain absorption, boil-off and what stays in the kettle all add to the 5 gallons that reach the fermenter. The calculator shows where every quart goes.

Why did my mash come in too cold?

Usually a cold mash vessel. The formula assumes it is preheated; a stainless tun or cooler at room temperature absorbs a few degrees. Preheat it with hot water, or add 2–3°F (1–2°C) to the strike temperature. Stirring well and checking after 5 minutes helps too.

Full volume or sparge?

Full volume is simpler: one vessel, all the water at the start, no sparge. A mash and sparge usually gets a few points more efficiency and leaves more room in the mash vessel. All-in-one systems like the Unibräu usually run full volume; a HERMS mashes and sparges.