Strike Water Temperature Calculator
This professional-grade calculator helps homebrewers and small craft brewers find the precise strike water temperature for single-infusion mashes. It solves the heat balance between water, grain, and (optionally) your mash tun to hit your target mash temperature with confidence.
Calculator
Switch units to match your equipment.
Results
Data Source and Methodology
Authoritative reference: John J. Palmer, “How to Brew,” 4th Edition, Chapter 16 (and online resources). See also Brewer’s Friend Mash resources at brewersfriend.com/mash. All calculations strictly follow standard heat-balance formulas documented by these sources. All calculations are strictly based on the formulas and data provided by this source.
The Formula Explained
General heat-balance with optional mash tun term:
$$ T_{strike} \;=\; T_{mash} \;+\; \frac{c_g\,m_g\,(T_{mash}-T_g) \;+\; c_t\,m_t\,(T_{mash}-T_{tun})}{c_w\,m_w} $$
When expressing heat capacities relative to water (i.e., using the ratio k = c_g/c_w ≈ 0.41 and tun mass as water-equivalent), this simplifies to:
$$ T_{strike} \;=\; T_{mash} \;+\; \frac{k\,m_g\,(T_{mash}-T_g) \;+\; m_{tun,eq}\,(T_{mash}-T_{tun})}{m_w} $$
If you ignore the mash tun (set its mass to 0), the well-known practical forms are:
$$ T_{strike} \;=\; T_{mash} \;+\; \frac{0.41}{R_{(L/kg)}}\,(T_{mash}-T_g) \quad\text{or}\quad T_{strike} \;=\; T_{mash} \;+\; \frac{0.20}{R_{(qt/lb)}}\,(T_{mash}-T_g) $$
Glossary of Variables
- T_strike: Strike water temperature to heat before dough-in.
- T_mash: Target mash temperature after mixing.
- T_g: Current grain temperature.
- T_tun: Mash tun temperature at dough-in.
- m_g: Grain mass.
- m_w: Strike water mass (≈ water volume in L or kg for metric; qt × 0.946 ≈ kg for US).
- R: Water-to-grain ratio (L/kg or qt/lb).
- k: Grain-to-water specific heat ratio (c_g/c_w), ≈ 0.41 (dimensionless).
- m_tun,eq: Mash tun water-equivalent thermal mass (L or qt).
- c_w, c_g, c_t: Specific heats of water, grain, and tun material, respectively.
Worked Example
How It Works: A Step-by-Step Example
Suppose you mash 10.0 lb of grain at 68 °F, aim for 152 °F mash temperature, and choose a 1.50 qt/lb ratio. Assume a preheated tun (set its thermal mass to 0).
- Water volume m_w = 10.0 × 1.50 = 15.0 qt.
- Using the US simplified form: T_strike = 152 + (0.20 / 1.50) × (152 − 68).
- Compute: (0.20 / 1.50) ≈ 0.1333; (152 − 68) = 84; 0.1333 × 84 ≈ 11.2.
- Therefore T_strike ≈ 152 + 11.2 = 163.2 °F. Heat water to ~163 °F and mash in promptly.
If your tun is at 60 °F with a 1.0 qt water-equivalent thermal mass, add the tun term from the general formula to increase T_strike by about: (1.0 × (152 − 60)) / 15.0 ≈ 6.13 °F, yielding approximately 169 °F.
Frequently Asked Questions (FAQ)
How precise should my strike temperature be?
Within ±1–2 °F (±0.5–1.0 °C) is typically sufficient. Stir well and check the mash; you can add a splash of hot or cold water for fine adjustments.
Should I preheat the mash tun?
Preheating improves consistency and reduces the tun term to nearly zero. If you skip preheating, include tun temperature and thermal mass for best accuracy.
Does crush size or mash thickness affect enzyme activity?
Yes. Finer crush and thinner mashes can increase conversion speed. Use this tool to hit your target temperature; recipe design will dictate your ratio and crush.
What if my grain temperature is very cold?
Colder grain requires hotter strike water. Take an accurate reading of grain temperature near dough-in time for better results.
Is BIAB (Brew in a Bag) different?
The heat-balance is the same. BIAB often uses thinner mashes (higher ratios), which slightly lowers the required strike temperature.
Why do some calculators give slightly different answers?
Different tools may use slightly different constants for grain heat capacity or omit tun effects. This calculator exposes the tun term explicitly.