Basics and units
Strike water temperature
Cold grain steals degrees from the water. Heat it just enough: the tool gives the water temperature before you add the malt.
Result
Fill in the values and run the calculation, or try the example.
This is the calculation Krausi uses. Create an account to save it in a recipe or a brew.
Create my accountWhy calculate the strike water temperature?
The mash temperature decides the body of the beer. At around 63 °C, the enzymes produce very fermentable sugars: the beer will be dry. At around 68 °C, they leave longer sugars: the beer will be full. Missing the step by a degree or two therefore changes the result.
But the malt is at room temperature. Poured into the water, it cools it by several degrees. You have to heat the water above the target temperature, neither too much nor too little.
It is the first move of brew day: better to calculate it the day before than to fumble in front of the mash tun.
How is the water temperature calculated?
The tool does the heat balance between the water and the grain:
T water = 0.41 × grain / water × (T target − T grain) + T targetwith the grain in kg, the water in litres and the temperatures in °C. The coefficient 0.41 is the heat capacity of malt relative to that of water.
The colder the grain, the hotter the water must be: with malt stored at 10 °C in a garage, allow 73.6 °C instead of 72.3 °C. Add 1 to 2 °C if your tun is cold and not preheated.
Worked example
Values entered
- Grain weight in kg: 5
- Volume of mash water in litres: 15
- Target mash temperature in °C: 66
- Grain temperature in °C: 20
Result from the tool
- Strike water temperature in °C
- 72.29 °C
What the tool does not do
- The heat absorbed by the tun is not counted: preheat it with hot water, or add 1 to 2 °C.
- The tool reports an error if the water would have to exceed 100 °C: you then need more water.
- Losses during transfer are not taken into account.
Frequently asked questions
Why is my mash always too cold?
Most often, the tun is absorbing heat, or the malt was colder than expected. Preheat the tun with a little hot water and enter the true grain temperature. If you are still a degree or two short, the correction by adding hot water rescues the step.
What mash temperature for a dry or a full beer?
Between 62 and 65 °C for a dry, well-attenuated beer, between 67 and 69 °C for a full, sweeter beer. 66 °C is a common compromise.
And with the assistant?
Ask Krausi the same question in plain language: he picks this tool, does the calculation and files the result in your project.
Tomorrow I'm brewing with 5 kg of malt and 15 L of water, aiming for 66 °C. What do I heat the water to?
Heat the water to 72.3 °C if your malt is at 20 °C. If your tun is not preheated, go up to 73 or 74 °C. I'm adding it to the notes of tomorrow's brew.