Mashing
In the mash, enzymes turn the starch in the malt into sugar. The temperatures you choose decide whether your beer turns out lean and dry or full-bodied.
What you need
- Crushed malt
- Mash water – the water volume calculator tells you how much
- A kettle or brewing system with a thermometer
- A spoon or mash paddle
- Iodine solution and a white plate
- A pH meter or pH strips (recommended)
Step by step
Step 1Heat the mash water
Heat the mash water to the strike temperature. It is a few degrees above the first rest because the cold malt lowers the temperature. The water volume calculator tells you the exact temperature.
Step 2Stir in the malt
Add the crushed malt slowly and stir well so no lumps form. Then measure the temperature in several places and adjust with a little hot or cold water if needed.
Step 3Hold the beta rest
Keep the mash at 62 to 64 °C (147 °F) for 30 to 45 minutes. In this range beta-amylase is active and makes highly fermentable sugar. The longer this rest, the drier the beer.
Step 4Saccharification rest
Then heat to 70 to 72 °C (162 °F) and hold for 20 to 30 minutes. Alpha-amylase now breaks down the remaining starch. A longer rest here gives more body.
Step 5Do the iodine test
Put a drop of mash liquid without grain on a white plate and add a drop of iodine. If it no longer turns blue-black, the starch has been converted. Otherwise extend the rest by 10 minutes and test again.
Step 6Check the mash pH
Measure the pH of a cooled sample 10 to 15 minutes after mashing in. Ideal is 5.2 to 5.6. If it is higher, a little lactic acid helps.
Step 7Mash out
Finally heat to 76 to 78 °C (172 °F). This stops the enzymes and makes the wort thinner so it runs off better when lautering. Don’t go above 78 °C (172 °F).
Tips and common mistakes
- A single rest at 65 to 67 °C (153 °F) works for many beers and is the easiest way to start.
- Stir constantly while heating so nothing scorches on the bottom of the kettle.
- For dry beers such as Pils or saison rest longer at 62 to 64 °C (147 °F), for full-bodied beers such as Märzen or stout longer at 70 to 72 °C (162 °F).
- Measure the temperature in the middle of the mash, not at the edge of the kettle, where it is often warmer.
Matching calculators
New to brewing? The “First beer” guide walks you through your first brew day. Your first beer