Mashing in is the process that extracts all the fermentable sugars from the malt. It's one of the most important steps for all-grain brewing and here's how to do it.  

Mashing in is the process that extracts all the fermentable sugars from the malt. 

Beer is brewed by fermenting the sugars of malted barley and other cereal grains. The malted grain has to be crushed, the form that most homebrewers buy it in, although some will crush it themselves. This crushed malt is then soaked in hot water in a process known as ‘mashing’. Mashing activates the enzymes, which convert the grain’s starch into sugars. These sugars are then rinsed from the grain, and the resulting liquid, known as ‘wort’, is boiled with hops and other ingredients. After boiling and cooling the hopped wort, yeast is added to kickstart fermentation and eventually produce beer. 

1/ Transfer water to mash tun. Using a jug, transfer your water, heated to strike temperature, to the mash tun.

2/ Add grist. Slowly pour in your malts (no need to keep different malts separated) stirring all the time with a long spoon. There can’t be any clumps of malt, instead it should be a smooth porridge-like mixture.

3/ Take temperature. The temperature should stabilise at 67ºC. Be aware that there can be cool spots in the mash so test it in a couple of areas. If it’s not hot enough heat some water in a regular kettle and stir in well. If it’s too hot add a little cold water. It must not go over 75ºC.

4/ Rest for an hour. During this saccharification rest, malt enzymes convert the grain’s starch into fermentable sugars.

5/ Heat sparge water. While the mash is resting, heat 2.5 litres for every kilogram of dry malt to 76ºC.



A multiple-step infusion mash is different from a singe-step infusion mash because it includes a protein rest of 20-30 minutes at different temperatures. This is particularly used in lager and Belgian brewing. A protein rest reduces haze, improves body and head retention and creates a nutrient-rich wort for yeast.