Smile Politely

Building a Mash Tun

The first step taken toward advanced home brewing is the mashing process. Beginner kits skip the mash by providing the brewer with malt extract and a small amount of grain for steeping. This is infinitely more convenient, but brewers really can’t say they have experienced a true home brew until they have made the step to all-grain brewing.

The mashing process converts grain starches into sugars for fermentation. Sounds simple, but the mash is the primary place where taste, alcohol content and appearance are determined. The most popular form among home brewers is called infusion mashing, which involves placing crushed grains and hot water in a sealed cooler for around an hour. The cooler provides constant temperature for the grains; which is important for activating the correct enzymes involved in converting starch into sugars.

A home brewer’s mash tun is usually a converted ten-gallon Rubbermaid cooler (the kind you serve Gatorade in at football games) or in some cases a rectangular food cooler. I use the rectangular version since it was cheaper at Wal-Mart, but the Rubbermaid is a better choice (if you have the money) because it creates a deeper grain bed, increasing efficiency.

Mash Tun Build:

1) Place a false bottom in the cooler with a hose attached for draining wort. If you can’t find a false bottom, a mesh hose coiled at the bottom of the cooler works well for separating grains from wort.

2) Replace the original spigot included with your cooler with sealed tubing, or a metal pipe and faucet.

3) Pour two gallons of hot water (~170 deg F) into the mash tun and check for leaks. In the case of a small leak, it helps to add rubber O-rings on either side of the cooler’s walls. A large leak may require a new approach to your draining apparatus.

This is the simplest way of mashing, but if you are ambitious then try converting an old keg into a pot big enough to maintain a constant temperature over a propane-fed turkey burner. Missing the return deadline at Piccadilly might turn into a great opportunity!

Hop Politely will feature brewing video in the next installment.

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