Excellent. I have a mash tun
A couple of weeks ago I picked up a 25 litre esky that was on sale for $20 from the supermarket. I figured at that price, how could I pass up a DIY mash tun project?
A mash tun is the vessel in which a brewer mixes his grain with hot water to produce the liquid (called “wort”) that will eventually be converted into beer. This mix of grain and hot water is required to rest for designated periods of time at very particular temperatures. This “rest schedule” allows certain enzymes to become active and do their bit and convert starch into sugars. There are a number of different enzymes which need certain temperatures to become active. The “rest” is the period of time that they have to do their job within before the temperature changes and another group of enzymes become active and get cracking. The window of time that the the different enzymes have to do their work within will very much impact upon the final product’s body and character. Therefore, the rest schedule is an important tool that the brewer has to manipulate whatever particular beer they are brewing.
On the home front, the mash tun can be used for the same purpose but more so it is the item that enables a home brewer to start all grain brewing, and move away from the processed kit beers. It also introduces the same principles and concerns that professional brewers live with and therefore makes the entire brewing task a lot more stimulating and rewarding. Finally, it is possible to create a wort by letting the grain and water sit for an hour or so at one particular temperature, rather than doing the temperature controlled rest schedule. Therefore, the mash tun can be happily employed in the kitchen micro brewery to churn out a pretty incredible brew (naturally, contingent on plenty of other factors).
To convert my esky I bought a couple of other items such as steel braid (to use as a filter), a few plastic washers and a tap. I drilled a hole through one side and simply screwed everything in place. The end result is damn fine, took about 20 minutes to construct, and cost around $55. See pics below.
By the way, there are plenty of videos on you tube which demonstrate the construction process. Here is a great article on getting into all grain via a cooler and here is another on how to do a step mash infusion with a cooler.