Construction of a Mash and Lauter Tun

I have only been brewing beer for a few months, but i'm ready to jump into All-Grain brewing. I was afraid to make the jump mainly because I thought it would be a large investment. I did some research and realized there was nothing to be afraid of, I already had the perfect cooler to convert to the Mash and Lauter Tun, so I only needed around 30 dollars worth of material to make the conversion. I would also need to find a larger brewpot and a burner that could bring 6+ gallons to a boil easily... luckily Walmart had a good deal on a Outdoor Lobster Boil kit.

Coleman Extreme cooler which I received as a gift years ago. I never really used it because its odd shape inside made it difficult to fill properly with beer.

Outdoor Lobster boil kit which will be my new brewpot.

Why do I need a Mash / Lauter Tun? - Up until this point I have been brewing partial mashes which rely on a malt extract, which is a product produced strictly for home brewers. Basically someone has already mashed the grains for you and sells it in a concentrated syrup. Partial Mash brews rely on the extract for over 90% of the fermentable sugars and then during my brew a small amount of grains are steeped to add color and mouth feel. The Mash and Lauter Tun will allow me to brew an All-Grain Beer without using any extracts. This will produce a much higher quality beer and will allow me more freedom with the recipes. It will also eliminate any "homebrew twang" off taste that may have been present as a result of the manufactured extract syrups. To be able to Mash I need a vessel which is large enough to hold over 10lbs of grain with water at a steady temperature for about an hour..... a cooler is perfect for the home brewer. Mashing allows the enzymes in the Malt to break down the starch in the grain to sugar. Lautering is the process of separating the liquid wort from the grains. I have built a manifold in the bottom of the cooler that will allow me to do just that ..... hence the Mash and Lauter Tun will be a single vessel.

Why do I need a larger Brewpot? - Previously I was boiling half the batch and topping up the fermenter with cold water to get the full batch size. I was able to do this because I was using a concentrated extract. When Mashing, I will have to be sure to use the proper amount of water and will be boiling a full 5 gallon batch. 

Before I get too far, most of the info for this conversion came from Home Brew Talk Forums and specifically http://www.homebrewtalk.com/wiki/index.php/Converting_a_cooler_to_a_mash_tun

The first step was to remove the spigot from the cooler and construct a water tight passage that would have a ball valve on the outside to control flow speed and a coupler on the inside that would be able to receive the manifold. I used a 1" diameter, 2" long brass pipe nipple, on the inside I reused the rubber gasket from the original spigot and threaded on a 1" coupler. On the outside I threaded on the ball valve and used washers to space it and keep it snug.

1" coupler threaded to the pipe nipple - here you can see the re-used rubber gasket from the original spigot

ball valve on the exterior spaced with 4 washers.

Next I built the manifold. I cut the copper pipe to the lengths I required and simply pieced it together using tees and 90 degree bends. Everything fits snug together so no welding was required which will make this easy to disassemble for cleaning and maintenance. I used two 45's to line up with the exit to the valve as instructed in the homebrew wiki link above, however the manifold would not sit flat on the bottom. I simply offset it slightly to allow the manifold to sit flat on the bottom. A series of slits were cut into the bottom of the manifold which when completed will allow the wort to drain from the cooler and leave the grains behind. There was really no science to the pattern of the manifold or the spacing of the slits, I just hope it does what I need it to do.

The copper manifold constructed and in place

The bottom of the manifold reveals the slits

closer view

I then heated up some water to 160F using the new brew pot to test the MLT for leaks and everything was perfect, not a drop.

I now am excited to choose a simple recipe for my first All-Grain brew day, and find some time to do it. When I was brewing extracts and only doing half boils, I was able to cool the hot wort by topping it up with cold water. now that I will be doing a full boil, I will need a method to cool the wort quickly to an appropriate temperature for pitching the yeast. Until I have the time to build a wort chiller, I will have to use a large bucket of ice water.

Thanks for reading - All Grain Brew Day post hopefully coming soon.