The decision to begin all grain brewing is exciting for many brewers, but the cost of the equipment can be prohibitive. Before you plunk down $200 for a hot liquor tank and a mash/lauter tun, learn how easily you can build your own for a fraction of the cost.

The instructions available online are all very similar, but there are a few notable differences; the size and shape of the coolers, and the method of collecting the wort. Round coolers will offer greater grain bed depths but tend to be limited by volume. Rectangular coolers offer great volume, but may suffer from shallow grain bed depths. Both shapes of coolers work well, so this becomes a choice based more on personal preference.

Replicating the function of the false bottom in the lauter tun is a little trickier. Some people use the stainless steel braid from a supply hose to filter and channel the wort out of the tun. Others make a grid out of copper tubing and drill holes or cut slots to allow wart in while keeping the grain out. While many people are satisfied with the results these two methods offer, the HomeBrew Garage recommends that you purchase a stainless steel false bottom for your homemade lauter tun.

We recommend the stainless steel false bottom for a few reasons. Since there is no ‘interrior’, the false bottom is easy to clean and sanitize. Wort should also filter more evenly thru the grain bed since it collects and is drawn from the cavity under the false bottom. Lastly, for the $28 dollar cost of the false bottom, we don’t think it is worth the cutting, fitting, and soldering of the copper tubing solution. We do acknowledge that all methods work and many homebrewers are perfectly satisfied with their braded hose or copper pipe filters.

With the above in mind, here is how we assembled our homemade mash and lauter tun. We chose to begin with two 5 gallon round coolers; one to act as the hot liquor tank, the other as the mash and lauter tun. The stainless steel false bottom and high temperature tubing were ordered online and the rest of the plumbing fittings came from the local hardware store.

A parts list is included below under 'costs', but you can see what you need from the photo to the right. You may need to change this slightly based on parts availability, the size of your tubing, etc. A word of caution: make sure the metal fittings you buy are stainless steel, brass, or bronze and that rubber-washers, o-rings, and any fasteners are food safe. 

Assembling your Homemade Mash - Lauter Tun

Begin by removing the push button tap from the cooler by unscrewing the nut inside the cooler. The tap should push right out and you can remove the gasket from the hole. Depending on the opening of the gasket and the size of the plumbing fittings you buy, you may be able to reuse this. Reusing the gasket will save you time and frustration spent hunting for o-rings and rubber washers to make your coolers watertight.

If you are not using the original gasket, insert an o-ring into the hole and arrange between the inner and outer cooler walls. Slide the threaded nipple thru the hole in the cooler (and the o-ring), and slip the rubber washer or o-rings on first so that they contact the side walls of the cooler.

You will need to experiment to determine the number of washers necessary. The fewer you use the better, but you need enough that you can compress the sides of the cooler enough to form a good seal when you screw on the final internal and external fittings.

Wrap the nipple threads with Teflon tape to ensure a water tight fit and screw the barbed nipple inside the cooler and the ball valve on the outside.  Make sure the handle will operate freely (if it is on backward, you won’t be able to open the valve since the handle will hit the cooler wall). Apply Teflon tape to the male-threaded barbed nipple and screw it into the ball valve. 

Repeat the above steps on the second cooler. Dry fit the false bottom into the cooler to determine the length of high-temp tubing necessary to complete assembly. Attach the tubing to the barbed nipples with stainless steel clamps or zip ties and you are in business.

Congratulations, your all grain brewing equipment is ready for service. A sweet HomeBrew Garage logo optional, but highly recommended. 

Homemade Mash - Lauter Tun Costs

Buying the false bottom raised the overall cost of the project, but we feel like our homemade mash / lauter tun is every bit as good as the ready made kit. Here is a summary of costs for the project.

Final Thoughts

We didn’t take pictures during the original assembly, so we dissembled one of the coolers to take a few pictures. The good news is that not only can we can report how our setup has been working, but also what we would change if we had to do it again. 

The ‘bigger is better’ mentality got us again; if we had purchased smaller fittings, we would have been able to use the gasket that came with the cooler. This would have simplified installation and the parts would have been slightly cheaper. Since our fittings were so large, the washers were huge and wouldn’t lay flat on the interior of the cooler. We finally found smaller washers for the inside of the cooler so that we could get a watertight seal.

To date, we have used this setup for 8 batches with no leaks detected. We have been very satisfied with it's performance and are glad we saved some money by building this ourselves.