How to make a mash/lauter tun out of a GOTT cooler

What I use is a standard 10 gal Gott drink cooler. As opposed to other brands, the Gott is specifically made for hot and cold beverages and therefore stands up well to mashing temps.

The procedures are very simple.

  1. Remove the valve assembly
  2. Buy a Phil's Phalse Bottom (the 10 gal size for about $25)
  3. Add a bulkhead fitting to the cooler in place of the valve
  4. Connect the false bottom to the bulkhead fitting

You can figure out how to remove the valve and buy the false bottom yourself. If not, don't try this at home. Hire a professional. B-}

Bulkhead Fitting

A bulkhead fitting is a way of getting an attachment for plumbing on two sides of a plate (bulkhead). The simplest bulkhead fitting is made with a close nipple, two rubber washers, two stainless steel washers and two pipe thread nuts. Place the nipple through a hole in the plate. Slip over a rubber washer, a SS washer and then run on the nut. From the other side, do the same. Tighten the two nuts against each other to form a seal. If the bulkhead is curved like in a round cooler, you may need very soft rubber gaskets, but if it is flat, the rubber can be harder. O-rings sometimes work. If you cannot get pipe nuts, you can make them by buying reducer fittings. For a 1/2" pipe nut, buy a 3/4" to 1/2" reducer. Hold the 3/4" threaded portion in a vise and use a hacksaw to cut off the hex nut portion. These are available for sale from McMaster-Carr in brass or bronze, but I have only seen them in retail stores in pot metal which one would *not* want to use in brewing. For use with a false bottom, *USE* the reducer, not the pipe nut and *DO NOT* cut off the threaded portion. This will be used as an adapter for the hose from the false bottom. A 1/2" ballvalve on the outside of the bulkhead fitting can be used in place of the pipe nut, and you probably want a valve anyway.

Phalse Bottom Mods

A Phil's Phalse Bottom is a circle of 1/8" plastic, slightly domed and with gazillions of small holes in it. In the center is one 1/4" NPT threaded hole into which a plastic elbow has been screwed. The other end of the elbow is about a 1/4" hose barb. If you are using this for a RIMS system, I strongly suggest that you replace the elbow with a larger one, but for just a manual lauter tun, it will do fine as is.

For a RIMS system drill out the hole in the false bottom and thread with 1/2" NPT and buy a 1/2" NPT to 1/2" hose barb nylon elbow. If non-RIMS, buy a 1/4" nylon hose barb to 1/2" Male NPT straight fitting, for RIMS, buy 1/2" NPT to 1/2" hose barb. Take this straight adapter and go to a grindstone or belt/disk sander and grind off the threads from the outside of the nylon adapter doing so in a manner to give you a truncated cone shape like a rubber stopper. This is so that it will fit snugly into the reducing bushing which is part of the bulkhead fitting.

With either the 1/4" or the 1/2" version, you now have a false bottom sitting on the bottom with an elbow sticking up out of it, and a bulkhead fitting with a nylon adpater sticking out of it, both of which have hose barb ends. Now to connect them. Measure the distance between the shoulders of the two hose barbs and cut a piece of clear vinyl, internally braided reinforced hose about 1/8" longer than that distance. Remove the false bottom and the nylon adapter in the bulkhead fitting and insert them into the ends of the pieces of hose. You then angle the false bottom down into the bottom of the cooler so that the nylon adapter begins to enter the bulkhead fitting while the false bottom is still at an angle and not quite on the bottom of the cooler. By the time the false bottom gets to the bottom of the cooler, it should have firmly wedged the conically shaped adapter into the bulkhead fitting. The grain bed sitting on top of this will guarantee it does not move.

Suggestions for RIMS Implementations

As previously mentioned, use 1/2" hose. The reduction of input to your pump will be too restrictive with only 1/4" hose and most magnetically driven pumps can be throttled on the output side, but do not like to be throttled on the input side.

It is possible with heat and suction to collapse regular braided reinforced hose, so I used Teflon hose with Stainless Steel overbraid. This was probably overkill, but it will never collapse on you. You could probably get by with just Teflon. I used just the clear hose for a while and it worked, but with some collapsing causing partial blockage of the input to the pump.


Dion Hollenbeck (619)597-7080x119 Email: hollen@vigra.com
Senior Software Engineer Vigra, Inc., San Diego, California