How to Build a Keggle Mash Tun

Beer, one of the most favorite drinks, that has been around for more than thousands of years is a popular beverage around the world. There are wide variety of beer depending on the contents, flavor, aroma, and bitterness.

If you want to build or convert a keg into a keggle, then it is important to learn some of the basics of brewing process. 

If you do not know much about the mashing process or how a keg or keggle works, then scroll the page to refresh on some basics. 

Brewing is the process that converts natural starch from grains to alcohol. The process involves the following steps:


Usually, barley is selected as the grain for brewing beer; but the brewers also have interests on wheat, rice, and rye. During the malting process, the grains are selected, heated and dried. The grains are cracked open to extract the enzymes required for this process.


As you can see, this is the process that we are going to focus on, in this article. You will need to know what happens to your grains in this process; so as to build a perfect model that will suit your needs. This is because, at the end of this stage, you get wort, which you will use to produce alcohol by boiling and fermenting. 

So, basically, mashing is a process in which you soak the grains deeply in hot water (not boiling) for an hour. By doing so, the grains release the enzymes or natural starch in the water. This sweet liquid called wort is drained to use it for the other processes in making beer.


The boiling process involves the addition of hops to add flavour, bitterness, and aroma to your beer. If you are trying to brew at home, you can also check how to add hops and the different varieties of it. But, not all beers have hops added to it.


The Fermentation is the process of fermenting the sugar syrup by adding yeast. There are two types of the fermentation process which results in two different kinds of beers namely ale and lager. This topic is so vast that we did not want to go in detail. By adding yeast to the sugar syrup, alcohol and carbon dioxide are released.

Bottling & Aging:

At this stage, the beer is carbonated either artificially or naturally by the carbon dioxide released by yeast, to obtain your fancy beer. By letting it age for weeks or months, you get to taste your delicious carbonated beer.

This brewing process, as simple as it sounds, also has difficulties. If you are a first-time brewer, don’t worry, we have got your back. By carefully planning and designing a keggle, you can avoid several struggles during the process. But, before that, you must understand the difference between a keg and a keggle. We are going to convert a keg into a keggle, so it is better to know what is what, before beginning with the design part.

Difference between a Keg and a Keggle:

A keg is a container or a barrel that is used to carbonate and store the drink. It comes in different sizes and used as a dispenser too. There are two different types of kegs: corny kegs and sankey kegs.

Home-brewers prefer corny kegs as it is easy to install. 

A keggle is simply modifying of an old keg into kettle.

If you are brewing for the first time, then you must think about investing thousands of dollars in a manufactured brew kettle. A keggle is a DIY conversion of a keg barrel, to use it for brewing purpose. Getting a keg barrel is difficult, but not imposible. It is illegal if you try to rent a keg barrel for a party, and use it for domestic purposes. 

Keggle Mash Tun

As already mentioned above, the mashing process refers to the steeping of grain levels in hot water. This releases enzyme in the water. The single infusion mashing is the easiest type of mashing, which even home-brewers use with kitchen utensils. The successful mashing process involves the maintenance of a pre-measured amount of water and fixed temperature.

This process takes place for one hour in a mash tun, which separates enzymes from crushed malts. These separated enzymes are then utilized for the sparging process, where the natural starch is converted into sugar. This converted keggle Mash Tun can avoid many messes in the kitchen. 

Advantages of Using Keggle Mash Tun:

  • You can brew in large quantities – say 10 gallons in place of 5 gallons. The efforts and time taken to brew both of it are the same. Then why should you not try doing it in bigger batches?
  • You can boil the whole batch at a single time. Without keggle, you will have to perform mashing, sparging and cooling off the wort after boiling process separately. This will create a mess in the kitchen.
  • Sparging can be done safely instead of pouring hot liquid over a strainer in the kitchen. The latter process is risky and also troublesome.
  • All you need is a keggle, tools and some basic knowledge to enjoy the beer without much struggle in the brewing process.

Is a plastic Mash Tun Safer to Use?

This topic is so common these days, as the plastics are proved dangerous and harmful to human’s consumption. Since we have to boil at higher temperatures, the plastic Mash Tun gives rise to some questions like:

  • Will the plastic bottom be able to prevent heat loss? This is a valid question. As the sparging process involves boiling of the liquid in higher temperature to create sugar, it is, therefore, necessary for the container to prevent heat loss.
  • Since used in higher temperatures, the plastic might release Bisphenol A, which is a harmful compound to humans. So, is it harmful using plastic Mash Tun in this case? No. The Plastic mash tun is absolutely safe because it is made up of food-grade materials.

The Plastic Mash Tun is made from coolers. By converting a beverage cooler into a kettle, you get a Plastic Mash Tun.

Here’s how to make one of those:

In some cases, long boiling time is required, which might release a large amount of PBA compounds. This is where steel mash tun comes into play. Steel Mash Tuns are made by converting the keg barrels into keggles.

Let’s see how to build a normal cooler mash tun and also a keggle mash tun in this article. Scroll the page to find the easiest method, which would suit your expenses and timing.

How to Build a Round Cylindrical Cooler Mash Tun?

You can build either round or rectangular cooler mash turn. It will cost around 75 to 150 dollars. You had better use copper or stainless steel components so that your mash tun will not get contaminated.


  • 5 to 10 Gallon Cylindrical Round Cooler
  • Coupler
  • Barb fitting
  • Ball valve and cam lock
  • Washer
  • Silicone gasket and tubing
  • Plumber’s tape
  • Steel supply line
  • Screwdriver, needle nose-pliers, wrenches, hacksaw and awl
  • Hose clamp
  • Gloves, eye protection and masks.


  1. First of all, open the lid of the cooler. You will find the gasket nut on the back of the spigot. Loosen and remove it using nose-pliers.
  2. After removing the nut that held the spigot, remove the spigot as well.
  3. With tape, wrap half of the pipe nipple. Do not tighten it so much, but make sure it is insulated.
  4. Move the gasket to the centre of the pipe.
  5. Screw the lock nut after placing the washer from the untapped side of the pipe, next to the gasket.
  6. Insert the taped side of the pipe through the spigot hole to the outer side of the cooler.
  7. Now, place a ball valve on the outer side of the cooler on the pipe nipple. Using wrenches tighten the ball valve. 
  8. Cut the stainless steel line and remove the plastic tube from it. Instead of a false bottom, you can use this supply line. It will prevent the grains to come out from disconnects.
  9. Fold and seal one end of the stainless braid; keep the other end open.
  10. With one end of the coupler on hose bar fitting, couple the other end to the pipe nipple inside the cooler.
  11. Now, insert the hose clamp through the open end of the stainless braid. Place the supply line on the hose bar and tighten the hose clamp.
  12. Wrap the male and female-disconnects using seal tape.
  13. Check for any leakages by pouring water inside the cooler.
  14. Screw male disconnect to the ball-valve.
  15. After stretching the silicone tubing over the male disconnect, attach the female disconnect to the 90-degree elbow connecting these two disconnects.
  16. Using Cam locks connect male and female disconnects. You can now mash using the plastic mash tun.

Next, let us see how to make keggle mash tun using used keg barrel. Assuming that you have acquired the keg barrel, let us see what else you will require to make this keggle.

How to Build Keggle Mash Tun?

To build a keggle mash tun, you will need the following:


So, what do you need to get started? Here is a look at all the things that will help you make the Keggle mash tun you are looking for.

  • 15.5 Gallon Stainless Steel Keg
  • Weldless Mash Conversion Kit
  • 15″ Folding False Bottom (Optional) 
  • Weldless Sight Glass Kit 
  • Stem Thermometer
  • Stainless Steel or Glass Lid
  • Permanent Marker
  • Tape measure
  • Earplugs
  • Protective measures, gloves and eye masks
  • Sandpaper
  • Drill and ¼ drill bits
  • Pliers, hammers, wrench and twine
  • Screwdriver and nails


  • Depressurize the Keg:

This is the primary step before you start converting the keg into a keggle. As you know, keg is a container that holds the pressure of the carbonated drink. Therefore, it is important that you open the tap using keg coupler and release the pressure. If you skip this step, it might result in danger.

  • Open Valve to release pressure:

If you do not have a tap to depressurize the keg, use a screwdriver to open the valve. This will depressurize the keg. But, we have to give you a fair warning before you use this method. It might let some of your old beer outside while you do perform this method creating a mess to the surroundings.

  • Attaching Marker and Twine:

Use marker and twine to make a circular mark on top of the keg. You can use angular cutting as well. But this is the easiest method out there if you don’t have the tool. Wrap twine’s one end to the valve on top of the keg, and the other end to the permanent marker.

  • Make a Circular Mark:

Now, stretch the marker to the maximum extent of the twine and rotate it around the top of the keg. Make circular marking using a permanent marker.

  • Wear Protective Gears:

Before starting off with the cutting, wear your protective gloves, earplugs, and goggles.

  • Use Metal Blades:

Setup the metal blades and cut the keg. Move slowly and steadily in a circular motion. Change the blades every now and then.

  • Remove the Keg Top:

After cutting the keg, remove the top. Make sure you wear gloves while touching the rough edges of the keg.

  • Smoothen the Edges:

Use sandpaper and grinding stone to smoothen the rough edges. The cut could have left the edges roughened. Make sure to have a smooth finish.

  • Test the Lid:

Place the lit on the top of the keg and check if it fits perfectly.

  • Mark the spot for drilling:

There will be vent holes at the bottom of the Keg. These holes help in not building up the pressure inside while the propane burner is on. In between the holes, measure 3 and ¾ inches and mark from the bottom of the keg.

  • Drill holes:

Drill holes on the marked spot using ¼ inch drill bit. Make sure to do it slowly and check with each pressure you apply. It is easy to expand the hole, but if you have created a bigger hole, then it is not possible to fill it. Your keggle will be damaged in that case.

  • Expand the hole:

Penetrate the steel keg in steps until you achieve a 7/8’’ hole. Sand and grind it to achieve smooth edges.

  • Weldless Mash Conversion Kit:

This kit would be available in stores that supply kits for home brewing. This conversion kit comes with a bulkhead fitting, stainless steel tube, and false bottom.

Installing Mash Conversion Kit:

Install Mash Conversion kit by tightening the bulk fittings after fixing the false bottom. Make sure to check that the false bottom and the bottom of the keg are in similar shape. If the shape differs, the grains might pass on to the wort, thereby creating difficulties while brewing.

  • Install the thermometer:

Create another hole, a little above the burner, on the keg to install the digital thermometer. It is important to not place it near the burner, as the temperature from the burner can affect the readings on the thermometer.

  • Check the Keggle:

Fill the keggle with water and check for any leakages. Seal all the holes and gaskets if there is any leakage. Now, the keggle is ready for your brewing process.

Before the brewing day, check the vent holes at the bottom. If there aren’t any holes, drill few. These holes will prevent the pressure from building up inside the keg.

It is wise to double-check this as it might cause danger if you fail to check it properly. The build-up pressure could cause the onset of fire.

Make sure to maintain the keggle well after every usage. Rinse it off with warm water. Wash the supply line, disconnects and the false bottoms cleanly as it might have the unwanted grains.

After washing it, wipe it off perfectly with a clean cloth. Use a towel to remove any moisture. Do try it at home first. 

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