What is a Mason Jar Thumper?

mason jar thumper

Many newer moonshiners are wondering, what is a mason jar thumper? 


Not all moonshiners choose to use a thumper or thump keg but these devices have been commonly used since early settlers first started making moonshine in North America.  

A thump keg is a little component that you can add between a still pot and condenser.  When this little unit is installed in your system, you can distill the output of the pot still a second time without having to rerun the distillate through the stillpot again.  


Without the thump keg, your still pot will create low wine with a 40 – 50% alcohol level in the first run. 


Moonshiners usually rerun the still through the stillpot a second or third time to create high proof spirits.  

But when a thump keg is installed in your system you can create much higher proof spirits without rerunning the spirits.


How Does a Thump Keg Work? 

With a thump keg, the hot vapor that exits the still arm into the wine that is already condensed at the bottom of the thumper once again evaporates before it reaches the condenser.  When the alcohol is vaporized again, the alcohol content increases dramatically.

In most home moonshine kits, there is only one thump keg built into the system.  But moonshiners can choose to install various thump kegs in their system to create a higher proof whiskey in a single run.  


What Does A Thump Keg Look Like?



A thump keg is a very simple device.  It is a sealed barrel, thumper, or bottle with two pipes leading into it. 

The input pipe is usually long so it reaches the bottom of the thumper where liquid cans condensate.  The second pipe is short and acts as an exit for vaporized alcohol to escape into a condenser or a second thump keg.


What Materials Are Used For Thump Kegs?

Thump kegs can be made from various materials.  It all depends on the type of thumper moonshiners have available when making their kits.  It is however important to realize that some materials work better than others.  


When vapors are forced into the thumper, the keg uses waste heat from the still pot to function so gas that condenses into liquid can once again vaporize and rise into the condenser.


 Some thump keg materials are better at absorbing and keeping warm and as a result, these kegs work better.  

 Here is a quick look at some of the different types of thumper kegs you can make or buy;


Glass Thumper

Glass is one of the most common thumper materials because it is so flexible, especially when you use Mason jar thumpers.

 The design of mason jars is ideal for moonshine brewing because these glass jars can easily be removed from the thumper gasket for cleaning or replacing. 

Glass thumpers are also ideal because you can buy thumper kits that fit right on top of mason jars online.


Copper Thumper

Copper is a very popular material in moonshine kits.  This is because copper is a great heat conductor and it helps improve the taste of moonshine. 

Copper also removes some of the sulfur compounds in spirits which allows that fruity flavor to become much more potent in your moonshine.  


Wood Thumpers

Wood thumpers are loved by many moonshiners because wood naturally insulates the thumper keg.  The vapors and liquids that condensate into the thump keg stay warm.  This, in return, causes the liquid to vaporize once again which is necessary for distillation.


How to Build A Moonshine Thumper

Glass thumper kegs are by far the easiest to make and use.  This is first because you can buy the thumper attachment online and mason jars can easily be unscrewed for cleaning or replacement.  Here is how to build your moonshine jar thumper;


What You Need

  • 1/2 gallon mason jar thumper
  • copper mason jar lids
  • mason jar seal
  • Copper piping
  • Copper bend fitting
  • Copper soldering wire
  • Soldering machine
  • Saw


How To Build The Mason Jar Thumper Gasket

Before you can assemble your set, you need to build your Mason jar thumper gasket.  

If you do not have the time or patience to do this then you can also buy complete kits online.  These kits are made of copper and already include the copper piping, copper jar lid, and seal and they are compatible with all mason jars.

You can also make a stainless steel Mason jar thumper gasket.  Stainless steel is just as practical but many prefer copper because it is easier to weld or solder and copper does improve the taste of your moonshine.  


Step 1

First, grab your copper piping and cut them to size.  There should be one long tube and one short.  The long tube should correspond with the length of the height of the mason jar you are using and should reach the bottom of the jar.

  You can solder the copper bend onto the end of the long copper pipe.  This bend should be positioned downward at the bottom of the jar.


Step 2

Now grab your copper Mason jar lid and drill two holes at opposite sides of the plate.  The holes should be just large enough for the copper pipes to slide into.  The copper pipes should protrude from the copper lid by at least 3cm. 


Step 3

Grab your soldering kit and solder the copper wire into the holes of the copper lid.  The soldering should create an airtight seal so take your time to do a good job.

Congratulations, you now created your very own thumper gasket for a mason jar.


Assembling Your Mason jar Thumper

Once your gasket is complete, you can simply assemble it into your mason jar.  It is important to insert the rubber seal between the thumper gasket and glass jar before screwing the lid on tightly so you will create an airtight seal.

Your Mason jar thumper should now be fully assembled and is ready to install in your moonshine kit. 


Final Thought

Once your thumper is complete, you will need to adapt your moonshine still kit.  The thumper should be installed between the still pot and the condenser. 

For a higher quality spirit, you can install more than one thumper keg in your system. 

You can also use your thumper keg to improve the taste of your spirits by adding certain fruits or flavorings to the thump keg.