Not Legal Advice: Some moonshine stills have a "doubler" or "thumper" between them and the condenser. When a thumper keg is added to a still, it halves the distilling time and doubles the final proof of the beverage.
A thumper keg is simply a second pot or jar that helps draw off the hot water vapor, which in turn helps vaporize the alcohol for a type of second distillation. Before the invention of the thumper, the first output of the still would be run through the system a second time to increase the alcohol content of the moonshine.
The "second pot" is called a thumper keg because when steam is run through it, it makes a thumping sound. We found one person that described the sound as "POP! POP! Thumpa-thumpa-THUMP! Pop! Pop!"
Despite state laws making moonshine production legal without a permit, federal law prohibits distilling at home for personal consumption. Federal laws trumps state laws.
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