As the hot vapor comes out of the still (Fig. Many shiners in fact prefer to use a wooden barrel for the thump keg, precisely because it loses less of this useful heat than would a metal one.

The thump keg, moreover, does this in a very clever manner, utilizing waste heat from the still pot for its function. In the hillbilly still, the thump keg serves the same purpose as this second, spirit still. Most European distillers still use swan-neck pot stills, and will have both a “beer stripper” to distill the wash to the low-wine state, and a second “spirit still” to rectify the low wine to a high-proof spirit. A second, or even a third, distillation is needed to achieve the high alcohol content necessary to make high-proof whiskey or other spirit. Smaller copper pot in center is thump keg.Īn ordinary pot still, without a thump keg, is capable of distilling a wash to only a “low wine”, which will be about 40-50% alcohol. Figure 1, Typical backwoods whiskey still.

The thump keg is one of the most clever and iconic design elements of the traditional hillbilly still whose purpose, briefly stated, is to distill the output of the pot still a second time, without actually having to run the distillate through the still twice. Indeed, some older European stills made use of what appears to be chambers that functioned as thump kegs, so the principle was surely well known to colonists from the British Isles and the continent. While generally associated with the backwoods whiskey still, the thump keg, or “doubler”, is a very old design element that probably arrived with the early settlers and was incorporated into the stills they built on arriving in North America (Fig.

Thumper keg for sale