Bathtub gin

Bathtub gin refers to any style of homemade spirit made in amateur conditions.

[1] As gin was the predominant drink in the 1920s, many variations were created by mixing cheap grain alcohol with water and flavorings and other agents, such as juniper berry juice and glycerin.

In addition, mixing grain alcohol, water, and flavorings in vessels large enough to supply commercial users had to be small enough for the operation to go undetected by the police.

The liquid is kept heated at about 50 °C (122 °F) which slowly evaporates the ethanol to 40% ABV that condense on the inner walls of the outer vessel.

The condensation that accumulates in the bottom of the vessel can then be diverted directly down through a filter containing activated carbon.