This condensed “low wine” then runs through the spirit still, which turns the wimpy wine into high-powered jet fuel. The first and last portion of what comes out of the still (known as the foreshot and feint, respectively) are too tainted with impurities to be useful. The middle portion, however, is the 62-to-73-percent alcohol sweet spot. Armed with a hygrometer, the stillman diverts the foreshot and feint back into the still for purification. The good stuff, called new make, is what the master distiller’s looking for: clear, pure, and powerful.