Distillerymen TJ Kaplan and Dennis Petrakis explain how different qualities and proofs come out of the still at different stages: The first to come out is referred to as the "Head," which has a proof upward of 130, has very little desirable flavor and is potentially dangerous to consume; the "heart" is considered the best quality based on flavor and proof (usually ranging from high 80s to 90s), and the "tail" has a very low proof (around 20) and an undesirable flavor.
