Barrel entry proof is an often overlooked part of the whiskey-making process. Finger Lakes Distilling whiskey enters the barrel at 100 proof (most distilleries use 125 proof). This allows different flavors to develop during the aging process. Because of the higher water content of the whiskey more of the wood s sugars are broken down. The wood sugars created by charring the barrel. This sweetness is evident in the flavor profile.