WhistlePig 15 Year Rye Whiskey is the culmination of years of patience – a liquid chosen from our finest stocks to be aged for more than a decade. The first WhistlePig product aged in Vermont Estate Oak harvested right from their farm. It is their oldest whiskey. The harsh winters and short growing seasons in Vermont bestow a tight grain pattern upon our trees. Kentucky oak trees are fat. Vermont ones are tight. Tight wood delivers more flavor and depth.