WhistlePig is one of the biggest success stories of the modern whiskey world. The brand has only been around since 2007, but American rye whiskey has won numerous prices nonetheless. The WhistlePig 15 Y – Vermont Estate Oak is one of their oldest whiskeys, but also the first to be finished in oak that was harvested on the distillery farm. This wood has more rings than the standard American oak used for whiskey, giving it more opportunity to impart deeper flavors.