The idea was actually a throwback to how whiskey used to age. Back when Zoeller’s granny was moonshining, distillers  put their product on barges almost as soon as it went into the barrels. It went in as a clear liquid, and by the time  it reached the final port, the alcohol had spent weeks or months coming into contact with the barrel–and picking up color and flavor. The constant rocking of a ship actually speeds up this process. High temperatures do too.

I did not realize that's how whiskey used to age.