Without barrels from the U.S., Scotch whisky as we know it could not exist. Nine out of ten casks used to mature whisky in Scotland today initially matured bourbon or Tennessee whiskey. By law, barrels can be used only once for bourbon, but they still have plenty of flavor to give. Thousands of empty used vessels are shipped to Scotland every year to impart delicious sweetness, scented vanilla, and golden honey flavors to whisky destined for the bourbon barrel. Yet, finding scotch aged in only bourbon requires a keen eye.
