The Real McCoy "Distiller’s Proof” are blends of rum that are produced from a combination of Pot still and twin-column Coffey still distillate. The pot still creates rum with a “heavy” flavor profile because it is very inefficient at extracting alcohol, meaning that most of the flavor compounds developed during fermentation remain in the rum after it has been sent through the pot still. Conversely, the Coffey still (invented by Mr. Aeneas Coffey in 1887) is much more efficient at extracting alcohol, meaning that much of the flavor compounds from fermentation are extracted, resulting in a “light” flavor profile rum. These two flavor profiles are blended into light and heavy blends and then aged for 3, 5 or 12 years in American oak, ex-Bourbon casks. Each blend of Distiller's Proof is unique because it is impossible to exactly duplicate a flavor profile when the rum interacts with different barrels, each having its own unique characteristics, and then having many barrels involved in the final blend.