Strength of Rum at Distillation and Bottling
Most rums on the market are bottled at 80 proof, or 40% alcohol by volume (ABV), but they’re distilled to a higher proof—anywhere from 85 to 95% ABV—and then diluted with water to achieve bottling proof. The rums with the richest flavors and bodies are those distilled to a lower proof—say 85% abv—and then diluted to a higher proof—say 43 to 45% abv.
Why is this so? When spirits are distilled to higher and higher proofs, they lose the esters and congeners that build flavor; a rum that comes off the still at 95% ABV will retain fewer flavor compounds than one distilled to 85%. Remember, a spirit distilled to 95% ABV is 95% alcohol and 5% other things. Some part of that 5% is flavor molecules. A spirit distilled to 85% ABV has 15% other things, and therefore more room for flavor molecules.
When you take a rum distilled at 95% ABV and dilute it down to 40%, you need to add a lot of water, which, being water, carries no flavor. So you end up with a lighter tasting rum than if you start with a more flavorful spirit and add less water.
