Rum is an extremely complex spirit and there are a host of different types of rum. Like whisky, rum can be made in column or pot stills. It can be made from fermented molasses or sugar cane juice. It’s often labeled as dark or light and frequently contains sugar and coloring. It’s made in a wide number of countries, many of which regulate its production and have specific styles, which vary widely from country to country. In the last few years, rum has been growing in popularity among spirits enthusiasts, many of whom cut their teeth on Scotch or bourbon. More and more consumers are seeking out rums from independent bottlers like Velier and Hunter Laing’s Kill Devil/Golden Devil. At the same time, many craft producers in the US have also been making rum.
For all the growing interest in rum, though, the American regulations have very little to say about it. Want to know what dark and light rum are or what is required for a rhum agricole? The TTB’s spirits regulations won’t help you. If you look at the definition of whiskey in the US regulations, you will find about a dozen different categories described, from bourbon and rye to corn, blended, light, Scotch, Irish, Canadian, etc. If you look at rum, you will find this:
“Rum” is an alcoholic distillate from the fermented juice of sugar cane, sugar cane syrup, sugar cane molasses, or other sugar cane by-products, produced at less than 190° proof in such manner that the distillate possesses the taste, aroma, and characteristics generally attributed to rum, and bottled at not less than 80° proof; and also includes mixtures solely of such distillates.
That’s it. So basically, according to the United States, rum is a sugar cane spirit that tastes like rum. The only other entry is for cachaca which is deemed a distinct product of Brazil governed by Brazilian law. And despite there being numerous different types of rum from different regions, cachaca is the only type or rum which is legally recognized by the US regulations.
The regs do require that, as with any spirit, if a label includes a geographic name (e.g. Jamaican Rum or Puerto Rican Rum), it must actually be produced in that region, but that's a lower standard than recognizing it as a distinct product governed by laws of its country of origin. For instance, in Barbados (and a few other countries), sugar is not permitted to be added to rum. Under the current regulations, if I buy a cask of Barbados rum and add sugar, I can still sell it as Barbados Rum in the U.S., even though it doesn’t comply with Barbados law.
The new TTB proposed regulations, which are aimed at modernizing alcohol regulations, make no substantive change to the rum regulations. Regulations of this type, of course, tend to react to the market. It took 10 to 15 years after the onset of the whiskey boom for the TTB to react to changes in the market with these new proposed regulations, so it’s not surprising that they have yet to address issues in rum, but hopefully sometime in the future, they will.