Sweet, light Barbados molasses, unsulfured home-style molasses, and pure cane juice And, just to be different, aged in a peated malt whisky cask. It’s pretty tasty. Rumbustion, by the way, is a mid-17th Century slang word for "uproar" or "tumult"; a noisy uncontrollable exuberance. It may or may not have been the root of ‘rum’.