Bryan Davis of Lost Spirits Distillery just put up a white paper on "trace carboxylic acid & ester origin in mature spirits." It's a good read for anyone interested in the chemistry of maturation in spirits generally and rum in particular. You can read it here.
This reminds me how much I have been enjoying Lost Spirits Navy Style, I've gone through a few bottles, and it is a regular in my mai tais (not white mai tais), most recently tonight. Good stuff.