Navy strength, or gunpowder proof as it also known, is entrenched in the history of rum. In times past, pirates and sailors used rum as currency for goods, slaves and money.

To ensure a worth product was being used in the transaction, a simple test was conducted as ‘proof’ of the strength of the product.

A small pile of gunpowder was placed on the ground and doused with a healthy dose of rum. A lit match was then used as judge, jury and executioner… If the match extinguished, then the rum was watered down (as the sailors tried to stretch out the goods), and if the powder ignited the product, then it was overproof (over 57%) and worth of the transaction. If the rum was under-proof, the pirates would likely kill the traders and still take the rum!