Pusser’s highly awarded ‘Gunpowder Proof’ is a traditional Royal Navy style rum produced at original Admiralty strength in accordance with the Admiralty’s blending recipe last used when the Royal Navy discontinued its daily ration on 31 July 1970 (109 Proof). Before the invention of the hydrometer, the ship’s purser shutdown claims of watering down the sailors’ daily tot by mixing a few grains of gunpowder to the rum to see if it would burn. If the mixture ignited, the rum was ‘at proof.’ If it didn’t, the purser might find himself tossed to sea.