Rum, Gin and Sailors Getting on the Lash

WORDS ° Ben Davidson

Prior to the invention of the hydrometer in 1816, which measures the percentage of pure alcohol in a spirit, the common way to measure alcohol was the ‘evidence’ test. When rum was being considered for purchase in these early days usually the ship’s Purser, the person in charge of the handling of money, would employ the gunpowder test – where a few grains of gunpowder were added to the spirit in a bowl and ignited with a magnifying glass. If it failed to ignite, it was deemed to have too much water in the mix and was unacceptable. If it just ignited and burned slowly it was proof the alcohol was of a standard strength. If it ignited with a bang it was deemed to be overproof, of a high strength, and perfectly safe to have on board a ship. This was because the spirit needed to be high enough proof that if it spilt on the gunpowder reserves, they would still be useful for the firing of the cannons.

It was after the British invasion of Jamaica in 1655 that the navy started to give a rum ration to the sailors to keep their ‘spirits high’. Sailors were given a daily ‘tot’ of nearly half a pint of overproof rum when the orders of “splice the mainbrace” were given by the officers. During the ensuing years, the rum ration was slowly reduced until in 1970 when the last rum ration was issued, ending a 300-year-old tradition.

Whilst the sailors enjoyed their overproof rum, the officers had developed a taste for English gin. When the rum ration was diluted down with water and lime juice, giving rise to the infamous Grog ‘cocktail’, the officers started to enjoy drinks like the Gimlet and the Pink Gin as healthy ‘tonics’ whilst at sea.

The modern usage of the name ‘navy strength gin’ was revived in 1993 by Plymouth Gin, when they decided to re-launch the Original Strength Plymouth Gin that was 57% alcohol. This re-established their connection to the Royal Navy that had begun in the early 1800’s. Hence the modern designation of ‘navy strength’ and ‘overproof spirits’ has come to refer to the alcohol percentage, above which it is deemed to be ‘full strength’ alcohol.