Although gin has been enjoyed in the UK since the 17th century, London Dry Gin did not emerge until the 19th century along with the invention of the Coffey (column) still. The Coffey still enabled alcohol to be distilled cheaply and efficiently whilst ensuring quality. This meant that the new spirit didn’t require to be sweetened to disguise the taste as previously was done with most gins.
Gin does not have the same geographical restrictions that other spirits such as cognac, Scotch whisky or tequila do meaning that a London Dry Gin can be made anywhere in the world.
The name refers to the style as opposed to the location and is a mark of quality for many. Although it can be made anywhere in the world, there is an EU legal definition of a London Dry Gin.
Firstly, for a London Dry Gin, the base spirit must be distilled to a completely neutral spirit of 96% ABV and must be distilled using natural botanicals. The distillate coming off the still must be above 70% ABV and nothing can be added post-distillation except water and a tiny bit of sugar. When bottled, the gin must be a minimum of 37.5% ABV to be classed as gin.
As nothing can be added, all the flavour must be imparted through the distillation process and the predominant flavour must be of juniper.
Many London Dry Gins also include spices such as coriander, angelica and orris root along with citrus but this is not a requirement to be classed as London Dry.
A London Dry should also be clear and not be coloured in any way.