Gin. Legally, it must be a flavoured ethyl alcohol-based drink with 37.5% ABV or above. The predominant element in the flavour must be juniper. That’s pretty much it. There are distinctions and categories, some official, some not: London Dry Gin, Old Tom, Navy Strength. There is thus a massive scope for experiment and variation in gin, as anyone who has shopped for gin lately well knows.