Gin is a clear distilled spirit flavoured with a variety of herbs, roots and spices, known as botanicals. In the UK and EU, in order to be called a gin a spirit must have a minimum strength of 37.5% alcohol and juniper must be the dominant botanical. Gin production starts with a neutral base spirit. Usually, this is a spirit distilled in a continuous (column) still to a very high percentage of alcohol (95-96%), although some producers use a pot still or Lomond still. 

The majority of gins are flavoured with at least half a dozen botanicals, although gins such as The Botanist or Monkey 47 use many more. Aside from juniper, classic gin botanicals include cardamom, nutmeg, coriander, cassia, orris root, ginger, angelica, liquorice, citrus peel, star anise and black pepper.

The most popular type of gin is London Dry, a juniper-forward style dry gin made with the classical botanicals. Other classic styles of gin include the historical Jenever, a Dutch precursor to gin often made with malt or grape spirit from which modern gin gets its name, and Old Tom, a sweetened gin style popular in the 19th century.  Many modern gins have a less juniper-heavy flavour profile and the recent surge in gin's popularity has led to an increase in innovation, with new and exotic botanicals appearing all the time.