Garnish with the 1/2 lime that has been squeezed using the fruit tongs, and the cocktail is ready to be served.
This cocktail is a variant of the historic cocktail, the Moscow mule, conceived in 1941 in a New York bar, the Chatham, where two entrepreneurs on the street, Martin and Morgan, met to try to revive their respective activities as a vodka distributor and producer of ginger beer.
Kentucky mule is also served in copper mugs, like the original cocktail.
Often Kentucky mules, like Moscow mules, are served with a cucumber garnish. The rule dictates that something is used on the edge of the glass that recalls the ingredients of the cocktail. The use of cucumber is a reference to the Eastern European tradition, in which pickled gherkins are paired with frozen cocktails.
Assuming that this is the variant of an historical IBA cocktail based on vodka, it can be prepared by replacing the base spirit with other spirits. The twist with gin is called London mule, which is one of the best known.