What is a highball?
Highballs are a type of simple cocktail consisting of a spirit and a carbonate served in a low capacity, tall, ice-filled glass (often referred to as a Highball or Hi-ball glass). Ideally comprising 4oz/125ml to 4.5oz/135ml of ingredients to produce a drink with a maximum volume of 9.5oz/280ml including ice, Highballs are best described as short drinks served tall.
Highballs always have a carbonate (tonic, soda etc.) but unlike Rickeys, Collinses and Fizzes, Highballs traditionally do not contain citrus fruit juice, although that convention has been eroded and a small amount of juice is now acceptable in a Highball.
Scotch & Soda, Gin & Tonic, Whiskey & Ginger, Vodka & Tonic and Rum & Coke are all examples of Highballs, as long as they are served in a Highball glass with a maximum capacity of 10oz/295ml . Presbyterian specifically refers to a Scotch whisky, soda and ginger ale Highball, while a Gin Spider Highball is gin and ginger ale with a dash of Angostura Bitters.