The Sour is a family of cocktails consisting of a spirit, an acid, and a sweetener. The basic recipe for a sour is this:
- 2 oz spirit
- ¾ oz citrus juice
- ¾ oz syrup
Add these to a shaker with ice, shake, and strain into a glass. You can use any spirit, from whiskey to rum to gin; any sour citrus (usually lemon or lime). You can even use a different syrup rather than plain simple syrup, such as honey syrup, agave, or maple syrup.
If you remember that ratio, you have memorized hundreds of possible cocktails. A Daiquiri is a sour made with rum and lime. A Pinkest Gin is gin and grapefruit — though the syrup is reduced to ½ oz due to the sweeter nature of grapefruit juice compared to lemon or lime.
If you want to invent your own cocktail, a sour is a fantastically easy place to start. Many of the obvious combinations are already well known, but use an unusual syrup flavor or the right liqueur and there’s no telling what you may discover. Maybe you could try gin and lemon with a rosemary syrup, or tequila and grapefruit with syrup made from prickly pear fruit—in
Some sours call for the addition of an egg white. This does two things to the drink. First, it foams up during shaking, adding a thicker, slightly creamy quality to the drink. Second, the proteins in the egg binds to the tannins present in aged spirits, such as whiskey, making the flavor smoother. This is why an egg white is added to a Whiskey Sour. When doubling a recipe, one egg white is often enough for two drinks shaken together.
A Fizz is a sour with the addition of something carbonated. Usually that means soda water, but occasionally champaign or beer may be used.
Typically, all ingredients expect the soda water are shaken with ice and strained into a glass. Then the soda water is added.
It is a blurry line that distinguishes a fizz from a Highball. Generally speaking, a highball has more mixer than spirit, and less citrus — if any at all. A fizz also tends to be shaken where a highball is built in the glass. But it can be a subjective call where precisely the boundary lies between the two.
Credit for the six cocktail families goes to Cocktail Codex. I highly recommend it for an in-depth exploration of drink variations in each category