The Old Fashioned is the cocktail with the fewest moving parts: whiskey, sugar, bitters and a little water. That is exactly the 1806 description of a "cocktail", and the drink is basically that recipe, kept alive. It is simple to make and easy to get wrong, because with only four things in the glass, the balance between them is everything.

The spec, and how to make it

The IBA (the International Bartenders Association) lists 45 ml bourbon or rye whiskey, one sugar cube, a few dashes of Angostura bitters and a few dashes of plain water. Many bars pour 60 ml (2 oz) and use a teaspoon of rich syrup (two parts sugar to one part water) instead of a cube, which is what the calculator above starts with. Both are fine; the 60 ml version is a bigger, stronger drink.

1. Put the sugar (or syrup) in a rocks glass and add 2 dashes of bitters. If you use a cube, add a few drops of water and muddle, which means crushing it with a spoon or muddler, until it dissolves.
2. Add a large ice cube or a few big cubes, then pour in the whiskey.
3. Stir slowly for about 20 to 30 seconds, until the glass is cold and the drink has lost its sharp edge.
4. Squeeze a strip of orange peel over the top so the oils land on the surface, rub it round the rim, and drop it in. A cocktail cherry is the classic extra; the IBA lists it as a garnish too.

Serve it in the glass you made it in. Measures vary between books, so if a recipe looks different, it is usually the sugar amount or the whiskey size, not a mistake.

Why it works

An Old Fashioned is a spirit drink with a tiny amount of sweetener, so it only needs to be cold, a little diluted and a little sweet. Each part has a job. Sugar softens the burn and brings out the vanilla and caramel in the oak. Bitters act like salt in cooking: a few drops add spice and a dry edge that stops it tasting sugary. And the water, from melting ice, is the part people forget. Straight from the bottle, whiskey at 40 to 50% alcohol is hot on the nose and tongue; a little water opens the aroma and makes it taste rounder.

That is also why it is stirred, not shaken. There is no juice or egg to blend, so shaking would only make it cloudy and over-diluted. Stirring chills and dilutes gently and keeps it clear and silky. Use big ice because it melts slowly: small or wet ice would turn the drink to water before you finished it. Try the stir-time slider above: short stirs leave it strong and sharp, very long ones push the strength down towards thin.

Whiskey, sugar, bitters, water: the 1806 recipe, still working.

A short, honest history

In May 1806, the editor of a New York newspaper called The Balance and Columbian Repository described a cocktail as a mix of spirits, bitters, water and sugar. The name "old fashioned" came later, around the 1880s: the term "old-fashioned cocktails" appeared in a Chicago newspaper in 1880, as drinkers asked for the plain, older style of drink instead of the fancier mixtures that had become popular. You will often hear that it was invented at the Pendennis Club in Louisville, Kentucky. Cocktail historians dispute that story, since the drink was in print before the club story begins, so treat it as bar legend.

Variations, including a low or no one

• Rye: spicier and drier than bourbon, so many people use a little less sugar.
• Demerara or maple: use a demerara sugar syrup or a small amount of maple syrup for a richer, toastier sweetness.
• Lower strength: pour 40 ml of whiskey and stir a few seconds less; it is lighter without becoming watery.
• Alcohol-free: use an alcohol-free whisky-style spirit, or strong black tea cooled over ice, with the same sugar and a few drops of alcohol-free bitters. It will not taste like whiskey, but the structure of sweet, bitter and cold still works. Regular bitters are used in tiny amounts, but they do contain alcohol.

What to look for

Two things matter more than any brand. First, ice: large, clear, dense cubes that melt slowly. Second, whiskey you enjoy neat, at a strength of about 40 to 50%, because there is nowhere for a poor spirit to hide. Choose a bourbon or a rye in your usual price range and measure the sugar rather than guessing. As with any cocktail, enjoy it slowly and in moderation; a drink this strong is one to sip, not rush.