The single most important non-spirit in your liquor cabinet.

Almost every cocktail in our library calls for simple syrup. Margarita. Daiquiri. Tom Collins. Mojito. Whisky Sour. The unsung sweetener that holds the whole drink together. And almost no recipe ever explains it.

It is sugar and water. That is it.

The two ratios: 1:1 vs 2:1

1:1 simple syrup is one part sugar to one part water by volume. 250mL water, 250g caster sugar. Heat just until the sugar dissolves, never boil. Cool. This is the standard in most American cocktail recipes and modern bar manuals. It is light, fast, and goes off after about a month in the fridge.

2:1 rich simple syrup is two parts sugar to one part water by volume. 250mL water, 500g caster sugar. Heat gently. This is the British and tiki standard, called “rich syrup” or “demerara syrup” depending on the sugar. It tastes more sugar-forward and lasts longer (up to three months refrigerated).

Which to use: if a recipe just says “simple syrup”, assume 1:1. If a recipe is from Trader Vic, Beachbum Berry, or any tiki book, assume 2:1. If a recipe is for a sour (Whisky Sour, Daiquiri, Margarita), 1:1 is right. If a recipe is for a tropical or modern stirred drink (Mai Tai, Pina Colada), 2:1 gives more body.

How to make it

Combine sugar and water in a small saucepan. Stir over the lowest heat until the sugar fully dissolves, about two minutes. Do not let it simmer or boil, that drives off water and changes the ratio. Cool completely before bottling. Keep in a sterilised glass bottle in the fridge.

The cold-water shake method works too: add equal weights of sugar and water to a sealed jar and shake hard for two minutes. Slower but no stove.

Six flavoured syrups worth keeping in the fridge

Rosemary syrup. Add 4 sprigs of fresh rosemary to a 1:1 batch while it cools. Strain after thirty minutes. Lasts two weeks. Use in a gin & tonic, a French 75, or a Whisky Sour.

Vanilla syrup. Split half a vanilla pod, scrape the seeds in, drop the pod in. Heat with sugar and water as normal. Strain when cool. Use in an Espresso Martini, a Painkiller, or any rum drink.

Honey syrup. Three parts honey to one part hot water, stirred until smooth. Use anywhere a Bee’s Knees, Gold Rush, or Penicillin recipe asks for honey syrup. Lasts a month.

Ginger syrup. Slice 50g of fresh ginger thin, simmer with 250mL water for ten minutes, strain, then dissolve 250g sugar in the strained liquid. Use in a Moscow Mule when you want more bite, or a Penicillin.

Demerara syrup. Replace caster sugar with demerara (raw sugar) at 2:1. Toffee-coloured and richer-tasting. Use in an Old Fashioned or a Mai Tai.

Spiced syrup. Add 4 cloves, 1 cinnamon stick, 4 cardamom pods, 2 strips of orange peel to a 1:1 batch. Strain after twenty minutes. Use in mulled cider, hot toddy, or autumn cocktails.

Storage

Always sterilise the bottle (boiling water rinse, dry on a clean tea towel). Always refrigerate. 1:1 keeps about a month, 2:1 keeps three months, flavoured syrups keep two weeks. If you see any cloudiness or smell anything off, throw it out. Sugar inhibits a lot of growth but not all of it.

The cheat that bartenders use

Caster sugar (superfine) dissolves in cold water if you shake hard enough. Pre-batch a Daiquiri or Margarita with caster sugar, lime, and rum/tequila in the shaker, shake with ice for fifteen seconds, and you have skipped the syrup step entirely. Works for citrus drinks. Doesn’t work for stirred or tiki drinks.