Add half the whiskey and 2 ice cubes to a rocks glass. Stir. Add the sugar syrup, Angostura bitters and 2 more ice cubes. Stir. Add the rest of the whiskey and 2 more ice cubes. Stir.
Add 2 more ice cubes, then pinch the citrus zest so the aromatic oils spray over the drink, then drop it into the glass.
Rum old fashioned
The silky-sweet rums of Latin America are particularly good for this – try the amber-coloured Ron Zacapa from Venezuela. Instead of Angostura bitters, try using Angostura orange bitters, and garnish with an orange twist.
Tequila old fashioned
Anejo tequila has lots of vanilla and caramel notes that work very nicely in an old fashioned. For the sweetener, use agave syrup instead of sugar syrup, although agave syrup tends to be sweeter, so you may need slightly less. Garnish with a lemon twist.
Smoky old fashioned
To add a hint of smoke, infuse your sugar syrup. Simply make a 2:1 sugar syrup and while it’s still warm, put a Lapsang Souchong teabag in the syrup and leave to infuse for half-an-hour. Then make your old fashioned as normal.
How to make sugar syrupTo make a 2:1 sugar syrup, tip 200g caster sugar into a saucepan and pour over 100ml water. Stir and heat gently over a low heat until the sugar has dissolved. Leave to cool, then store in the fridge.