Shake all of the ingredients (except for the lemon zest) hard with ice and strain into an ice-filled rocks glass. Squeeze the lemon zest, shiny side down over the drink so the scented oils spray across the surface. Discard the zest, add the garnish and serve.
New York sourSimply make your whiskey sour as usual, and then pour 25ml of red wine over the back of the spoon onto the surface of the drink, so it rests on the top in a crimson layer. For best results, use something reasonably fruity like a shiraz or a merlot. This also works with port.
Whiskey & ginger sourWhiskey, ginger and lemon are natural partners, so try adding a dash of ginger liqueur – King’s Ginger Liqueur, which was created for King Edward VII in 1903, is top-notch.
Amaretto sourIn this recipe by American bartender Jeffrey Morgenthaler, the bracing whiskey sour reveals a sweeter, more indulgent side thanks to the addition of a splash of amaretto.
Make the 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.