My favorite way to add some spicy aromatics to the cocktail is also a great crowd-pleaser: finishing the drink with toasted citrus oils. The really interesting stuff for us in citrus fruits is the lovely oils contained in the skin of lemons, oranges, grapefruits etc. Applying those oils to the surface of a drink is a sure-fire way to get your palate awakened and interested in what’s going on. These oils flame beautifully as well — though not all drinks suit toasted oils — and add a dusky bass note of aroma to the finish. Whiskey-based cocktails like the Manhattan and the Old Fashioned take flamed fruit oil well, as does tequila, but gin and vodka drinks not so much. There really are no hard and fast rules, and there’s only one way to find out if it works for any particular drink.
This simple method of flaming citrus will make you the master of the bar at your next house party. Cut a good-sized cheek of skin from whichever citrus fruit you choose, pare off the pith on the backside of it — it will impart a nasty bitterness to the drink if you leave it on — and warm the skin with the flame from a match or lighter. This is simply to open the pores of the skin, a few seconds should do it. Then, holding the cheek between your thumb and forefingers, snap it over the surface of your cocktail so that the oils are expelled onto it through the flame. It should burst into a dazzling display of flame and flavour, coating the drink with a delicious slick of aromatics. Drop the peel into the glass and inhale deeply before savoring your masterpiece.