The aroma and flavor in citrus fruit is concentrated in the oil cells of its peel. Chefs and bartenders often extract this oil along with the juice to add the essence of the fruit to various dishes and drinks. In cocktails, the oil in the citrus peel provides an additional advantage because it can be flamed.

• Always use firm, fresh fruit; the skin will have higher oil content.

• Use large, thick-skinned navel oranges and large lemons; ask your grocer for 95-count lemons (as opposed to juice lemons, which are 165 count).

• Cutting uniformly sized, thin oval peels that flame up well takes control, concentration and practice. First cut a 1/2-inch nub off each end, being careful not to cut into the fruit. Place the fruit on the cutting board with one of the poles resting on the board. Hold it firmly down on the cutting board and, using the paring knife, cut thin oval-shaped twists 3/4 inch by 1 1/2 inches long. The peel should be thin enough that the yellow shows all around the circumference with just a small amount of white pith visible in the center. This type of peel will maximize the amount of oil expressed into the drink and minimize the amount of bitter white pith on the twist.

• Cut twists in a downward motion from the middle of the fruit down to the bottom, following the curve of the fruit and turning the fruit after each cut until you have circled the fruit completely. Then turn the fruit over and perform the same operation on the other half.

• Navel oranges should yield 12 to 15 twists and large lemons, 10 to 12 twists. If the large 95-count lemons are not available, choose the largest lemons available and be sure the skin is fresh and firm; as the fruit dries out, the skin will feel softer and have much less oil.

Now that you have the peels, you can create festive pyrotechnical displays for your guests with the oil present in the skin of lemons and oranges. To flame the oil:

• Hold a lit match in one hand, and pick up the twist in the other very carefully, as if holding an eggshell; if you squeeze the twist prematurely, the oil will be expelled.

• Hold the twist by the side, not the ends, between thumb and forefinger, skin side facing down, about 4 inches above the drink. Don't squeeze or you'll lose all the oil before you flame.

• Hold the match between the drink and the twist, closer to the twist. Snap the twist sharply, propelling the oil through the lit match and onto the surface of the drink. (Be sure to hold the twist far enough from the drink to avoid getting a smoky film on the glass.)

Adapted from The Craft of the Cocktail, by Dale DeGroff (Clarkson Potter, 2002).