This recipe is an alternative to purchasing commercial falernum, which can be hard to find. Many homemade falernum recipes call for fresh lime juice, but they can turn quickly, even in the refrigerator. A common solution to this problem is to infuse rum with lime zest—but we’ve noticed that lime zest does not give a lot of flavor; it smells great, but doesn’t lend much depth. Instead, we make our falernum starting with oleo saccharum—citrus peels muddled in sugar to release their essential oils—creating a potent simple syrup that we then combine with rum laced with toasted spices. This recipe is terrific in tiki or tiki-inspired drinks, like the Test Pilot (page 187), Three Dots and a Dash (page 187), Rum Runner (page 188), Zombie (page 189), Corn ’n’ Oil (page 194), and Chartreuse Swizzle (page 198).
MAKES 3½ CUPS (28 OUNCES OR 828 ML)
FOR THE RUM INFUSION
1 cup (240 ml) rum (use an overproof rum like Wray & Nephew)
40 cloves
1 tablespoon (1 g) allspice berries
15 raw almonds
1½ ounces (43 g) fresh ginger (by weight), or about ¼ cup minced
FOR THE LIME SIMPLE SYRUP
2 cups (400 g) Demerara sugar
1 cup (240 ml) water
6 drops almond extract
8 lime peels
To make the rum infusion, toast the cloves, allspice berries, and almonds in a skillet over medium heat until gently browned. Cool. Then add spices and ginger to the rum. Let infuse covered for 24 hours at room temperature. Strain with a cheesecloth into a jar to combine with the lime syrup.
To make the lime syrup, peel 8 limes so as not to get too much pith (an OXO peeler works better than a typical vegetable peeler here). Muddle peels with 2 cups (400 g) of sugar. Let rest on the counter for 1 hour to express oils from the peel. Pour in 1 cup (140 ml) of hot (not boiling) water and stir until sugar is dissolved. Strain into a jar and add almond extract. Discard peel. Cool.
To make falernum, combine infused rum and lime syrup in a clean bottle or jar. Covered and refrigerated, this will last for several months.