Ethan and I are both suckers for East and Southeast Asian ingredients and like to look to groceries in Chinatown for inspiration. After some experimentation, we settled on this sorbet: a refreshing but full-bodied rejoinder to heavy, spiced meals or summer heat.
Kaffir limes hail from Southeast Asia and are used in both sweet and savory dishes. Their leaves are full of intense aromatic oils, mustier than other limes. The robust leaves can also handle longer cooking, making them perfect to steep into a syrup. If you can't find them, lime zest is a decent substitute, but they're easy to find at well-stocked Thai or Cambodian markets. Frozen, they last indefinitely.
The base liquid for this sorbet is coconut water. Coconut water is the natural juice of a young, green coconut—what you get when you crack one open. Coconut milk is made by soaking and puréeing the meat of mature coconuts. It's much thicker and sweeter with a higher fat content, and is often used to replace dairy in vegan ice creams, though when frozen, it can get a little grainy. We chose coconut water here because of its fresh, bright flavors, which pairs beautifully
with ginger and lime.
Star anise contributes more depth of flavor, elevating this from a citrusy ice to something more exotic. You don't need much, and it doesn't need to steep for very long to impart its flavor. The coconut water base is subtle and anise easily overwhelms everything it touches. But when your flavors are balanced, you'll be rewarded with a dessert that's bright and exotic, with a tinge of gingery heat and a kiss of licorice sweetness.
A bit about sorbets: they're frozen, whipped syrups, and a good sorbet will have a creamy, scoopable texture despite being dairy- (and fat-) free. While dairy ice creams derive their creamy texture from fat, sorbets stay soft thanks to significant quantities of sugar. The sugar dissolved in the sorbet base lowers the freezing point of the base and creates a crystalline molecular structure that creates and holds tiny air bubbles, like a foam.
When testing this recipe, we used a refractometer, a spiffy device that measures the concentration of sugar in a solution. To get a creamy sorbet, you should aim for a concentration 30 parts-per-million. That can be a little sweeter than you'd like, but adding some lemon or lime juice at the end can bring some tartness
back to the sorbet without sacrificing texture. If you don't want to invest in the lab equipment, a cup of white sugar per quart of unsweetened liquid will do the trick.
Special equipment: ice cream maker
Ingredients
serves 6 to 8 (makes about 1 quart), active time 30 minutes, total time 1 1/2 hours, plus chilling time
3 1/2 cups of coconut water (not coconut milk)
12 kaffir lime leaves, slightly bruised in your palm
2 small pieces of star anise
1 tablespoon of ginger, shredded on a fine grater or microplane
2 to 3 tablespoons of lime juice, to taste
1 cup of sugar
Procedures
1. Put the coconut water, kaffir lime leaves, and a tiny pinch of salt in a saucepan and bring to a bare simmer over medium heat, uncovered. Take your time with this and start with cold ingredients—more aromatic flavors will be extracted that way.
2. When the pot is just bubbling and the leaves have faded to a dull olive green, take the pot off the heat and remove them. Stir in
the sugar till dissolved and add the star anise.
3. Let the anise steep in the pot for ten to twenty minutes. The timing here isn't critical and is largely based on how much anise flavor you want in the final product.
4. Transfer the pot to an ice water bath. To cool it down especially fast, run a thin stream of cold water through the bath and put an ice pack in the pot. If you're using a freezer bowl style of ice cream maker, you may want to chill the mixture further in the refrigerator to ensure that it'll churn properly.
5. When chilled, stir in the ginger and two tablespoons of lime juice. Give it a taste; if you want a little more tartness, add the last tablespoon of juice. Otherwise transfer it straight to your machine and freeze according to your manufacturer's instructions.
6. The sorbet's texture improves after an hour or two in the fridge. Some potential toppings: lime zest, grass jelly cubes, or tapioca pearls.