Key Lime Ice Cream

Preparation

1. Step 1

   Grate the lime zest; reserve. Squeeze the limes to yield 1/2 cup juice. Place the zest in a saucepan with the milk. Scald the mixture; cover. Remove from heat. Steep for 30 minutes.

   Step 2

   Combine the egg yolks and sugar in a bowl; whisk until pale yellow and thick.

   Step 3

   Fill a large bowl with ice and water; set aside. Return the milk to the stove, and bring to a simmer. Slowly pour the milk mixture into the egg yolk mixture, whisking constantly.

   Step 4

   Return the mixture to the saucepan; cook over low heat, stirring constantly with a wooden spoon, until the mixture is thick enough to coat the back of a spoon, about 5 minutes.

   Step 5

   Remove the pan from the heat; stir in the chilled cream to stop the cooking. Pour through a fine-mesh sieve into a bowl set in an ice-water bath; stir occasionally until cooled. Stir the reserved lime juice into the custard. Cover; chill at least 30 minutes or overnight.

   Step 6

   Pour the custard into an ice-cream maker, following the manufacturer’s instructions. Churn until the ice cream is just set, but not hard. Transfer to an airtight container; freeze at least 4 hours and up to 1 week.