Ingredients

1/2 vanilla bean

1 cup heavy cream

1/2 cup sugar

Pinch salt

4 large egg yolks

1 cup creme fraiche

1 teaspoon fresh lemon juice

Preparation

  1. Scrape seeds from vanilla bean into a 2-quart heavy saucepan. Add cream, sugar, and a pinch of salt and bring just to a boil, stirring until sugar is dissolved, then remove from heat.
  2. Whisk yolks in a large bowl until smooth, then add half of hot cream in a slow stream, whisking until combined well. Add yolk mixture in a slow stream to cream in pot, whisking, then cook over low heat, stirring constantly, until mixture is thickened and thermometer registers 170 to 175F, about 3 minutes.
  3. Immediately pour custard through strainer into a metal bowl set in a larger bowl of ice and cold water. Cool to room temp, stirring occasionally, about 5 minutes.
  4. Remove custard from ice bath and gently whisk in creme fraiche and lemon juice until smooth, then freeze in an ice cream maker.