Ingredients
1 cup fresh Ruby Red grapefruit juice (from 2 grapefruits), plus 3 tablespoons finely grated Ruby Red grapefruit zest
3 large eggs plus 3 large egg yolks
1/4 cup plus 2 tablespoons sugar
Coarse salt
4 tablespoons unsalted butter, cut into small pieces and softened
Preparation
Bring grapefruit juice to a boil in a small saucepan over medium-high heat. Reduce heat and simmer until juice is reduced by half, about 5 minutes. Let cool.
Whisk together eggs, yolks, sugar, grapefruit juice, grapefruit zest, and a pinch of salt in a double boiler or a heatproof bowl set over (not in) a pot of simmering water. Cook, whisking constantly, until thickened, 6 to 7 minutes. Remove from heat, and whisk in butter, a few pieces at a time.
Pour mixture through a fine sieve into a bowl set in a larger bowl filled with ice water, and stir until cool. Cover surface of curd with plastic wrap, and refrigerate until cold, at least 4 hours and up to 2 days.
