(from Heidi Swanson)
makes about 2 cups
1 cup/240 ml freshly squeezed grapefruit juice, strained
5 tablespoons unsalted butter, room temp
1/4 cup/60 ml honey
2 large egg yolks, room temp
2 large eggs, room temp
⅛ teaspoon kosher salt
1 tablespoon freshly squeezed lemon juice
1 tablespoon fresh ginger juice (made by pressing grated ginger through a strainer)
Place the grapefruit juice in a small saucepan. Simmer until reduced to ½ cup. Set aside to cool for a bit. Using a handheld electric mixer or a stand mixer fitted with the paddle attachment, place the butter in a stainless steel bowl. Add the honey and beat until light. Add the yolks one at a time, beating well to incorporate, then the whole eggs one at a time, until the mixture is well combined. Add the salt, then gradually add the reduced grapefruit juice, lemon juice, and ginger juice.
Set the stainless steel bowl over a saucepan of simmering water, creating a double boiler. Cook, whisking constantly, until thickened, about 10 minutes. (Curd should register 166 degrees F on an instant read thermometer.) The curd will continue to thicken as it cools. Strain through a fine mesh strainer; cover surface with plastic wrap. Refrigerate. Curd will keep refrigerated for one week, or up to a month in the freezer.