Ginger Grapefruit Curd

From "101 Recipes" food blog online. She simmers the grapefruit juice here so it reduces and concentrates. "The flavor of the curd is better, the color deeper. That said, if you don't have time to do this step, just start with 1/2 cup grapefruit juice, strained. Your curd with still be perfectly good. As far as sweeteners go, I use granulated sugar, or honey, or a blend of the two. I stay clear of brown sugar or maple syrup here just because it muddies the color. What else? Method: I cream, then combine ingredients in a stainless steel mixing bowl here, you can use the bowl from your stand mixer if you like. Then, move that bowl over a saucepan of boiling water (as a makeshift double boiler), to keep the heat gentle. Go from there. It's easy, and keeps bowl-cleaning to a minimum."

• Ready In: 15 mins
• Serves: 16
• Yields: 2 cups

Ingredients

• 1  cup grapefruit juice, freshly squeezed and strained
• 5  tablespoons unsalted butter, room temperature
• 1⁄2 cup granulated sugar (or 1/4 cup honey)
• 2  large  egg yolks, preferably room temperature
• 2  large eggs, preferably room temperature
• 1⁄8 teaspoon sea salt, fine grain
• 1  tablespoon lemon juice, freshly squeezed and strained
• 1  tablespoon  fresh ginger juice (made by pressing grated ginger through a strainer)

Directions

1. Simmer the grapefruit juice in a small saucepan, reducing to 1/2 cup / 120 ml. Let it cool a bit.
2. Cream the butter in a medium stainless steel bowl (note: you'll use this bowl as a makeshift double-boiler later). Add the sugar and beat until fluffy and light. Add the yolks, and then the eggs one at a time, beating well to incorporate after each addition. Stir in the salt, and then gradually add the grapefruit juice, lemon juice, and ginger juice - working the juice in as you go.
3. Rinse out the small saucepan you used earlier, and fill 1/3 of the way full with water. Bring to a simmer, and place your stainless steel bowl of curd on top of it. Stir constantly, and heat the curd slowly enough that the sugar (if you used it) has time to dissolve. This step usually takes me about ten minutes. Pull the curd from the heat when it is just thick enough to coat your spoon - my thermometer usually reads ~166F (it will continue to climb a bit off heat, keep that in mind). Your curd will thick substantially as it cools.
4. There's no need to strain it, unless you somehow ended up with a few lumps (which you shouldn't). And it keeps refrigerated for a week, or up to a month in the freezer. I love it warm or cold.