Lemon Curd

Ingredients

• 4 large egg yolks
• 2/3 cup (134g) granulated sugar
• 1 Tablespoon lemon zest (about 1 lemon)
• 1/3 cup (80ml) fresh lemon juice (about 3 lemons)
• 1/8 teaspoon salt
• 6 Tablespoons (86g) unsalted butter, softened to room temperature

Instructions

1. Fill the bottom pot of your double boiler with 1-2 inches of water. (Or use the DIY double boiler method listed in the notes.) Place on high heat. Once the water begins to boil, reduce to low heat to keep the water at a simmer.
2. Place egg yolks, granulated sugar, lemon zest, lemon juice, and salt into the top pot of your double boiler. Using a silicone whisk, whisk until completely blended, then continue to whisk as the curd cooks. Constant whisking prevents the egg yolks from curdling. Whisk and cook until the mixture becomes thick, resembling the texture of hollandaise sauce, about 10 minutes. If curd isn’t thickening, turn up the heat and constantly whisk.
3. Remove pan from heat. Cut the butter into 6 separate pieces, then whisk into the curd. The butter will melt from the heat of the curd. Pour curd into a jar or bowl and place a piece of plastic wrap directly on top so it is touching the top of the curd. (This prevents a skin from forming on top.) The curd will continue to thicken as it cools. Once cool, the plastic wrap can be removed.
4. Refrigerate the curd for up to about 10 days.

Notes

1. Freezing Instructions: For longer storage, you can freeze the curd up to 3-6 months. Thaw in the refrigerator overnight before enjoying.
2. Thicker Lemon Curd: For thicker lemon curd, replace 2 of the egg yolks with 1 whole egg. This means you will use 2 egg yolks plus 1 whole egg. Keep the rest of the recipe and instructions the same.
3. Lemon Juice: Do not use bottled lemon juice. Use fresh-squeezed lemon juice.
4. Butter: You can use salted butter instead of unsalted butter. Simply omit 1/8 teaspoon salt in the recipe.
5. No Double Boiler? No Problem! If you do not own a double boiler, you can simply place a small heatproof glass bowl over a saucepan– you will cook the curd in the top pot/bowl.
6. No Straining: I don’t strain the lemon curd. The zest is very tiny and has been cooked, so you can hardly detect its texture. It’s really just there for flavor. However, feel free to run the finished lemon curd through a fine mesh sieve if you want to take the extra step.

From: https://sallysbakingaddiction.com/how-to-make-lemon-curd/