How to Make Alton Brown's Lemon Curd
- Add enough water to a medium saucepan to come about 1-inch up the side. Bring to a simmer over medium-high heat.
- Meanwhile, combine egg yolks and sugar in a medium size metal bowl and whisk until smooth, about 1 minute.
- Measure citrus juice and if needed, add enough cold water to reach 1/3 cup. Add juice and zest to egg mixture and whisk smooth.
- Once water reaches a simmer, reduce heat to low and place bowl on top of saucepan. (Bowl should be large enough to fit on top of saucepan without touching the water.) Whisk until thickened, approximately 8 minutes, or until mixture is light yellow and coats the back of a spoon.
- Remove promptly from heat and stir in butter a piece at a time, allowing each addition to melt before adding the next.