Temperature: We'll bring this almost to a simmer, around 175 degrees Fahrenheit. This will thicken it without changing its composition.
Risk Factors:
A common problem with homemade lemon curd is the eggs curdling, where you end up with lumps of scrambled egg yolks. We blend the ingredients in advance to avoid this issue.
If you cook it too quickly, the butter will become grainy and cause an off taste. We'll be cooking it on low, which will take a while but allow it to thicken without changing the chemistry of it.
You'll need:
- 3 large lemons
- 1 1/2 c sugar
- 1 stick unsalted butter
- 4 large eggs
- A pinch of salt
First, zest the lemons. I swear by my microplane zester, but you can use the small side of a box grater, or even a carrot peeler; just be sure not to get the white part of the peel beneath the yellow part. That will be bitter instead of tasting like lemon, and it'll affect the flavor of the finished product.
Toss the zest into a food processor with the sugar, and pulse it until the zest is totally combined. You'll really get the strong lemon flavor by doing this.
Juice the lemons and put it aside.
Put the zest/sugar mixture into a stand mixture with the butter and blend it together. Add the eggs and blend well. Then add the lemon juice and salt and mix until combined.
Dump the whole thing in a saucepan with a candy thermometer on the side. You want to cook this on low heat to just about 170, which is when it'll start to thicken. It'll get shiny - stir gently with a wooden spoon - and then you'll see it thicken so it's not quite liquid anymore.
Remove it at 170 - it'll thicken more as it cools.
Put in an airtight container and refrigerate. It'll get really thick so just stir it when you're ready to use!
