zest from 1 grapefruit
+ 1/4 cups granulated sugar
In two bowls, divide the egg whites and yolks. Set aside the egg whites from another recipe.
Add the zest of one large grapefruit in with the egg yolks.
In a medium saucepan, add in the sugar, salt, and cornstarch. Whisk until combined.
Add in the grapefruit juice and whisk until incorporated into the sugar mixture. Place saucepan over medium heat and let it come up to a boil. Whisking occasionally.
Once it comes up to a boil, let it boil for 2 minutes. Whisk constantly to avoid burning.
Pour about 1/2 cup of the juice mixture into the egg yolks that you've set aside. Whisk immediately to avoid cooking the yolks. This is tempering the yolks.
Add the tempered yolks into the saucepan with the juice and whisk until incorporated.
Let the grapefruit curd come up to a boil, and boil for about 5 minutes until thickened.
Remove from the heat and add the cold butter. Whisk until the butter is melted and well combined.
Place in a shallow dish and cover with plastic wrap. Be sure that the plastic wrap is touching the curd, otherwise it may form a skin. Let cool completely. It will take 2-3 hours.
Grapefruit Curd https://www.cookiedoughandovenmitt.com/grapefruit-curd-3/