I usually make at least a double batch and occasionally make lime or lemon/lime, with a 1:1 sub. If you don’t like green flecks from the lime zest you can either use lime juice & lemon zest or use a really ripe lime (which will be yellow.) It freezes beautifully, I use half-pint mason jars. If you need to defrost a small amount quickly scrape it out with a spoon and then microwave for a few seconds.
Single Double Quadruple
3 oz 6 oz 12 oz unsalted butter, softened
1c 2c 4c sugar
2 4 8 eggs
2 4 8 egg yolks
2/3c 1 1/3c 2 2/3 c lemon juice
1 tsp 2 tsp 4 tsp grated lemon zest
Beat butter and sugar for 2 minutes. Slowly add eggs and yolks and
continue beating. Add lemon juice. Mixture may look curdled at this
point. Transfer mixture to heavy saucepan. Cook over low heat till
butter melts and it looks velvety. Increase heat to medium and cook,
stirring constantly, till mixture thickens (about 15 minutes or when
mixture reaches 170 degrees F). Do not boil. Remove from heat, stir in
lemon peel. Transfer to a bowl. Lay plastic wrap on the surface of the
lemon curd and chill. Covered tightly, this will keep in the
refrigerator for about 1 week and in the freezer for several months.