6 egg yolks
1 c. sugar
1/2 c. lemon juice
1/2 c. butter
In a heavy bottom pot over medium heat whisk together the egg yolks and sugar. Add lemon juice and switch to stirring with a wooden spoon, so as to not aerate the curd. Stir continually for 10-15 minutes(longer for larger batches), adjusting the heat as you go to ensure that is does not boil. Your curd is done when it has thickened and heavily coats the back of the spoon. Drop in the butter and stir until melted.
Position a fine mes sieve over a glass or stainless steel bowl and pour the curd through it, to remove any bits of cooked egg.
Pour the curd ( a single batch will make one pint of curd) into your prepared jars, leaving 1/2 inch of head space. If you want to process them for shelf stability, process them in a boiling water canner for 20 minutes(start time when the water returns to a boil). It is best to process only in half-pint jars or smaller, as they allow better heat infiltration. I have also frozen in freezer ziplock bags with success.