Hello Maria, I am sorry to hear that. The most common reason why the curd doesnt thicken is that the whisking is not continuous and or the butter doesnt fully melt to incorporate.

Hi Marsha, I also did step by step and the curd never thickened 🙁 Was so disappointed as it was for a birthday and I had to go with a store-bought option.

I have literally made this recipe a dozen times now and it comes out perfect EVERY SINGLE TIME. I have a Pinterest board titled tried and true and this lemon recipe lives there rent free.
I wish I could say I’ve brought it to dozens of soirees, but in actuality when I try to leave the house with one, my husband hunts me down and wrestles it out of my arms. Even going so far as to by me mini tart pans and reading up on how to freeze individual slices.
Can’t say enough about it, and can’t say enough about how important it is to whisk constantly for however long it takes to reach a reasonably thick consistency. It’s crucial to getting it to set correctly.

No worries! And it came out just as good anyway. I’m going to leave a other comment regarding my experience baking this.

Hello Monique, I am sorry about the typo. The recipe is for the whole egg and I have now updated the recipe. Again, sorry for the confusion and happy baking!!