[1] The filling is made similarly to a Magic Lemon cream pie, by mixing the ingredients without cooking: the proteins of the egg yolks and condensed milk and the acidic lime juice curdle, thickening the mixture without baking.

[3] The recipe is attributed to Borden's fictional spokesperson, Jane Ellison, and includes condensed milk, lemon juice and rind, and egg yolks.

[4] According to the pastry chef Stella Parks, users of the recipe altered it with local ingredients; she describes it as "a stunning reminder of how deeply America's traditions are shaped by advertising".

[5] A "Tropical Lime Chiffon Pie", using condensed milk and egg yolks, is documented in a 1933 Miami newspaper article.

[12][10] A widely reported story claims that William Curry's cook Aunt Sally invented it in the late 19th century.

[3] It was in the 1950s that Key lime pie was promoted as Florida's "most famous treat" and in 1987 as "the greatest of all regional American desserts.