We call it lemon crack around the Pastry household, and it is — at least for me. It’s one of those foods, which, when it hits my taste buds, sends an arc of electricity straight to my reptilian brain. My pupils dilate, I lose my sense of hearing, then speech recognition, and then all my higher faculties for as long as it takes for me to finish every last drop in the bowl. It’s a serious problem for a baker, one I have with only a few other foods (the others being double-dipped chocolate peanuts and Cheez-Its). Some combination of the sweetness, citrus aromas and richness, all combined in an unctuous texture…I lose all perspective and control.
But what is curd when it’s applied to a sweet substance? People think of curd as a citrus jam, and often treat it like such, giving it to neighbors in jars, spreading it on muffins and such. However it’s actually a custard, of the “stirred” variety, just with lemon juice instead of cream. It’s a “curd” in the sense that like cheese curds, it’s thickened by the action of coagulating proteins. Indeed many Brits call lemon curd lemon “cheese” for this reason. But it’s really nothing like cheese and everything like custard (well maybe not everything)…how so many things get named the way they do I’ll never understand.
The main difference between curd and custard, in addition to it not having any cream or milk in it, is that it contains quite a bit more sugar. This feature allowed the original makers of curds — late 19th Century British housewives — to keep their concoctions on the shelf for up to several weeks. I wouldn’t try that these days, mind you, and indeed it’s their relatively short shelf life that has historically kept curds from becoming as popular as preserves. I suppose its the scarcity that adds to the allure, at least for me…you’re lucky I was able to contain myself long enough to snap a picture.