One of the first dessert recipes I developed for Cook’s Illustrated, for the March/April 2016 issue, was posset, an old-time British treat that I hadn’t previously encountered, but which quickly became a favorite of mine—and of our readers. In the Middle Ages, posset was a milky medicinal drink, potable but not especially appealing. Today’s posset is something altogether different: a chilled dessert with an impossibly satiny texture, like the silkiest mousse or pudding, but easier to make since it contains only cream, sugar, and fresh lemon. Without egg yolks, flour, cornstarch, or gelatin to coax it into setting, its transformation into a velvety delight seems like magic. But really, it’s science.
My recipe goes like this: Boil heavy cream, sugar, and lemon zest until it’s reduced to precisely 2 cups and then add lemon juice. Once the mixture has cooled, strain out the zest, portion the citrusy dairy into individual cups, and chill. The lush, buttery-smooth
