Kirsebaersuppe

There are two weeks in July when the cherries come in. Not the sweet black ones you buy year-round from somewhere else, the real ones. Stevnsbaer, the dark sour cherries that grow along the chalk cliffs on the eastern edge of Sjaelland, small and tart and almost black when they're ready. For those two weeks, Danish kitchens smell of cherries and cinnamon and sugar, and one of the things that comes out of all that cooking is kirsebaersuppe.

This is Denmark's answer to summer heat. Where potato soup belongs to the dark evenings of October, cherry soup belongs to the long bright ones of July, when the light doesn't leave until after ten and you want something cold and red and alive on the table. You simmer the cherries gently with cinnamon and vanilla and lemon, thicken the soup with potato starch so it takes on a silky body without losing its clarity, and chill it until it's properly cold. Then you spoon soft whipped cream into the center of each bowl and watch the cream swirl through the ruby like weather.

The one thing I want you to pay attention to is the potato starch. Kartoffelmel is the Danish pantry thickener, and it behaves differently from cornflour. It goes into cold water first, always, and it thickens the soup the moment it touches the heat. Once it's in, the soup can't boil again or the starch breaks down. I'll walk you through the moment so you get it right the first time. The season decides when you make this. The cherries tell you they're ready. You'll know when it's right.