Revenge, patient people tell us, is a dish best served cold. I feel the same way about soup, at least at this time of year. When it gets hot, there are few things that will whet a flagging appetite like a sip of cold soup.
What’s even better, they’re so easy to make. Puree tomatoes, soaked bread, garlic, assorted vegetables and good Spanish olive oil and you’ve got gazpacho. Blend avocado with cold chicken stock and you’ve got the base for something equally grand.
Just as easy, but seen a lot less often, are cold dairy soups — based on tart buttermilk or yogurt. You can make them as simple as grated cucumbers stirred into yogurt or something much more elaborate. And there are few dishes more refreshing.
For the most part, these soups work best as appetizers. I remember one of the first fancy dinners I ever made was for my parents. I labored for a couple hours on a lovely Hungarian cherry soup that Richard Olney had collected in one volume of his “The Good Cook” series. It really was something — you pitted sour cherries, then made a quick stock with the cracked pits (I used a hammer), a cinnamon stick and Riesling, then brought everything together with sour cream and chilled it. Everyone seemed to enjoy it, and I basked in much praise.
But when we were finished, everyone sat looking around at each other, wondering who was going to be the first to ask where the main course was. We went out for burgers, if I recall correctly.
But just because they won’t stand in for a full meal doesn’t mean these soups are in any way slight. Easy to make? Sure. But you still need to pay attention to the details. And they take a certain amount of patience.
Maybe the most important thing to remember: The freshly made soup is little more than a rough draft. Unlike a hot soup, which is usually ready to eat as soon as you’re done cooking, you really need to give cold soups a couple hours to chill before serving them. And you’ll definitely need to go back after the soup’s been thoroughly chilled and fine-tune the seasoning and the texture.
Cold dulls flavor; you’ll almost certainly want to add more salt and pepper and maybe more acidity. Season generously to start and don’t be afraid to add more just before serving.
At the same time, vegetables sometimes give up liquid, which will thin the soup. On the other hand, starches can absorb some of that liquid, which will make the soup thick and muddy. That’s easy to fix, with the addition of a little milk. But it’s better to start with a soup that’s a little thick, because it’s a lot easier to thin a soup than to thicken it.
A dairy background makes an ideal blank canvas for experimentation. For example, blend radishes and their blanched tops with buttermilk, green onions and a little garlic and you’ve got a soup that’s pretty nice — tart and spicy with bits of crunch. Float thinly sliced radishes on top and drizzle with a little green oil made from those peppery tops and you’ve got something elegant enough to start a nice dinner party.