Yesterday I described the simple process my wife used to make delicious ricotta cheese. Since she made it from fresh, whole milk, it produced lots of whey. That’s the liquid that separates from the protein solids in the cheese making process. We had a pot of whey sitting in the refrigerator for several days trying to figure out what to do with it, until my wife had the brilliant idea to use it as a soup base.
Just as the ricotta was simple, so is the cream of broccoli soup she made with only four ingredients–onion, broccoli, whey, heavy cream–and seasonings. First, roughly chop 1 large onion and sweat it in a heavy pot with about three tablespoons extra-virgin olive oil until the onion is soft, about 8 minutes. Stir in two large heads of broccoli, the florets divided and the stems peeled and cut into 1/2-inch rounds. Saute a few minutes longer. Then add to the pot 2 cups whey. Bring almost to a boil, then reduce heat and simmer until the broccoli is completely cooked through.
Run the soup mix through a food mill or blender until smooth. Then return to the pot and stir in 1/2 cup heavy cream. Season with salt and pepper to taste.
Do I really need to tell you this is the best cream of broccoli soup ever? You could add some garlic croutons, or a generous dab of sour cream. Perhaps you like other spices–a pinch of nutmeg, maybe? In any case, this is a great way to get another meal out of making ricotta. But as our friend El pointed out in a comment yesterday, you don’t have to use buttermilk to make your ricotta; you can use something else acid, such as El’s homemade cider vinegar, or even lemon juice, which would result in much less whey.
But we like our new whey-based soup. No way, you say?