Ukrainian-born, London-based chef Olia Hercules cooked a SAVEUR Supper for us back in October. One of her recipes called for tomatoes. But it was the end of October, and tomatoes had lost their integrity. So she used a fermented tomato recipe she remembers her mom and grandma making when she was a kid.

"My mother and grandmother raised me on soups," Hercules says. One of these soups, duck borscht, calls for fermented tomatoes. "I'm fascinated by how creative those two were with their recipes back then," she says of the tomatoes. Hercules starts the process by halving plum tomatoes and grating them into a pulp. To that she adds a heavy handful of salt (to encourage the fermentation) and fresh cherry tomatoes, which slowly begin to ferment. The process will take less time the warmer it is, but you're looking for the cherry tomatoes to become slightly fizzy and develop a subtle froth. "Don't be scared," Hercules says. "It looks alive, but that's what you're looking for."

Duck borscht is only the beginning. Once the mixture is pureed to a uniform consistency, you can use it wherever you see fit. The thick tomato juice, with its gentle fizz and puckering acidity, can be added in place of the tomato juice in this classic Bloody Mary recipe, a lifechanging move for Sunday brunches. Swap out the can of whole peeled San Marzano tomatoes, make this margherita pizza, and enjoy the deeper flavors within. The simple process produces complex results, and it's all you need to forget what month it is.

See the recipe for Duck Borscht with Fermented Tomato Sauce »