I made a lovely lunch today of kielbasa and cabbage soup. We had about 1/3 cup of red lentils in the cabinet and so I thought I'd toss them into the soup, just for added protein and fiber.

I sliced and browned the kielbasa, added stock, lentils and cabbage and simmered it, covered, for about 30 minutes. When I served the soup though, I noticed that the lentils had sprouted. I hadn't soaked them beforehand, so I'm not sure why this happened.

Does anyone know why they would have sprouted while the soup cooked?