"If I could use my solar cooker for only one thing, it would be for canning," says Eleanor Shimeall. "Processing in a solar cooker is much simpler than conventional methods. It takes me about 10 minutes of preparation time starting from a bowl of fresh fruit to placing the jar in the cooker. An added bonus is that the benign heat of the sun does not destroy the jewel-like colors of the fruit." She says she uses canning jars or jars such as those used by commercially prepared spaghetti sauce, which have a rubber ring bonded into the inside of the screw-on cap.