Prevent molding Berries! Swish Berries around in a solution with 1 part vinegar to 10 parts water to prevent molding. Rinse with water if desired, but you can't taste vinegar. Drain and let air dry on paper towel. Store raspberries up to 1 week and strawberries up to 2 weeks. The vinegar kills any mold spores and other bacteria that might be on the surface of the fruit.