This is a naturally occurring compound that originated from the unripe berries of the Rowan Tree. Sorbic Acid is made commercially all over the world by using crotonaldehyde and ketene to make it. The material is solid when produced, but it is completely water soluble and melts down remarkably well.
In practice, Sorbic Acid is used to preserve foods from spoilage. One thing that the acid excels at is inhibiting mold growth, which can help to keep many foods safe for much longer than they would be without the acid. Because Sorbic Acid is registered as safe by all major health organizations, it is produced in large quantities and is used heavily in the worldwide food supply. Sorbic Acid is a preferred method of food preservation (as opposed to nitrates) because it is natural and does not have any significant side effects, although a small percentage of the population may be allergic.