Soft serve is softer than regular ice cream because air is whipped into the product, making it creamier. The origin of soft serve ice cream is a matter of debate.
Soft serve is lower in milk fat than regular ice cream and is produced at a warmer temperature. Soft serve also contains air that is introduced at the time of freezing. The amount of air alters the taste and texture of the product. Soft serve with low quantities of air has a heavy, icy taste and a slightly yellow appearance. Ice cream with a higher air content tastes creamier and smoother and appears white. The optimum quantity of air is determined by the other ingredients and individual taste. All ice cream must be frozen quickly to avoid crystallization. With soft serve, a special machine at the point of sale freezes the product in the appropriate way.