A new kind of
ice cream, invented in the 1940s, that could be fast-frozen on the spot, and didn't require the sort of freezing and preparation needed by traditional ice cream. The invention of the soft-serve freezer led to the foundation of the
Dairy Queen restaurant franchise.
In the early days, customers were mystified by the way soft-serve flowed into their cones like liquid yet was solid when they took a bite. A variety of rumors circulated about the reason; one DQ operator of the day confided that his favorite rumor was that the mix contained plaster of Paris.