As early as 250 years ago, our ancestors knew how to freeze food with ice, and later learned to make white sugar. This enabled the clever chef to concoct a "strange" food to enrich the emperor's chef in hot summer. This unique food is the earliest popsicle in the world-a "snow stick" frozen with rice oil soaked in essence, milk and sugar. This kind of "snow stick", which was deeply appreciated by the emperor, was imprisoned by the tall palace wall for nearly a thousand years, and it didn't appear in the street with the nickname of "ice stick" until the end of 12 A.D. This is probably because the palace chef made a living after leaving the palace and changed the "snow stick" to "ice stick" to hide people's eyes and ears.