Long before freezers, people figured out clever ways to make frozen treats. Around 500 BC, the Persians in what is now Iran built huge dome-shaped underground rooms called yakhchals, which stayed cold even in summer. They packed them with snow brought down from nearby mountains and used it to chill fruit syrups into a slushy dessert called faloodeh.
Across the world in ancient China, emperors enjoyed a treat made by mixing milk with rice and freezing it in metal containers buried in snow. By the 1500s, Italian cooks were freezing sweetened cream this way, and the dessert we now call ice cream began to take shape.
Modern ice cream got a huge boost when someone discovered that adding salt to ice makes it colder. That allowed home cooks to crank ice cream in a hand-churned bucket. Today the average American eats about 9 litres of ice cream a year, while New Zealanders eat the most per person of any country.
