Today, refrigerators are a common household item, but 300 years ago, when there were no machines to cool things, people still knew how to make and store ice and cold treats. They used natural weather conditions, various techniques, and simple chemistry to enjoy ice and delicious desserts like ice cream even in hot weather.
Ancient Yakhchal Technique: Ice in the Desert
In ancient Persia (modern-day Iran), people built large dome-shaped structures called “Yakhchal”. These buildings had thick walls made of clay, sand, ash, egg whites, and animal hair, which acted as natural insulation.
Water was stored inside these structures. The cool night air and evaporation would freeze the water into ice. Yakhchals were so efficient that they could preserve ice even during the hottest summer months, making cold treats available year-round.
In ancient times, these Yakhchals were used to store ice throughout the year.
Using Salt and Other Compounds
People also discovered that adding salt or potassium nitrate to ice could lower its freezing point. When this mixture became extremely cold, it was used to make ice cream and kulfi. Milk was poured into metal molds and surrounded by salted ice to freeze it.
This technique was widely used in Mughal-era India, where kulfi and other frozen desserts were popular.
Using Natural Resources
-
Ice was cut from frozen lakes and ponds and stored in ice houses, where insulation kept it from melting even in summer.
-
In some regions, water was left in open trays at night. The cold night air would freeze the water, which was then used for cooling and making desserts.
Before modern refrigerators and freezers, people learned to make ice and frozen desserts using natural resources and simple chemistry. Ancient Yakhchals, clever use of weather, and salt mixtures allowed them to enjoy ice and ice cream without any machines.