Before the invention of modern electric refrigerators, people used various methods to preserve food and keep it cool. Here are some of the historical techniques that were commonly used:
Icehouses: One of the earliest methods of food preservation involved the use of icehouses or iceboxes. These were insulated structures built partially underground or with thick walls that stored large blocks of ice cut during the winter and stored through the warmer months. The ice would help keep the food and beverages cool, allowing them to last longer.
Root cellars: Root cellars were small underground storage areas or separate rooms built with thick walls and good insulation to maintain a cool and consistent temperature throughout the year. People stored fruits, vegetables, and other perishables in these cellars to extend their shelf life.
Springhouses: A springhouse was a small building constructed over a natural spring or a running water source. The cold water would help keep the interior cool, and people used it to store perishable items like milk, butter, and other foods that needed a lower temperature.
Evaporative cooling: In some regions with low humidity, people used the concept of evaporative cooling. This involved placing food in a container and covering it with a wet cloth. As the water evaporated, it would cool the contents of the container.
Cooling with natural ice: In colder climates or during winter months, people would cut blocks of ice from frozen lakes or rivers and store them in insulated icehouses or iceboxes to use throughout the year. Sawdust or other insulating materials were used to slow down the melting process.
Cooling cabinets: Some cultures and societies constructed cabinets made of materials that were good conductors of heat, such as stone or terracotta. These cabinets would be soaked in water, and as the water evaporated, it would cool the interior, helping preserve perishable items.
It's important to note that these methods were not as efficient or reliable as modern refrigeration systems. The invention of the electric refrigerator in the early 20th century revolutionized food preservation and significantly improved public health by reducing food spoilage and the risk of foodborne illnesses.