any of us think that food preservation through keeping an item cooled is only something recently discovered and implemented into mainstream households. This is untrue as many European houses have used to have cellars for centuries. In cellars things such as jam and other conserves could be preserved over months and even years if prepared right due to the low temperature of the earth below the topsoil. Even so, you wouldn’t think this could work in a desert over 2 millennia ago right? Well, let me introduce you to the Iranian Yakhchāl.
The Iranian Yakhchāl (Translated as ice pit: “Yakh” being “ice”, chāl being “pit”) was a dome-like structure above ground with storage space for food below ground. The structure was made of very thick, heat-resistant materials made of sand, clay, egg whites, lime, goat hair, and ash layered up to 2 meters, allowing it to maintain a very low and constant temperature. As a result, ice could be stored in it without melting which could then be used to refrigerate perishable items. During winter water would be piped into the structure using an aqueduct and then allowed to freeze. This ice would keep its form through the seasons due to the great insulation properties of the building material as well as being placed deep underground. A system of bâdgirs (Ancient Iranian wind towers) or just holes at the base of the structure would also be used to keep the air in the Yakhchāl flowing. As a result, the air temperature of the structure would be at a constant low, even through the scorching summer days in the desert.
Such a discovery would prove to be greatly important for the population of Iran, which at the time mainly lived off their livestock due to farmland being available only in very rare well-irrigated areas. The Yakhchāl allowed them to store the meat and hard-to-come-by vegetables for much longer periods of time, allowing them to stock up on food for the winter without the fear of it going bad. Technological advances such as these from bright Iranian scholars would give rise to one of the biggest empires ever, the Persian Empire.
I love exploring history for this exact reason. You always stumble across some of the weirdest and most interesting things. The Yakhchāl is a great example of this as its existence is so oxymoronic making it such an intriguing thing to research and learn about. Moreover, this has taught me a great deal about the technologies of the ancient Iranian civilization!
As such, I decided to delve into some of the technologies of the past that make us wonder if we really have advanced that much after all. 480 BC people used a cold structure with ice to store perishable food items. In modern society, we use a smaller, electric-powered cold structure that also has ice to store our perishable food items. The discovery once made by our ancestors that keeping food cold slows its decay has carried through thousands of years to where we are today, essentially still using the technology of a caveman. Overall I think that all of us should look deeper into what we do and how without the bedrock of history and as a result the bedrock of science, most of what we currently know about our world would be completely different.