I <3 Matkas

A matka is a magical invention. In case you don’t know, a matka is a clay pot that is used in India to hold water, and sometimes yogurt or kulfi. It keeps the contents miraculously cold without refrigeration or any electricity. There is seriously no way to describe how good matka pani is after a few hours in the sun. But the reason I actually love matkas is the fabulous scientific reason that the water inside stays cold. Matkas are made to be porous, so if you put them on a stand, you have to put a bucket underneath to catch the drips. Water is constantly passing through the clay of the pot and making the outside wet. This water is evaporating and in order to get the energy to evaporate (the heat of vaporization) it takes heat from the water inside the matka, cooling it. Since water is continuously evaporating from the surface, the water inside stays cool. The water can be kept even colder by wrapping a wet cloth around the matka. This larger surface area contains more water to be evaporated, removing more heat from the water in the matka and cooling it even further. And this was all invented thousands of years ago without any access to what we consider science and engineering today. I laugh every time I fill up my plastic Nalgene bottle from a clay pot that was engineered thousands of years ago and is more environmentally friendly than anything we have come up with since then.