Eli5: How did people make and keep ice in medieval times, and how do we manufacture ice cubes now ?
In: Technology
Before we figured out how to cool things mechanically (refrigeration), ice was harvested in the winter or where there is ice perpetually. It would be cut into large blocks because larger ice cubes melt slower, and transported to ice houses, a type of building partially underground and with lots of insulation, usually straw. Being underground and insulated means the temperature didn’t change much, and you could keep ice for months. Even so, you would put away hundreds of pounds of ice just to have a few dozen pounds in summer. The whole process takes a lot of manual labor and space for a small product, so only the really rich would have ice far away from where it was harvested.
Now, we have machines that can cool water really fast (refrigeration) and can make ice basically whenever we want. Depending on how you want your ice cubes, it’s made slightly differently (tubes of water being cooled, flat sheets of water being broken up, or cold pipes making ice with holes in it), but uses modern refrigeration. Because of how common and cheap to run these machines are, you can get a dozen pounds of ice for a few dollars.
Latest Answers