Woke up today to find my girlfriend had left the milk out overnight and it had turned dramatically for the worse by the time I was making my coffee. Our apartment is by no means excessively warm so I started to think that, given mesopotamia reaches much higher average temperatures, how were dairy products kept good in the ancient societies that cropped up in that area? Was it likely they just milked the cows every day?
I know meat could be salted to preserve it and "cold rooms" existed in some societies but is there anything in any of the texts anyone has read that might shed more light on this?
Cheese is the traditional long-term storage mode for milk. That souring of milk that you experienced is lactic-acid fermentation, wherein bacteria convert the lactose in milk to lactic acid--and incidentally, make the resulting fermentation product so acidic that it is resistant to other forms of decay. With addition of rennet, careful control of temperature, etc, the milk sours and coagulates, forming curds that get compressed into cheese, then further aged for a stronger flavor. We get different varieties of cheese from different regional bacteria and other additives.