It is believed that 3,500 years ago, an Asian traveler set out on a long journey across a hot desert. He probably carried a canteen filled with milk to satisfy his thirst. At that time, canteens were made from the linings of sheep’s stomachs, since they were waterproof.
When the traveler stopped to rest for the evening, he probably found his canteen filled with a solid white mass. This was cheese.
What had happened was that some of the sheep’s digestive juices, or rennet, had probably dried up in the animal’s stomach and had remained there long after the sheep was killed.
The rennet was still in the stomach during its use as a canteen. The action of the rennet upon the milk is what produced the cheese.