My Cousin the Biologist was visiting a few weeks ago, so I took the opportunity to ask him about the cheesemaking mystery I raised a few months ago.
The rabbis, I mentioned, were certain that only kosher milk can be coagulated to make cheese. "Non-kosher milk doesn't curdle." Why should this be so?
His immediate reaction: Disbelief. A contemptuous scowl transformed his face. "Can't be! I'm sure any milk will curdle if you add rennet!"
I assured him that, aside from the adamant Talmudic statement, I had done a bit of research and had found no evidence of cheese made from non-kosher milk (with the possible exception of camel milk cheese, which has only become possible recently due to modern agricultural technology).
Dairy processing is admittedly not his specialty, but he was stumped. He couldn't suggest why only ruminants' milk should coagulate.
Biology grad students take heed: This could be the route to your Ph.D.!