What's inside a ham hock?

I know there’s meat - the meat is obvious. I know there’s bone, the bone is obvious. There’s a big solid tendon, and there’s some fat. And then there’s this other…stuff. It has a texture like very thick gelatin, but a mouth-feel like fat. But unlike fat, it doesn’t melt down when cooked. It’s a whitish sort of a pasty…something. I happen to enjoy it very much, even if I describe it as pasty. But I can’t figure out what it is? Is it some sort of cartilege? Some sort of cushion for the joint? Is it fat that just doesn’t melt down? I can’t figure it out.

Could it be gristle or cartelidge? Are gristle and cartelidge the same thing? I’d think it was the stuff that is inside joints, that helps the joints move without grating on each other?

could it be marrow?

Marrow would be dark and grainy wouldn’t, not gelatinious? I’d wager it’s connective tissue of some kind.

Gristle or cartelidge are one and the same. In some older animals it can also turn to bone.
Marrow is the soft tissue found inside bones. Usually grayish white.

And oh so yummy!

Hmmm…possibly cartilege…but I thought that cartlilege got all tough and nasty when cooked…perhaps a big load of collagen? I know that collagen is basically what you’re describing, but it usually doesn’t appear in large lumps, it’s sort of spread out in the meat.

There’s a very interesting book about the chemistry of cooking – unfortunately all I remember is that the title has something to do with french fries – and one of the things it explains is that you can get different end products when cooking meat if you do it at a high temperature for a short period vs. a much longer time at a low temperature.

Like with pork: roast it at a normal temperature, and you get, well, roast pork. Cook it much more slowly, like simmering it at barely 2OO degrees F., and you’ll end up with pulled pork. Basically the connective tissues (including collagen) simply break down into other things which don’t have the property of holding the meat together.

Which is a long way of say, my guess is that your ham hocks have been through that long, cook cooking process, and your gooey substance is in fact broken down collagen from the cartilege and tendons.
Looked it up: “How to Read a French Fry: And Other Stories of Intriguing Kitchen Science.”