I use the gnawed on bones for broth, as far as I'm concerned the cooking to make broth takes care of any germs. I do take into consideration contamination from other foods or flavorings, so not all go into making broth. The cooked bones do alter the flavor of the broth.
The way I typically use bones is that I save the bones in a gallon zip-loc type bag in the freezer until it is full. Then I put the bones in the crock pot, cover with water, and cook on low overnight, maybe 14 to 20 hours. You could go an extra day if you wished. Some people put a little vinegar in this to help dissolve the bones, a true bone broth. I don't do that. I strain the bones out of this liquid and freeze the liquid. I use that liquid instead of water when I make the next batch of broth.
No two batches of my broth are the same. I may use different herbs and other flavorings like veggies or different quantities of the same flavorings. Some batches are all raw meat and bones, some contain some cooked bones. Some contain different proportions of body parts, I remember one that wound up with six feet in it, that was thick when it cooled. I never use salt in mine, some people do. There are no hard and fast rules about what has to go into it, just try something and see how it suits you.
The way I typically use bones is that I save the bones in a gallon zip-loc type bag in the freezer until it is full. Then I put the bones in the crock pot, cover with water, and cook on low overnight, maybe 14 to 20 hours. You could go an extra day if you wished. Some people put a little vinegar in this to help dissolve the bones, a true bone broth. I don't do that. I strain the bones out of this liquid and freeze the liquid. I use that liquid instead of water when I make the next batch of broth.
No two batches of my broth are the same. I may use different herbs and other flavorings like veggies or different quantities of the same flavorings. Some batches are all raw meat and bones, some contain some cooked bones. Some contain different proportions of body parts, I remember one that wound up with six feet in it, that was thick when it cooled. I never use salt in mine, some people do. There are no hard and fast rules about what has to go into it, just try something and see how it suits you.