The first time I ever heard anything about bone broth was on the Sufficient Self forum. I figured it was just boiling up the leftover bones from chicken or turkey to make stock. I was wrong.
According to the knowledgable people on that forum, you need a glug of ACV in with the water and bones to make bone broth. The vinegar pulls out the nutrients from the bones and makes the most yummy tasting broth! It looks much richer than the pale, watery stuff I used to make (that I thought was so good) or the really pale stuff you get from Swanson's in the grocery store (which is just a step up from plain ol' water). An added bonus is that if you cook it long enough, the bones get really soft. So soft that you can take the leg bone and just mush the end of it between your fingers. And no, you don't taste any vinegar.
The first time I tried it was in my old pressure cooker. I used turkey bones. Holy momma, that was good stuff. To make the bones soft enough that I felt safe in mixing them with homemade dog/cat chow, I had to pressure cook it for 2-1/2 hours. I loved the idea of using the bones, but not the idea that I had to have the range on for that long.
The next time I just did it all in my big slow cooker. I used chicken bones that time. Plunked them all in the Crock Pot, added water to cover and a glug of apple cider vinegar (a glug is a technical term used in some kitchens). I put the cooker on low, and forgot about it until the next day. When I checked it, all the bones were easily mushing up. Since this batch was just for dog/cat food, they got all the broth and marrow-y goodness from the mushed bones. All the four legged critters gave it two paws up!
I'm already saving chicken bones in the freezer for the next batch. I'll keep the rich broth for a pot of chicken and noodles this time. Who knew that simple ACV could make such a difference?
If you have never cooked with stock or bone broth, you're in for a treat. Once you start using it, you'll never go back to using water.
I found this great site that lists more details on how to make bone broth with beef, chicken and pork bones: