Temperature for making bone broth in slow cooker I've made bone broth with grass-fed beef bones a couple of times in regular stock pots. Yesterday I tried it in my Hamilton Beach 6-qt Stay or Go Slow Cooker after carefully preparing the ingredients - soaking, roasting vegetables and sitting with the vinegar before adding herbs and turning it on - at the low setting. Last night I noticed - after 7-8 hours - the water was boiling. Continued for 19 hours when (duh!) it occurred to me this could be WRONG!  

I checked a number of Websites, many of which said bone broth should never be boiled b/c, among other things, it causes the fat to be reincorporated in the broth, without being possible to separate it and it could affect nutrients in the broth.  Other considerations: What about taste? I don't care if it's cloudy since it's for helping a family member with health issues - medicinal rather than show off culinary purposes.

I checked with Hamilton Beach folks who said the low setting is for 180 to 200 degrees, yet it boiled continuously. They also said it would turn off automatically after 14 hours; it didn't! I turned off crock pot and now seek advice re whether it's ruined or if 19 hours at the boil is enough cooking time or WHAT? Any feed back is greatly appreciated.
It's almost certainly not ruined, in the sense of being unsafe or undesirable to eat. A higher temperature can actually increase the extraction of collagen, which is generally desirable for stock/bone broth, though it could also damage some nutrients and more delicate flavors. Given the amount of collagen to be extracted from beef bones, a 19-hour cooking time is certainly not excessive, and you could probably go even longer.

The bigger concern is really with the slow-cooker. A noticeable boil, even just a few bubbles, indicates that the actual temperature is probably on the high end of the manufacturer's given range. If an automatic shutoff also didn't work, that might indicate a faulty component; it sounds to me like the heating element might not be shutting off appropriately to maintain an accurate temperature. That may make the appliance less safe to run unattended and will make its behavior less predictable whether you use it for broth again or something else.

Personally, I'd start looking for another slow cooker before you make another batch. But the batch you made should be safe and fine to consume, assuming it's been handled properly otherwise!