What are your favourite bone broth recipes?

Molly Kay wrote:A deeper look on a reddit thread told me there is no set ratio as long as the water covers the bones and any aromatics you're adding, and just cook it down until you get the consistency/richness you want.

I think that about says it all.  It is an art, not a science.

I make bone/veggie scrap broth in my Instant Pot (6qt pressure cooker).  I collect small bones in my freezer - chicken bones, pork and ham bones, really anything other than beef or lamb, which I separate for their own batch - together with veggie scraps - onion tops and skins, root veggie peelings, herb stems, mushroom stems, etc.  Once they have all filled a gallon-sized freezer bag to overflowing, I transfer into a cotton mesh bag and stuff it into the Instant Pot.  It barely fits.  Filled to the Max Fill line, the water (plus a little ACV) just barely covers the bag.

The reason for cooking everything inside a mesh bag is convenient refill.  Once complete, I empty all into a big bowl, then fish out the mesh bag and let it drip drain.  Then back into the Instant Pot it goes, refill with fresh water, and repeat.  The second batch gets mixed into the same big bowl with the first, then strained into storage bottles.

After two broth cycles in the pressure cooker, each lasting an hour of warm up and four hours cook time, I find that bones in the bag can be crushed with my fingers.  They've given all they can give!  The resulting broth is dark, rich, and opaque.  I use it for soup stock, of course, but also to boil pasta and grains and beans.  This double-cycle process always yields just over 5 quarts of broth.