Whenever we cook a chicken or turkey, I aways use the bones to make stock. Sometimes I’ll roast chicken backs or turkey necks specifically to make stock, but oftentimes the stock parts are the byproduct of other endeavors (sometimes roasting poultry to make soup). Beef stock usually is a separate affair that I roast marrow and soup bones for specifically, but the principles are the same. It’s a simple process that adapts well to whatever you have on hand. I used to make stock by simmering several birds worth of bones in my 25-quart stockpot for a day or more, but these days my 8-quart Instant Pot is much less fuss (and more energy-efficient to run for 24+ hours than our gas range, plus the very real fire safety issues of running too low on water if you neglect the pot for too long).
The bones of one chicken work perfectly in the 8-quart model. When I make turkey stock from the carcass, I usually do it in two batches. One 2.5-lb bag of chicken backs and a package of feet (I always add a package of feet…) makes one batch. Each batch makes about a gallon of stock, which I store in 1/2-gallon mason jars in the fridge. Roasting the bones in advance isn’t absolutely necessary, but it will make the flavor much better, and then you will have pan drippings, which are a sine qua non of good stock in my book. If you are using a chicken carcass, the bones are already roasted, and definitely save every bit of those drippings!
To get all the precious browned bits off the roasting pan (you want to do this), put a little water in the pan and heat up on the stove until you can dislodge the last bit of juices and bits with a wooden spoon. Add this flavor-water to your stock pot.
Rinse the feet well and add them to your stock pot. Add 2 T. of organic apple cider vinegar, 1+ T. of real salt and enough water to reach within 1.5″-2″ of the top of the pot. Ideally, this mixture of bones, salt, water and vinegar would sit unheated for 30 min. The acidified water begins the process of extracting the minerals from the bones. Sometimes I don’t have time for that. It’s more important to make stock at all than to make perfect stock!
Simmer the pot of stock parts (do not boil) for 12+ hours, but definitely at least 5-6 hours. I usually set my slow-cook setting for 20 hours, with the keep-warm setting on after that, which buys me 10 more hours before I strain the stock. (The 140 degrees maintained in that setting is more than enough to keep extracting goodness out of the bones for your stock, and it’s also a food-safe temperature to hold poultry.)