I was reading about this today and went straight to the freezer where I had a bag of two organic roast chicken carcasses waiting for recycling.
What a great idea and to have the slow cooker on all day every day for a week (making the house smell divine) and just top up the slow cooker with water when necessary.
When removing any broth for use, strain it through some cheesecloth or a (spare) reusable coffee filter, so that all the herbs, chicken bits and vegetables stay behind, also producing a clearer broth, then replace the used broth with more filtered water.
Do this for up to a week, extracting every bit of goodness from that chicken carcass then throw it all away and start all over again with a new roasted chicken carcass or whole chicken.
This recipe is for you to improvise. It gives a guide to what you can put in the broth, but you can make an Asian broth by adding fresh ginger, lemon grass, star anise etc
1 whole chicken (or the carcass of a roasted chicken)
4 bay leaves
1 tbsp black peppercorns
1 tbsp white peppercorns
1 large onion, chopped into chunks
2 carrot, chopped into chunks
3 stalks of celery, chopped into chunks
1 or 2 leeks, chopped into chunks
bunch of fresh thyme, sage and Italian parsley, stalks and all
Filtered water
Put the chicken or chicken carcase into the slow cooker then pile in everything else, stirring and mixing together.
Cover with the filtered water and cook on your lowest setting for ONE WEEK.
After 24 hours or so, you may begin using the broth.
As you need it, simply dip a ladle into the broth to remove the stock. Pour it through some cheese cloth or a fine mesh strainer.
Replace the broth with an equivalent amount of filtered water.
If you are using a whole chicken, you can remove the chicken meat as you need it and use it in other dishes, like stir fries, soups or sandwiches.
At the end of the week, strain off any remaining broth, save or freeze, then discard or compost the bones. The bones by this time will pretty much crumble when pressed between your fingers.
The softness of the bones shows that most of the nourishment (minerals, amino acids etc) have leached from the bones into the broth you’ve been enjoying all week.
Wash the insert of your slow cooker and start al over again!