Place your chicken bones in a big pot. Fill it with cool water. Bring it to a boil and let it boil for 5 minutes. Then DUMP out that water! Rinse off the chicken and then return it to the pot.

Fill the pot with water and the apple cider vinegar. Let that sit for a little bit while you prepare your vegetables.

Roughly chop the carrots, celery and onions and add them to the pot.

Simmer for 12-18 hours skimming off any foam that rises to the top. The longer you cook it the more concentrated it will become.

Strain the stock and store it in the refrigerator. It will become gelatinous when it is cold. This is a GOOD thing. Don't worry it will melt right back into a liquid when you heat it up. Use it in sauces, soups, gravies or just drink it warm in a cup.

You can take the bones (but not the veggies) and make another batch of stock. Just start with fresh veggies and add more water. It will be weaker than the first batch but still have good nutrition in it. I recommend cooking it as long as you can. Try to get as close to the color of the first batch as you can. It will usually need to reduce by about half what you got the first time.