Place chicken carcass in a large stock pot and add enough water to cover it - about 1 gallon.

Add 2-4 Tbsp apple cider vinegar then let sit for 30 minutes. The vinegar helps soften the bones to better extract the nutrients. You won't be able to taste it at all when the broth is done!

Cover the pot and bring to a boil, then lower the heat to a simmer.

Every 20 minutes or so for the first hour, check the broth. If it has a buildup of frothy foam on the surface, use a spoon to skim the froth off. The froth will make your broth taste bitter. Usually, organic, free-range chicken carcasses produce much less froth than factory-raised chickens.

Once the carcass is no longer producing froth, add the chopped carrots and celery.

Then cover on and leave the pot alone for the next day. You may check the water level and add water as needed so you'll have 1 gallon of broth when you're done.

During the last 30 minutes of cooking, add the parsley, garlic and salt.

After 24 hours, take the pot off the heat and remove the lid and allow it to cool.

Use a collander to remove the large pieces of carcass and veggies and discard them.

Use a fine mesh strainer or cheesecloth to strain the broth. Then package in 2-4 cup portions in freezer-safe jars or bags.

The broth is good for 4 days refrigerated, or several months frozen.