Basic bone broth recipe

This recipe is a basic bone broth recipe.  It can be easily modified to suit your tastes and by what ingredients you have available in your home.  Of course it is recommended that you use organic meats and vegetable when possible to avoid contamination with hormones, antibiotics and chemical fertilizers.  

3-4 pounds beef marrow, knuckle bones, or chicken carcasses
½ cup raw apple cider vinegar 
4 quarts filtered water 
3 celery stalks
3 carrots
3 quartered onions
1/2 cup of fresh parsley 
Sea salt 

Place the bones in your cooking pot or crockpot, add apple cider vinegar and water, and allow the broth to sit for 1 hour. The vinegar will leach minerals out of the bones and into the broth.  
Add the vegetables and bring to a boil.  After 5-10 minutes skim the thick layer from the top of the mixture and discard it. 
Reduce the heat to a low simmer, cover, and cook for 24-72 hours.  Crock pots are the safest way to cook continually overnight.  If you don’t trust your stovetop it is okay to turn the broth off overnight and then resume cooking in the morning.  
When the broth is almost complete add the parsley for flavor and added minerals.  
After the broth has cooled strain out the bones and other material.  
Add sea salt for taste.
You can store the broth for up to a week in the fridge or 6 months in a freezer.