Ingredients: Bones from an animal, with or without skin and meat; enough water to cover the bones; a splash of vinegar or lemon juice; assorted vegetables and their scraps (optional).
Recipe: Put the bones into a pot. Add cold water to cover the bones. Add the vinegar. Let stand for 30-60 minutes. Bring to a simmer, or of you’re using a crock pot, turn it to “low”. Skim off any fat on the top. Continue to simmer for 6-48 hours for chicken and 12-72 hours for beef. Adding vegetables in the last 30 minutes of cooking will help preserve their nutrients. Strain through a colander and discard the bones.