- Reheat oven to 200°C and line a baking sheet with aluminium foil. Roast the bones for 30 minutes. Turn bones over and roast another 30 minutes.
- Once the bones are cooked, place bones in a large stockpot and cover with water. Add the vinegar and allow to sit at room temperature for about 30 minutes.
- Roughly chop the vegetables and add to the stockpot. Heat broth on high temperature until it comes to a rapid simmer. Reduce to low heat and simmer for 12-24 hours. Add water as needed to keep all ingredients covered in water and periodically skim the foam off the top of the pot.
- Allow to cool slightly and strain. Transfer the broth to an airtight container and refrigerate for 4-6 hours or overnight. This allows the fat to rise to the top and solidify.
- The fat can be skimmed off and used for cooking or left in the broth.
- Store in an airtight mason jar or freeze until ready to use. When ready to use, slowly warm the broth over a low heat to bring it back to a liquid consistency.