Place the bones in your pot or slow cooker and cover it with water by a few inches. Add the vinegar and let it sit for 30-60 minutes. Bring to a boil, then turn down to a simmer.
While it simmers, you can use a spoon to skim off any scum that rises to the top. Reduce the heat, cover, and allow the broth to simmer very gently. Cook on low heat for at least 6 hours or overnight, to extract the most gelatin and nutrients from the bones. A few hours before it is done, throw in the vegetables, sea salt, and herbs, if you are using them.
Remove from the heat and let it cool. Pick out the heavy bones and discard them, then strain the broth through the mesh or cheesecloth over another pot. When the broth is cool, ladle it into glass mason jars with 2 inches of space left at the top.
When the stock is cooled down, it should wiggle like jelly because of the high gelatin content from the collagen. Don't worry! When you warm it up, it will liquefy again.