Gather beef bones, water, apple cider vinegar, onion, carrots, celery, garlic, bay leaves, peppercorns, and salt
Roast the bones at 400°F until browned
Place the bones in a large stockpot or slow cooker
Add chopped vegetables, garlic, bay leaves, and peppercorns
Cover with cold water
Add apple cider vinegar
Bring to a gentle simmer
Skim off any foam that rises to the top
Reduce heat to low
Simmer for 12 to 24 hours
Add more water if needed to keep bones covered
Strain the broth through a fine mesh strainer
Discard solids
Season with salt to taste
Cool the broth
Refrigerate or freeze for storage