Rinse your beef bones, pat dry, and place on a baking sheet. Roast at 400 degrees for about 10-15 minutes.
Move the bones to the Instant pot. Add in about 8 cups water and apple cider vinegar.
Seal the lid and set to cook on high pressure for 2 hours.
Remove the lid and add the onions and carrots. If you are using celery and bay leaves add them as well.
Secure the lid and set on high pressure for another 2 hours.
Once the 2 hours are up, release the pressure and check the broth. If you want, you can always set it for another hour or 2, but this time will give you great flavor.
Strain out the veggies and bones.
Cool the broth in an ice bath. I do this by having my broth in a metal bowl. Add about 4 cups of ice to a larger bowl and place the metal bowl on top.
Stir occasionally until it has cooled. Store in an airtight container in the fridge or freezer.