TIPS:
Bake bones first otherwise it will taste weird and will spoil quicker. If you do a roast with meat on the bone like in the old days this is great.
Do not be tempted to pimp it by adding garlic or spices or other veggies. If you use it as a base for soup etc. add them at that stage.
The vinegar sounds odd but is important.
Buy organic
Will keep in fridge in airtight container e.g. mason jar for at least four days or freeze for at least two months.
To make stock cubes reduce water and put in ice cube tray when cool. Cover with PCB-free cellophane.
Can easily make more by doubling or tripling quantities.
Doggies can chew on cow bones; unlike chicken bones they are safe. So an extra treat for fido!