A really good stock will turn gelatinous when chilled. If your cooled broth has become one solid lump after a night in the fridge, you have done a good job. No worries, the broth will promptly liquefy again with just a little warmth.
Vegetable Beef Soup: Add diced carrots, celery, green beans, one small can of tomato paste, one tin of plain tomato sauce, dried basil and beef cubes to 2-3 quarts of homemade beef stock. Simmer until beef is cooked and tender.
Why do I need to add vinegar? The apple cider vinegar added in the beginning of the recipe helps leach the nutrients out of the bones and into the broth.
How hard should I boil it? A rolling boil is not recommended. Bring the pot to an initial boil and turn the heat down to a gentle simmer. Too much boiling will break down the collagen in the bones or chicken feet. A gentle simmer will help bring the collagen into the broth.
Stock Cubes: pour cooled stock into an ice cube tray and freeze. Store cubes in zip lock bag in freezer and use when ever you need a few tablespoons of stock.