Beef Stock-Karen

Place 2 to 3 pounds beef cubes, 2 pounds bones and 4 quarts of water in a soup kettle and simmer 1 hour. Skim off scum as it rises. After 1 hour, add 1 cup chopped celery and celery leaves, and 1 teaspoon salt. Simmer 2 more hours. Strain liquid; reserve meat for other uses. Discard bones and vegetable scraps. Let stock cook, then refrigerate.