Sweet and Sour Meatballs

8 pounds ground beef
8 cups bread crumbs, 1/2 italian and 1/2 all-purpose
1/4 cup chopped onion
1 teaspoon dried mustard
6 teaspoons salt
1/2 teaspoon pepper
4 egg whites, beaten
1 1/3 cups milk

Mix meat and bread crumbs. Mix all other ingredients in mixer, then add to meat. Form into balls and brown.

Sauce:

4 cups unsweetened pineapple juice
2 cups brown [...]