Brown 5 pounds of hamburger in pan breaking into very small pieces. 

Pour off all fat. 

Add 2-3 Tablespoons of brown sugar
1/4 cup white vinegar
1 large bottle of ketchup (enough to cover all meat when mixed)

Simmer for 5 minutes and taste.  If too sweet add a small amount of white vinegar.  If to tart, add a small amount of brown sugar.