My family made this sauce when I was young. They froze it in small containers.
Tomatoes carry massive water content that requires extended reduction to concentrate the sugars and acids properly. Simmering this large volume slowly over low heat evaporates excess liquid without scorching the bottom of the pot. Stir the bottom every 10 minutes using a heavy-bottomed stockpot to prevent the tomato solids from caramelizing prematurely.
Onions, green peppers, and celery release considerable moisture when initially cooked in oil. Drain excess vegetable liquid thoroughly before combining them with the beef and tomatoes, otherwise the final sauce becomes watery and dull. Cook these aromatics until the onions turn translucent and soft, usually taking about 15 minutes over medium heat.
Baking soda added to tomato-heavy mixtures neutralizes sharp acidity without requiring excessive amounts of sugar. Whisk cornstarch thoroughly with cold water before stirring it into the simmering liquid to prevent lumps from forming. Cool the finished sauce down to 40 degrees Fahrenheit within two hours if storing portions in the refrigerator for later use.