Marinara sauce, or tomato sauce, is used in many Italian dishes, including lasagna, spaghetti and even pizza. Because tomatoes are an acidic fruit, the sauces made from them also are acidic. The high acidity can cause upset stomach, heartburn and acid reflux, according to the Mayo Clinic, but the acid content can be diminished. Sugar is a common additive to neutralize acidity, but butter also can help to remove the acid in tomato sauce.
Simmer homemade or store-bought tomato sauce uncovered on a stove top. For sauce made from scratch, allow the ingredients simmer for approximately one hour or until the sauce thickens.
Remove any bay leaves that may be included in homemade sauces. Taste the sauce to see if it is acidic.
Add 1 tbsp. of unsalted butter to round out the flavors. Test the sauce again.
Add 1 tbsp. more of butter if needed. As many as 4 tbsp. can be added to remove the acidity.
Include 1 tsp. sugar or a small amount of baking soda to further aid in the removal of acidity. Add a little bit of sugar or baking soda and try the sauce again.