Food-grade lactic acid is an organic acid that is used as a preservative in food products and as an additive in beverages. It is also used to adjust the pH level in foods and beverages. Lactic acid is a natural preservative and is commonly used to preserve dairy products, such as cheese, yogurt, and sour cream, as well as canned fruits and vegetables. It can be used to produce a tart or sour flavor in foods and beverages and can be used to add a unique flavor to craft beer.