pH is useful in many ways in the food industry such as, to produce foods with good qualities, avoid health problems of people ingesting the food, and to keep the product fresh. In order for food to have these qualites, chefs and producers of these materials need to know the appropriate pH of each food, so when the pH goes out of that range, they can discard of it and get a new one. Just a small change in pH can cause the food to spoil. pH can cause changes in flavor, consistancy, and expiration dates.