Orange juice has a high acid content. It ranks near the bottom of the pH scale, which ranks the acid content of items on a scale of 0 to 14. Orange juice contains more acid than many other types of juice.
Orange juice is rich with citric acid, a type of acid found in citrus fruits. On the pH scale, which ranges from 0 (most acidic) to 14 (least acidic), orange juice has a pH of 3, between the slightly more acidic lemon juice, with a pH value of 2, and just above the less acidic tomato juice, with a pH value of 4.