Whether you love mouth-puckering sourness or prefer a slightly sour sensation, the intense flavor of sour candy comes from organic acids. While there are at least eight different acids used in sour candy, the four most common are citric, malic, tartaric and fumaric acids. Each acid has a different level of sourness, as well as other flavor nuances of bitterness and astringency. Sour candies usually contain a mixture of two or more acids to create the desired flavor.
Citric acid provides a burst of tartness. It comes from lemons, grapefruit and other citrus fruits, which makes it easy to imagine the sour tang it delivers. Berries also contain citric acid, and it's a secondary acid in many fruits and vegetables.
Food-grade citric acid is commercially produced by fermenting sugar with microorganisms. In addition to contributing sour flavor, it prevents spoilage and stabilizes color in foods and beverages.
Beyond its use in candy, citric acid fills beneficial roles in your body. It works as an antioxidant, and it’s essential for energy production. Citric acid is also used to help prevent kidney stones.
Malic acid delivers a smooth, mellow tartness similar to biting into an apple, where it's the predominant acid. Apricots, cherries and tomatoes also contain malic acid. In candy, it boosts the intensity of sour flavors and enhances fruit flavors, reports food-grade chemical supplier Bartek.
Like citric acid, malic acid is produced in your body, participates in the synthesis of energy and can be commercially produced through fermentation. A small study published in the Journal of Endourology in February 2014 reported that malic acid may help with calcium oxalate kidney stones.
Fumaric and Tartaric Acids
Fumaric acid is the strongest and most sour-tasting acid of the organic acids. In candy, it creates a long-lasting sour flavor because it doesn’t dissolve as easily as other acids. A small amount of fumaric acid naturally occurs in apples, beans, carrots and tomatoes.
Tartaric acid tastes moderately sour and is more astringent than citric and malic acids. While it's often found in sour candies, tartaric acid is also an essential ingredient in cream of tartar and baking powder. This organic acid is associated with grapes and wine, as well as bananas and tamarinds.
While the amount of acid you’ll get from occasionally enjoying sour candy isn’t likely to cause problems, organic acids can temporarily irritate your tongue and mouth, especially if you eat multiple pieces in a short time.
On the pH scale, which measures acidity and assigns a value of zero as the most acidic, sour candies have a pH between 2 and 3. This makes them acidic enough to erode tooth enamel, reports the Minnesota Dental Association.
You can reduce damage from acids by limiting the amount of time you have sour candy in your mouth and rinsing with water as soon as you’re finished. Don’t brush your teeth for at least an hour, or you’ll exacerbate the acid’s damage.