What Is Citric Acid?

Buying, Cooking, and Recipes

Bottles of grapefruit and oranges juice with whole fruit on a table

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Citric acid is one of the most common food preservatives and flavoring additives. It can be found naturally in citrus fruits but is also manufactured. Its name is derived from the fact that it's an organic acid found in many fruits and vegetables, especially citrus fruits. Citric acid is a concentrated powder that is prized for its sour flavor, preservative quality, and ability to act as a pH buffer. For these reasons, citric acid is found on the ingredients list of many foods in your kitchen pantry, including preserves, candy, and crunchy snacks. It is also known as "sour salt" due to its flavor and similar appearance and texture to salt.

Fast Facts

  • Also Known As: Sour salt
  • Shelf Life: 3 years opened; 5 years unopened
  • Used As: Flavor enhancer and preservative
  • Taste: Sour

What Is Citric Acid?

In 1917, American food chemist James Currie discovered that the mold Aspergillus niger could produce citric acid as a byproduct of metabolizing sucrose or glucose, which has proved more efficient and less expensive than extracting from citrus fruits. Although citric acid is found in high concentrations in many citrus fruits like lemons, it is not economical to extract the acid from fruit for industrial use. Plus, the demand for citric acid far outweighs the supply of citrus fruit available. Thus, once it was possible to produce a seemingly endless supply of citric acid, companies like Pfizer and Citrique Belge began manufacturing it on an industrial scale.

Citric Acid Uses

Citric acid has many uses in food production. It is a flavor enhancer, preservative, and helps facilitate the ripening process. About 50 percent of the world’s citric acid production is used as a flavor booster in beverages, and because citric acid is made in a powder form, it's added to dry foods such as seasoning salts, flavoring powders, and crunchy snacks when a sour flavor is desired.

The acidic pH of citric acid makes it useful as a food preservative and preserves the color of the food since it significantly slows the oxidation. Since many bacteria are unable to grow in an acidic environment, citric acid is often added to jams, jellies, candy, canned foods, and even meat products as a form of preservation. Citric acid is also used to facilitate the ripening process when making cheese, particularly mozzarella. It is employed to adjust the pH of solutions when brewing both beer and wine, and works to keep fats from separating in homemade ice cream; it also prevents sugar from crystallizing in caramels. A small pinch of citric acid can also enhance the leavening power of baking soda, making it an ideal secret ingredient for cakes and biscuits. Those on a low-sodium diet may sub in citric acid for salt when seasoning.

How to Cook With Citric Acid

Citric acid can be measured and added to recipes either as an ingredient or as a replacement for other acids like lemon juice or vinegar. For example, when canning tomatoes, a 1/2 teaspoon of powdered citric acid can be used for every quart of tomatoes. The citric acid powder can also be sprinkled over finished recipes such as guacamole or raw fruit such as apples, to maintain color.

If making cheese like ricotta or paneer, citric acid will guarantee a perfect balance of acidity without adding any additional flavors. Dissolve a 1/2 teaspoon citric acid in 2 tablespoons of water and use in place of 2 tablespoons lemon juice or vinegar.

Citric acid can be used in place of salt in sour bread recipes like sourdough and rye. Most often, no more than 1 tablespoon of citric acid will be needed. It can also be used when preparing game meat to help eliminate any bacteria: Spray a solution of 1 ounce citric acid with 1 quart water prior to cooking.

Be mindful that the acid is an irritant to the eyes as well as the skin with prolonged exposure, so take caution when using.

What Does It Taste Like?

Citric acid adds a sour taste to dishes and has a slightly tart, refreshing flavor, which balances the sweetness in sodas, teas, juices, and other drinks.

Citric Acid Recipes

Unless making your own cheese, it may be hard to come by a variety of recipes calling for citric acid. But those that include vinegar or lemon juice on the ingredient list—like certain soups and pickled foods—are good candidates for using the sour powdered substance.

Where to Buy Citric Acid

Citric acid can be bought in powder form and is usually available in stores with other home canning supplies, as well as in natural food stores or health food stores along with other vitamins and dietary supplements. In some grocery stores, citric acid is sold in small shakers and labeled as "sour salt." It is also often found at Indian food markets as it is used to make paneer. Citric acid is packaged in pouches, tubs, and canisters, and is available in bulk.

Storage

Store citric acid in its original container in a cool, dry place. From the date of manufacturing, it has a shelf life of three years once opened and will stay stable for at least five years unopened.

Nutrition and Benefits

Citric acid has zero calories and fat but also no other nutritive values. While consuming natural citric acid from fruits and vegetables has health benefits—it helps metabolize energy and may protect against kidney stones—ingesting the manufactured version hasn't been proven beneficial to our health.