Caramel color is made by heating sugars or other carbohydrates at high temperatures in a controlled process called caramelization. The starting sugars are typically derived from corn, though wheat, beet sugar, cane sugar, and other carbohydrate sources can also be used. Depending on which chemical reactants are added during heating, the result falls into one of four distinct classes, each with different properties suited to different foods and drinks.
The Base Ingredients
At its core, caramel color starts with simple carbohydrates. Corn-derived sugars (like dextrose or high-fructose corn syrup) are the most common starting material in the United States. The sugar is heated under carefully controlled conditions, and acids, bases, or salts may be added to speed up the browning reaction. What makes the four classes of caramel color different from one another is which additional compounds are introduced during this heating process.
The Four Classes of Caramel Color
Food regulators worldwide recognize four classes, labeled I through IV. Each uses different reactants during production, which changes the color intensity, electrical charge, and stability of the final product.
Class I (Plain Caramel): The simplest version. Sugars are heated with acids, bases, or salts, but no ammonium or sulfite compounds are used. This produces a lighter color commonly found in whiskeys, liqueurs, sauces, juice concentrates, and poultry coatings.
Class II (Caustic Sulfite Caramel): Sugars are heated in the presence of sulfite compounds. No ammonium compounds are involved. Class II caramel colors appear in wines, rum, brandy, light cake mixes, and certain snack foods.
Class III (Ammonia Caramel): Sugars are heated with ammonium compounds such as ammonium hydroxide or ammonium carbonate. This class is widely used in beer, cereal, pet food, soy sauce, BBQ sauce, and gravy.
Class IV (Ammonium Sulfite Caramel): Sugars are heated with both sulfite and ammonium compounds. This produces the darkest, most intense color and is the type most people encounter daily. It’s the caramel color in cola and other soft drinks, balsamic vinegar, coffee products, chocolate syrups, baked goods, soups, and seasoning blends.
Why Different Classes Exist
The chemistry behind each class isn’t just about color intensity. Caramel color forms a colloid when dissolved in water, meaning the tiny particles carry an electrical charge. Whether that charge is positive or negative depends on the acidity of the liquid it’s mixed into. For a product like cola, which is highly acidic, the caramel color needs to carry a strong negative charge to stay dissolved and not form ugly sediment at the bottom of the bottle. Class IV caramel is specifically engineered for this, with a very low isoelectric point (the pH at which the particles have no charge) so it remains stable in acidic drinks.
Caramel color mixes with water in any proportion and dissolves in alcohol solutions up to about 55% by volume, which is why it works well in both soft drinks and spirits. It won’t dissolve in oils or organic solvents, so you won’t find it used in oil-based products.
The 4-MEI Concern
When ammonium compounds are used during production (Classes III and IV), a byproduct called 4-methylimidazole, or 4-MEI, can form. This happens through a reaction between sugars and the nitrogen in ammonium compounds, a process related to the same Maillard reaction that browns bread crusts and seared meat.
California added 4-MEI to its Proposition 65 list, meaning products sold in the state that expose consumers to significant amounts must carry a warning label. The state’s Office of Environmental Health Hazard Assessment established a “safe harbor” level: products exposing people to amounts below that threshold don’t require a warning. After California’s listing, several major beverage companies reformulated their caramel color to reduce 4-MEI levels, so many colas and dark sodas now contain significantly less than they did a decade ago.
The FDA considers caramel color safe at the levels found in food. It is permanently listed as an approved color additive, exempt from the batch-by-batch certification required for many synthetic dyes. It’s approved for use in foods, drugs, and cosmetics, including products applied around the eyes.
Is Caramel Color Gluten-Free?
Yes. Even when caramel color is derived from wheat or barley starch, the high-heat manufacturing process breaks down and removes gluten proteins. The final product does not contain measurable gluten. In practice, most caramel color produced in the U.S. is made from corn, making this a non-issue for the vast majority of products on store shelves.
Where You’ll Find It
Caramel color is one of the most widely used food colorings in the world. If a packaged food or drink has a brown hue, there’s a good chance caramel color is responsible. Soft drinks, especially colas, are the single largest application. But it also shows up in places you might not expect: soy sauce, balsamic vinegar, pre-made gravies, dark breads, pet food, seasoning blends, and even some beers and whiskeys owe their characteristic brown tones partly or entirely to added caramel color rather than the natural color of their ingredients.
On ingredient labels, you’ll typically just see “caramel color” without a class designation. In international markets, look for E150a through E150d, which correspond to Classes I through IV respectively.