"Why is cheddar cheese orange?"

"Cheddar cheese is naturally off-white to pale yellow. The orange color has nothing to do with the milk or the cheese-making process. Historically, higher-quality milk from grass-fed cows contained more beta-carotene, producing a slightly more yellow cheese. Cheese makers began adding annatto to standardize color, and eventually the orange color became the expected appearance of cheddar regardless of milk source."

"What is the difference between bixin and norbixin?"

"Bixin is the fat-soluble form of the annatto carotenoid, found in the seed coat. Norbixin is the water-soluble form produced by saponification (hydrolysis with alkali) of bixin. Food manufacturers use oil-soluble annatto (bixin-based) for fatty products and water-soluble annatto (norbixin-based) for water-based products and cheeses. Both are yellow-orange pigments."

"Is annatto classified the same as artificial food dyes?"

"No. Annatto is classified as a color additive exempt from certification under 21 CFR Part 73. Synthetic food dyes like Red 40 and Yellow 5 require batch certification by the FDA. The natural vs. synthetic distinction is the reason for the different classification. Neither category is inherently safer than the other."

"Does annatto affect flavor?"

"At concentrations used for coloring, annatto has minimal flavor impact. At higher concentrations, it can contribute a faint earthy, peppery note. Traditional users of annatto in Latin American and Caribbean cuisines (where it's used in achiote paste and adobo) use it both for color and for a subtle flavor contribution that's more detectable at culinary rather than food-additive concentrations."

"Which foods are most likely to contain annatto?"

"Cheddar and American cheese are the most common sources in the American diet. It also appears in butter, margarine, some orange juice products, sausage casings, snack foods, and breakfast cereals. People with annatto sensitivity should check dairy product labels specifically."

Annatto: The Natural Orange Color in Cheese and Butter

Quick Answer

Annatto is a natural yellow-orange food coloring derived from Bixa orellana seeds. It colors cheddar cheese, butter, margarine, and many dairy products. The FDA classifies it as a natural color not subject to certification requirements. Allergic reactions are rare but occur more frequently with annatto than with most natural colors.

The Science

White cheddar and orange cheddar taste the same. They’re made from the same milk through the same process. The color difference comes entirely from annatto, a natural dye extracted from seeds of the Bixa orellana plant.

The story of why cheddar is orange is more interesting than you might expect.

Where Annatto Comes From

Bixa orellana is a tropical shrub native to South America, now cultivated throughout Latin America, the Caribbean, and parts of Africa and Asia. The plant produces spiny red seed pods containing seeds coated in a bright reddish-orange pulp. That pigmented coating is the source of annatto.

Traditional cultures across the Americas have used annatto for thousands of years, both as a food colorant and as body paint (which is why Bixa orellana is sometimes called “lipstick tree”). In contemporary cuisine, it forms the base of achiote paste, a fundamental flavoring in Yucatecan, Cuban, and Puerto Rican cooking.

The two key pigment compounds are bixin (fat-soluble, found in the seed coat) and norbixin (water-soluble, derived from bixin through a saponification step). Commercial annatto extracts come in both oil-soluble and water-soluble versions to match different food manufacturing needs.

The Orange Cheddar History

Before refrigeration, cheese quality varied significantly by season. Milk from cows grazing on fresh grass in summer contained more beta-carotene, which made the milk fat (and the resulting cheese) slightly more yellow. Consumers came to associate the deeper yellow color with higher fat content and richer flavor.

As cheese making industrialized, producers began adding annatto to standardize color regardless of season, feed, or milk source. Over generations, the orange-yellow cheddar became the expected default. White cheddar looks like the unusual variety now precisely because the norm was inverted.

The orange color in your cheddar has nothing to do with flavor, quality, or nutritional content. It’s a historical artifact that became a visual standard.

How the Coloring Works

Bixin and norbixin are carotenoid compounds. The carotenoid family includes beta-carotene, lycopene, and lutein, pigments found throughout the plant kingdom. They absorb blue-violet light and reflect yellow-orange wavelengths, producing the characteristic color.

In cheese production, the annatto is added to the milk before coagulation. It distributes through the milk fat. When the curd forms and excess moisture is expelled as whey, the bixin concentrates in the curd. The resulting cheese is consistently colored.

In butter and margarine, liquid annatto extract is mixed in during the churning or blending process.

Regulatory Status

The FDA classifies annatto as a color additive exempt from certification, listed at 21 CFR 73.30. “Exempt from certification” means the FDA doesn’t test each batch the way it does with synthetic dyes. Instead, the manufacturer is responsible for the product meeting the relevant specifications.

EFSA completed a re-evaluation of annatto in 2016 and established an ADI of 0.065 mg per kilogram of body weight per day for norbixin-based (water-soluble) extracts. For bixin-based (fat-soluble) extracts, the ADI was set at 6 mg/kg/day. The difference reflects different bioavailability.

The Allergy Question

Annatto has a more documented allergic profile than most natural food colors. Case reports in the literature go back to the 1970s. Reactions range from urticaria (hives) and angioedema to, in rare cases, anaphylaxis.

The allergy mechanism appears to involve IgE-mediated responses to annatto proteins or compounds, though the exact allergen hasn’t been fully characterized. Importantly, annatto is not in the same regulatory category as the major food allergens (tree nuts, peanuts, shellfish, etc.), so it doesn’t require the same bold labeling.

For context, “more than most natural colors” doesn’t mean “common.” Annatto allergy is still rare in the general population. But it’s worth knowing about if you have unexplained reactions to dairy products or other colored foods.

If you suspect an annatto sensitivity, dairy products (especially cheese) and processed snack foods are the most common exposure sources in the US diet.

What This Means for You

Annatto is safe for the vast majority of people and is one of the most widely used natural food colors. If you have a history of unexplained food reactions and you eat a lot of colored dairy products, annatto is worth knowing about as a potential (if uncommon) trigger. For most consumers, it's a non-issue.