To fully understand the colorful history of this cheese, though, we'll need to take a trip to Cheddar, England, the birthplace of cheddar cheese! But first, let's learn a bit about agricultural science…
Milk contains beta-carotene, the same natural pigment that gives carrots their orange color. Pasture-fed cows produce milk with higher beta-carotene levels in the spring and summer when their diet consists of fresh grass. As a result, their milk produces cheese with a deeper yellow-orange color. Over the winter, when fresh grass isn't available, cows are fed hay, which has less beta-carotene. Less beta-carotene means a paler milk and paler cheese.
Although they may not have understood the science of cheese, people found that yellow cheddar had a better flavor than other white cheeses.
In the 17th century, sneaky cheesemakers realized they could make more money by skimming the cream off and selling it separately. However, the natural yellow-orange pigment is held in the cream, so what was left over was a lower-quality, low-fat white cheese. Cheesemakers found that by adding a bit of dye to their white cheeses, they could trick people into thinking they were getting authentic cheddar cheese. The more yellow the color of the cheese, the higher the price.
Centuries later, we still recognize cheddar cheese as the orange cheese in the dairy aisle. When cheesemakers came to the U.S., they kept the practice of dying cheddar cheese. Why? Perhaps it's best explained as a mix of tradition, marketing (orange cheese stands out among white cheese) and to keep their cheeses uniform in color.
Today, cheddar cheese gets its color from the annatto tree, which grows in tropical regions in Central and South America. Annatto seeds are ground into a red powder and used for coloring foods. Used to dye cheese for more than 200 years, annatto gives cheddar cheese the same color year-round.