Today I found out why mustard is yellow.

A common misconception is that yellow mustard (the kind you put on your hot dog) is yellow because of the mustard seed. This is not true. The mustard seed is a dullish gray, brown color. The striking, bold yellow color actually comes from the rootstock of a plant called turmeric.

Turmeric, native to the rainy humid tropical forests of South Asia, has been used as a natural food dye for centuries. The turmeric plant is harvested annually for its rhizome, or rootstock. The rhizome is boiled, dried out, and ground into a powder. This powder is then mixed with mustard seed powder, vinegar, water, salt, and voila, you got yourself traditional yellow mustard!

Turmeric is also a common ingredient in many South Asian and Indian dishes. It provides an earthy, slightly bitter taste that complements many curries. In addition, it isn’t just the rhizome powder that is used for cooking, but the whole plant. The leaves of the turmeric plant are used in many Indonesian recipes due to the plentifulness of the plant in the region and the sharp flavor of the leaves.

Throughout the generations of living off of the land in the region, people have discovered that turmeric possesses many medicinal qualities. Traditionally, it has been used an anti-inflammatory, antiseptic, and a guard against liver damage. In fact, the American Cancer Society has officially stated that curcumin, the active ingredient in turmeric, is an antioxidant and has shown in preliminary studies to kill cancer cells in lab samples. Plus, it has been found to reduce the growth of several different forms of cancer cells and tumors in lab animals. The United States Institute of Health rated turmeric as “possibly effective” for Osteoarthritis and upset stomach, with research still pending.

Turmeric began to make its way west during the 12th and 13th centuries. In medieval England, turmeric was often called “Indian saffron” since it was often used as a cheaper alternative to the much more pricey saffron. In 1280, Marco Polo wrote in his memoirs that turmeric was a vegetable “with the properties of saffron, though it is not really saffron”. In the 18th century, turmeric was beginning to be grown in Caribbean countries, where the climate was similar to South Asia. Jamaica became a big grower of turmeric and to this day, rhizome powder is still used in Jamaican cuisine.

Getting back to the mustard of it all, mustard itself dates back to the ever-enterprising Romans. They would combine the seeds with unfermented grape juice to create what they called “burning juice”, or mustum ardens in Latin (hence our now familiar English word “mustard”.) The popularity of mustard grew in Rome and swept into their conquered territories. In the Burgundy region of France, most famous for its wines, a little town called Dijon embraced mustard and began making its own variety, substituting the unfermented grape juice with vinegar. To this day, Dijon, France is still known as the mustard capital of the world for its unique and sharp tasting Dijon mustard.

Yellow mustard didn’t come along until the turn of the 20th century. In 1884, two brothers by the name of Robert and George French bought a flourmill in Rochester, New York after their previous flourmill upstate burned down. They named the mill the R.T. French Company. When Robert passed away, George’s other brother, Francis, came aboard to help the family business. In 1904, George began experimenting with “creamy salad mustard”. He added turmeric to the traditional recipe for added presentation and color. Yellow mustard premiered at the St. Louis World’s Fair in 1904 as a condiment to put on hot dogs to great fanfare. The rest, as it were, is mustard history.

If you liked this article and the Bonus Facts below, you might also like:

• Carrots Used to Be Purple Before the 17th Century
• The Color Orange was Named After the Fruit
• Why Garlic Makes Your Breath Smell Bad
• Why Asparagus Makes Your Pee Smell
• Why Milk is White

Bonus Facts:

• During the 15th and 16th centuries, mustard balls became a popular snack in England. Made up of coarse-ground mustard seeds combined with flour and cinnamon, they were moistened, rolled into balls, and dried. The town of Tewkesbury was known for its mustard balls. These treats were even mentioned in William Shakespeare’s play “King Henry the Fourth” Part II.
• Mustard seeds are mentioned in various religious texts. In Judaism, the mustard seed is used to demonstrate the world’s insignificance (as compared the universe and heavens). In Christianity, the Bible uses mustard seeds in a few of its parables (stories meant to teach lessons). In Matthew 13:31, 32, it reads, “He set another parable before them, saying, ‘The Kingdom of Heaven is like a grain of mustard seed, which a man took, and sowed in his field; which indeed is smaller than all seeds. But when it is grown, it is greater than the herbs, and becomes a tree, so that the birds of the air come and lodge in its branches.'” This is often interpreted to mean that mustard seeds represent the immense growth of God’s church, from tiny beginnings to an enormous scale.  However, due to the Principle of Expositional Constancy, which basically just means symbols in one parable have the same meanings across, we come away with a much darker meaning to the parable, which is the true meaning according to many theologians, but the opposite of what most laypeople think when reading it.  The mustard plant should not grow into a tree, but rather more of a bush.  The fact that this seed grows into a tree, showing abnormal growth, is then a bad thing (abnormal in parables = bad).  Further “birds of the air” always refers to Satan and his minions.  So essentially, this parable is actually saying that the Church would start out OK, then gradually be perverted from what it was meant to be with many who are actually evil becoming prominent members of the Church.  This same idea about the Church’s growth and what it would become is in other parables and backed up by other scriptures, which again is why many theologians today feel the parable of the mustard seed should be interpreted this way- more of a warning, rather than speaking of the incredible growth of the Church specifically.
• Grey-Poupon, the world’s most famous Dijon mustard, was created in 1777 by a partnership between Maurice Grey, a mustard maker with an unusual recipe calling for white wine, and Auguste Poupon, his financial backer. Grey-Poupon took off, not just because of the uniqueness of the recipe, but also because they were the first mustard makers to utilize the automatic mustard-making machine. Their original store still stands in downtown Dijon today.
• It has long been rumored that Ben Franklin was the first person to bring mustard to America when he arrived back from France in 1785 after serving as the Ambassador. Likely, this is nothing more than an urban myth.