The color and appearance of tea are important factors in determining its quality. Tea can be almost any color, ranging from a pale green or yellow to a deep red or even blue. The more intense the color, however, does not always imply that you are drinking the highest quality tea. Color adulterants are, in fact, more common than you might think. Have you been consuming tainted tea?

What factors influence color?

The color of the tea is determined by a variety of factors. Water temperature, leaf quality, steeping time, leaf size, and water quality all have an impact on the color of the brew. Tea leaf color is determined by the tea varietal, growing conditions, manufacturing process, chemical composition, and other factors. It's not always easy to tell if the color of your tea is due to a variety of factors.

Tea colors that are naturally occurring

Tea color naturally ranges from nearly transparent (as in Silver Needle) to orange and red for black teas. Blends typically contain more color. Any blend containing hibiscus, for example, will be a deep purple color. Even if the tea is not tainted, tea in teabags will have a more intense color. For example, chlorophyll gives the tea its intense green color, so teas that contain more chlorophyll will naturally have a greener color.

Tea that has been tampered with

Tea adulteration is not a new issue. Bismark Brown, Prussian Blue, coal tar dye, indigo, soapstone, plumbago (graphite), and gypsum are common coloring adulterants found in tea. However, it is not only the color that has been "enhanced." Tea leaves can also be tampered with to make them appear more appealing, command a higher price, weigh more, or even conceal the fact that they have already been used. Tea has also been found to contain starch, sand, China clay, French chalk, iron fillings, chicory, lather flakes, caffeine, used tea leaves, and other impurities.

How can you tell if a cup of tea is bad?

Detecting adulterated tea is not always easy, and in some cases, it is impossible. The simplest, but not the only, method would be to immerse a few tea leaves in cold water and observe whether the color changed immediately. Tea, in general, requires a specific temperature and time to release its compounds, which provide flavor, color, and health benefits. Some colors can be detected using a microscope, while others can be detected using other chemical methods. According to the Indian Tea Board, black tea typically contains plumbago, which is used in lead pencils and can be detected using a microscope.

Why should you avoid adulterated tea?

Adulterants in tea can be harmful. While some adulterants, such as turmeric, are likely to be safe, others have the potential to cause cancer. In India, “several cases of liver infection have been reported across the country as a result of consuming adulterated tea.” Besides, you want to get what you pay for, not a lower-quality tea. With adulterated tea, it's not just the fake color that's a problem. Many natural teas and blends contain harmful pesticides, metals such as copper, iron, or lead, harmful chemicals, and sugar.