The mildly bitter taste of caffeine is part of the complex flavor of some beverages.
Caffeine is a naturally occurring ingredient found in dozens of plants, beans, and seeds. In the U.S., coffee is the most popular source of caffeine; other common sources include tea, chocolate, energy drinks and some soft drinks.
The amount of caffeine in food and beverage products varies with serving size, type of product and method of preparation. An 8 fluid ounce (240 ml) serving of Coca-Cola has 23 milligrams of caffeine, which is about one-third the amount of caffeine found in a cup of brewed coffee and one-half the amount found in a cup of tea. The caffeine content of most energy drinks is similar to that of coffee.
Manufacturers are required to list caffeine in the ingredients list if it has been added to the food or beverage. In some countries, depending on regulations, The Coca-Cola Company also voluntarily displays the caffeine content of its beverages on the product label.