Tea and Caffeine
By: Ric Rhinehart
Fresh Cup Magazine
Tea leaves typically contain from 3-5 percent caffeine by dry weight. This is irrelevant, however, because no one sits down and eats a bowl of dry tea leaves. If a person did, he or she would intake a massive amount of caffeine - nearly 15,000 mg. for each pound consumed. The real question is how much caffeine does a cup of tea contain?
Once again, the answer is somewhat complicated. Caffeine is a water-soluble molecule. The amount of caffeine that dissolves into the water depends on the amount of dry tea used to brew a cup. If a person uses the traditional two grams of tea per 5.5 ounces of water, the potential caffeine content for a cup of tea ranges from 60-100 mg.
Still not confused? Consider this - the amount of caffeine present in the cup also depends on the steeping time, leaf size and the temperature of the water. For example, people steep some green teas for very short periods of time and with relatively cool water (compared to the near boiling water used to extract black tea flavors). Therefore these green teas seemingly have less caffeine because they're in contact less with the water, although the tea by dry weight may contain the same amount of caffeine. This is one reason for the general misconception that green tea always contains less caffeine than black or oolong tea.
Here's more fuel for the fires of confusion. The caffeine content in dry tea leaves is affected by a variety of factors, including processing methodology (especially firing), altitude, soil chemistry, growth rate, clonal selection, and the maturity of the leaf at plucking. Generally speaking, teas that grow more slowly, such as those grown under shade or at high altitudes, synthesize more caffeine.
Certain trace minerals present in the soil also can affect the caffeine content. Soil with greater zinc content, for example, produces tea leaves with more caffeine. Young leaves and buds-the ideal ingredients for good quality tea-contain greater concentrations of caffeine than older leaves and stalks. Thus, a high-grown, shaded green tea grown in zinc-rich soil and plucked only for the top leaves and buds can produce a cup of tea with twice as much caffeine as a poor quality, over-fired, low-grown black tea.
Ultimately, the only way to truly determine caffeine content is to test the teas yourself, brewed with your preferred method If you are exceptionally sensitive to caffeine, try decaffeinated tea. If you are an average consumer, practice common sense and drink tea in moderation.
TEA STATISTICS
There were 6,671,818 acres (2,700,000 hectares) planted to tea worldwide in 1996.
Those tea plantations produced 2.7 billion kg. (5.9 billion lb.) of tea worldwide in 1996.
People consumed nearly 1.3 trillion cups of tea worldwide in 1996 (based on a 2-gram average cup; the world population in 1996 was 5,766,000,000).
In 1994, U.s. citizens consumed about 50 billion six ounce servings of tea, or 2.25 billion gallons. Black tea accounted for 94 percent, green-tea for 4 percent, oolong for 1 percent, and flavored for 1 percent. Away-from-home tea consumption increased by more than 12 percent in 1994.
On a daily basis, about half of the American population drinks tea, totaling more than 125 million cups or glasses per day. Americans drink 85 percent of their tea on ice.