Coffee The world's primary source of caffeine is the coffee "bean" (the seed of the
coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of
coffee bean and the method of preparation used; even beans within a given bush can show variations in concentration. In general, one serving of coffee ranges from 80 to 100 milligrams, for a single shot (30 milliliters) of arabica-variety
espresso, to approximately 100–125 milligrams for a cup (120 milliliters) of
drip coffee.
Arabica coffee typically contains half the caffeine of the
robusta variety. Tea contains small amounts of
theobromine and slightly higher levels of
theophylline than coffee. Preparation and many other factors have a significant impact on tea, and color is a very poor indicator of caffeine content. Teas like the pale Japanese
green tea,
gyokuro, for example, contain far more caffeine than much darker teas like
lapsang souchong, which has very little. Caffeine is also a common ingredient of
soft drinks, such as
cola, originally prepared from
kola nuts. Soft drinks typically contain 0 to 55 milligrams of caffeine per 12 ounce serving. By contrast,
energy drinks, such as
Red Bull, can start at 80 milligrams of caffeine per serving. The caffeine in these drinks either originates from the ingredients used or is an additive derived from the product of
decaffeination or from chemical synthesis. Guarana, a prime ingredient of energy drinks, contains large amounts of caffeine with small amounts of theobromine and theophylline in a naturally occurring
slow-release excipient.
Other beverages •
Mate is a tea-like drink popular in many parts of South America. Its preparation consists of filling a gourd with the leaves of the South American holly
yerba mate, pouring hot but not boiling water over the leaves, and drinking with a straw, the bombilla, which acts as a filter so as to draw only the liquid and not the yerba leaves. •
Guaraná is a soft drink originating in Brazil made from the seeds of the
Guaraná fruit. • The leaves of
Ilex guayusa, the Ecuadorian holly tree, are placed in boiling water to make a guayusa tea. • The leaves of
Ilex vomitoria, the yaupon holly tree, are placed in boiling water to make a yaupon tea. • Commercially prepared coffee-
flavoured milk beverages are popular in Australia. Examples include
Oak's Ice Coffee and
Farmers Union Iced Coffee. The amount of caffeine in these beverages can vary widely. Caffeine concentrations can differ significantly from the manufacturer's claims. == See also ==