Coffee is a beverage prepared from roasted coffee beans. Darkly colored,
bitter, and slightly acidic, coffee has a stimulating effect on humans,
primarily due to its caffeine content. It has the highest sales in the
world market for hot drinks.
The seeds of the Coffea plant's fruits are
separated to produce unroasted green coffee beans. The beans are roasted
and then ground into fine particles that are typically steeped in hot
water before being filtered out, producing a cup of coffee. It is usually
served hot, although chilled or iced coffee is common. Coffee can be
prepared and presented in a variety of ways (e.g., espresso, French press,
caffè latte, or already-brewed canned coffee). Sugar, sugar substitutes,
milk, and cream are often added to mask the bitter taste or enhance the
flavor.
Coffee contains caffeine, a stimulant that has been shown to
increase energy levels and decrease fatigue by altering levels of certain neurotransmitters in the brain.