All true teas come from the Camellia sinensis plant. The primary caffeinated types—black, oolong, and green—result from differences in the manufacturing process. Herbal teas, or tisanes, contain no true tea leaves but come from the flowers, berries, peels, seeds, leaves, and roots of many different plants.

Black. English Breakfast, the most popular of all teas, is a blend of fine black teas from India, Ceylon, and China. When blended with milk, English Breakfast creates a bouquet reminiscent of hot toast, which may account for its name. Earl Grey (named for a former prime minister of England) is the second-most popular tea in the world, smoky with a hint of sweetness. Usually made by blending black teas and bergamot oil, Earl Grey is best served plain.

Green. Made from tea leaves steamed immediately after being picked, it has a mild aroma and a natural, delicate taste. Green tea contains potent antioxidants, including catechins, recently the focus of widespread study for anticancer potential. Green tea contains about three times the quantity of catechins found in black tea.

White. Considered among the rarest types of tea available, made from the delicate and unfermented blossoms and infant shoots of the tea plant. White tea is harvested in the spring, when fine white hairs cover the leaves. The low-caffeine brew is clear and almost colorless. Some research indicates that white teas have even more antioxidant health benefits than green teas.

Red. Called rooibos (pronounced roy boss), this herbal variety grows in the Cederberg mountain range of South Africa, where residents have used it for centuries to calm nerves, soothe upset stomachs, prevent sleepless nights, and settle colicky babies. It has a full, naturally sweet flavor and is rich in antioxidants.

—L.E.