All true tea comes from a single plant species, Camellia sinensis. The six classic types are white, green, yellow, oolong, black, and pu-erh. What makes them different isn’t the plant itself but what happens after the leaves are picked: how much they’re dried, heated, rolled, and exposed to oxygen. Beyond these six, the word “tea” is also used casually for herbal infusions made from entirely different plants.
One Plant, Six Teas
The key variable separating tea types is oxidation, the same chemical reaction that turns a sliced apple brown. When tea leaves are bruised or crushed, enzymes inside react with oxygen in the air, darkening the leaf and changing its flavor. Tea makers control this process precisely, stopping oxidation early for lighter teas and letting it run fully for darker ones. That single spectrum of oxidation, from near-zero to complete, produces a remarkable range of color, taste, and chemical makeup.
White Tea
White tea is the least processed of all teas. Producers pick young buds and tender leaves, then lay them out to dry in the sun with minimal handling. Oxidation stays around 0 to 5%, preserving much of the leaf’s original chemistry. The result is a pale, delicate brew with soft floral or honey-like notes.
That minimal processing pays off nutritionally. A comparative study of silver needle white tea, green tea, and black tea found that white tea had the highest total phenolic content at 133 milligrams per gram, compared to 118 for green and 102 for black. These phenolic compounds act as antioxidants, and the unopened buds used for white tea appear to concentrate them more than mature leaves do.
Green Tea
Green tea is the largest tea family in the world. Right after harvest, the leaves are heated to deactivate the enzymes that cause oxidation, keeping levels between roughly 5 and 10%. There are two main methods: the Japanese approach uses steam, producing a bright, grassy flavor, while the Chinese method pan-roasts the leaves, yielding a nuttier, toasted character.
Green tea is especially rich in a group of antioxidant compounds called catechins. The most abundant of these accounts for roughly 50% of green tea’s total polyphenol content and has been studied extensively for its anti-inflammatory, heart-protective, and metabolic effects. Green tea also leads all tea types in L-theanine, an amino acid that promotes calm focus by boosting levels of several mood-regulating brain chemicals, including serotonin and dopamine. Green tea averages 6.56 milligrams of L-theanine per gram of dry leaf, slightly more than white (6.26), oolong (6.09), or black tea (5.13).
Yellow Tea
Yellow tea is one of the rarest and least known varieties. The process starts similarly to green tea, but with a lower roasting temperature. After that initial heating, the leaves are wrapped in cloth and left to rest in a step sometimes called “smothering.” This sealed resting period allows a gentle, oxygen-free transformation that softens the grassy edge of green tea and produces a smoother, slightly sweet cup. Because it’s labor-intensive and produced in small quantities, yellow tea can be difficult to find outside specialty shops.
Oolong Tea
Oolong sits in the wide middle ground between green and black tea, with oxidation levels ranging from 20% to 80%. After harvest, the leaves are shaken on large trays to bruise the edges and start oxidation, then heat is applied at just the right moment to stop it. The leaves are then rolled, giving them a fuller body.
This range means oolongs can taste dramatically different from one another. A lightly oxidized oolong might remind you of a floral green tea, while a heavily oxidized one can approach the richness of black tea. Taiwanese high-mountain oolongs tend toward the lighter end, while traditional Chinese Wuyi rock oolongs are roasted and dark.
Black Tea
Black tea is fully oxidized, typically 80 to 100%. After withering, the leaves are crushed to open their cell structure, triggering rapid and complete oxidation. The leaves darken to deep brown or black and develop bold, malty, or tannic flavors. They’re then dried and sorted by leaf size.
The oxidation process creates compounds called theaflavins, which give black tea its reddish-amber color and distinct taste. These compounds have been studied for their ability to lower cholesterol absorption in the gut by interfering with the way dietary cholesterol is packaged for absorption. Research in the Journal of Agricultural and Food Chemistry found a dose-dependent effect: the more theaflavins present, the less cholesterol was incorporated into the tiny particles that carry it into the bloodstream. Additional oxidation products called thearubigins make up 10 to 20% of black tea’s dry weight and contribute to its full body, though they’re less well understood.
Black tea also delivers the most caffeine of the common varieties. An 8-ounce cup of brewed black tea contains about 48 milligrams of caffeine, compared to roughly 29 milligrams for green tea.
Pu-erh (Dark Tea)
Pu-erh is unique because it undergoes microbial fermentation, not just oxidation. The leaves are piled up, moistened, covered, and turned regularly while microorganisms transform their chemistry over weeks, months, or even years. This is the same basic principle behind foods like yogurt or aged cheese, applied to tea.
There are two styles. Traditional pu-erh, called “raw” or sheng, is pressed into cakes and left to ferment naturally over years or decades, developing complex earthy, woody flavors that change with age. The modern “ripe” or shou method accelerates fermentation using controlled moisture and heat, producing a similar depth of flavor in a matter of weeks. Well-aged raw pu-erh is highly collectible, with some vintage cakes selling for thousands of dollars.
Herbal Teas Are Not Technically Tea
Chamomile, peppermint, rooibos, hibiscus, ginger: these are all commonly called “tea,” but they contain no Camellia sinensis at all. The proper term is “tisane,” an infusion made from herbs, flowers, spices, berries, or bark. Because they come from entirely different plants, tisanes have their own distinct chemical profiles and are naturally caffeine-free (with a few exceptions like yerba mate and guayusa, which come from caffeinated plants unrelated to tea).
The distinction matters if you’re interested in the specific compounds found in true tea, like L-theanine, catechins, or theaflavins. Herbal infusions have their own beneficial compounds, but they’re fundamentally different beverages from a botanical standpoint.
Brewing Temperatures and Times
Using the wrong water temperature is the most common way to ruin a cup of tea. Delicate teas need cooler water, while darker, more oxidized teas can handle a full boil.
- White tea: 175 to 180°F, steep 1 to 2 minutes
- Yellow tea: 167 to 176°F, steep 2 minutes
- Green tea: 175 to 180°F, steep 2 minutes
- Oolong tea: 195°F, steep 2 to 3 minutes
- Black tea: 212°F (full boil), steep 3 to 5 minutes
- Pu-erh tea: 212°F, steep 2 to 3 minutes
- Herbal tea: 212°F, steep 3 to 4 minutes
Pouring boiling water over green or white tea scalds the leaves and releases bitter compounds, producing a harsh cup that doesn’t reflect what the tea actually tastes like. If you don’t have a temperature-controlled kettle, letting boiled water sit for two to three minutes will bring it down to roughly the right range for green and white teas.