Is There Caffeine in Tea? Levels by Type

All tea made from the Camellia sinensis plant contains caffeine, with a single cup typically delivering somewhere between 14 and 61 milligrams depending on the type, the particular leaves, and how you brew it. That range is wide enough to matter: the low end is barely more than a piece of chocolate, while the high end approaches the caffeine in a weak cup of coffee. The reason the numbers are so hard to pin down has less to do with whether you picked green or black and more to do with a collection of variables that most people never think about.

Where Tea’s Caffeine Comes From

Caffeine is not something added during processing or a byproduct of fermentation. The tea plant produces it naturally as a defense chemical. Research has shown that caffeine accumulates in tea leaves primarily to protect against fungal pathogens, functioning as a kind of built-in pesticide for the plant.¹ This means every part of the tea plant that gets harvested for drinking already has caffeine baked in, from buds down to mature leaves. The concentration is not uniform across the plant, though. Younger leaves and buds tend to have more caffeine than older, more mature leaves, because the plant invests more defensive chemistry in its newest growth.² This fact alone scrambles some common assumptions about which types of tea are “low caffeine.”

Black Tea

Black tea is the most widely consumed variety in much of the Western world, and its caffeine content is frequently cited as the highest among teas. One well-known analysis found that a cup of black tea averages about 28 to 46 milligrams of caffeine, considerably less than a cup of brewed coffee at roughly 107 to 151 milligrams.³ When measured by dry weight rather than per cup, black teas have shown caffeine levels in the range of 22 to 28 milligrams per gram of dry leaf, significantly higher than green teas at 11 to 20 milligrams per gram.⁴

That said, per-cup numbers bounce around quite a bit. A study that measured caffeine across white, green, and black teas found concentrations ranging from 14 to 61 milligrams per serving, with “no observable trend in caffeine concentration due to the variety of tea.”⁵ In other words, a particular green tea brewed a certain way could easily outpace a particular black tea. The idea that black tea is always the caffeine leader is a useful approximation, not a rule.

Green Tea

Green tea tends to land lower on caffeine per cup than black tea, mostly because the leaves are processed less and are often brewed at lower temperatures for shorter times. But the raw leaf material is not always lower in caffeine. When you measure dry leaves before any brewing happens, the gap between black and green narrows or sometimes disappears entirely, depending on the cultivar and harvest. A green tea made from young buds plucked in spring could have more caffeine in the leaf than an autumn-harvest black tea from older leaves.

Shade-grown green teas like matcha and gyokuro deserve special mention. When tea plants are shaded before harvest, they ramp up production of certain compounds including caffeine.² And since matcha involves grinding the whole leaf into a powder and consuming it entirely rather than steeping and discarding, you get all the caffeine in the leaf rather than just what dissolves into water. A bowl of matcha can easily reach 60 to 70 milligrams of caffeine, putting it in the same ballpark as a shot of espresso.

White Tea

White tea has a persistent reputation as the gentlest option, the one you pick when you want minimal caffeine. This is one of the more stubborn myths in the tea world. White tea is typically made from very young buds and the newest leaves of the plant, and as noted earlier, younger plant material tends to carry higher caffeine concentrations.² The same study that found no observable caffeine trend across tea types included white teas in its 14-to-61-milligram-per-serving range.⁵

Why the misconception? Probably because white tea tastes delicate and is marketed as minimally processed. People associate light flavor with low caffeine, but those are separate properties. Processing affects flavor compounds, oxidation levels, and color far more than it affects the amount of caffeine already present in the leaf. If you are choosing white tea specifically to avoid caffeine, you may not be getting the benefit you expect.

Oolong and Pu-erh

Oolong sits between green and black tea in terms of oxidation, so its caffeine content generally falls in that middle range too, roughly 16 to 55 milligrams per cup depending on the specific oolong and how it is brewed. Highly roasted oolongs tend to feel less stimulating, though some of that perception is about the L-theanine and other compounds modulating how you experience the caffeine rather than the caffeine actually being lower.

Pu-erh tea is a different case. Pu-erh undergoes microbial fermentation after initial processing, and what happens to caffeine during that step is genuinely interesting. Some of the fungi involved in pu-erh fermentation convert caffeine into theophylline, a related compound. One study found that a particular fungal strain degraded about 29 milligrams per gram of caffeine, converting over 93% of it into theophylline.⁶ However, the overall picture is more complicated: most research on pu-erh fermentation has found that caffeine content actually tends to increase during the post-fermentation process, possibly because the breakdown of other leaf components concentrates remaining caffeine.⁷ So despite the fermentation, a cup of aged pu-erh is not reliably lower in caffeine than other teas.

How Brewing Changes Everything

The numbers printed on a tea package or quoted in an article are always approximations, because how you make the tea matters at least as much as which tea you picked. Three brewing variables dominate.

Temperature is the biggest lever. Caffeine dissolves more readily in hotter water, and the effect is dramatic. When researchers steeped the same tea at 20°C, 50°C, and 100°C, the release rate at boiling was consistently the highest, with caffeine concentration climbing steeply in the first few minutes and then leveling off.⁸ Separate extraction experiments on green tea confirmed that both temperature and time increase caffeine yield, with optimal caffeine extraction happening around 80°C for 20 to 40 minutes.⁹ Nobody steeps tea for 40 minutes in real life, but the point is clear: a hotter brew for a longer time pulls more caffeine into your cup.

Time follows a curve of diminishing returns. Most of the caffeine extracts in the first three to five minutes. After that, you’re mostly pulling out additional tannins and polyphenols, which change the flavor (making it more bitter and astringent) without adding much more caffeine.

The physical form of the leaf matters too. Tea bags typically contain smaller, more broken leaf particles than loose-leaf tea, which exposes more surface area to water and speeds up extraction. Research has found that the tea bag material itself slows caffeine infusion by about 29% compared to loose tea, but the finer leaf grade inside the bag more than compensates, so bagged tea often delivers caffeine faster per minute of steeping.¹⁰ This is why a quick dunk of a tea bag can give you a surprisingly caffeinated cup.

The Genetics Question

You might assume that the two main botanical varieties of tea plant, sinensis and assamica, would differ meaningfully in caffeine. Sinensis is the Chinese variety used for most green, white, and oolong teas; assamica is the Indian variety associated with bold black teas like Assam. But when researchers in Thailand compared brewed infusions from both varieties under identical conditions, they found no significant difference in caffeine concentration.¹¹ Both came in around 20 to 27 milligrams per 100 milliliters. The variety of the plant is less important than the age of the leaves, the growing conditions, and how you brew it.

Within each variety there are hundreds of cultivars, and some do have genuinely higher or lower caffeine profiles. A few rare cultivars have been identified with very low caffeine, and plant breeders in China and Japan have been working to develop naturally low-caffeine tea plants. But these are specialty products, not what you’ll find at a grocery store.

Herbal “Tea” and the Caffeine-Free Category

Anything called chamomile tea, peppermint tea, rooibos, hibiscus, or ginger tea is not technically tea. These are tisanes, infusions made from plants other than Camellia sinensis, and they contain no caffeine because the plants they come from do not produce it. There is nothing ambiguous about this distinction: if it does not come from the tea plant, it has zero caffeine by default.

A few herbal ingredients do carry caffeine from other sources. Yerba mate and guayusa, both sometimes marketed alongside teas, contain their own caffeine along with other stimulating compounds.¹² If you’re shopping for a completely caffeine-free evening drink, check the ingredient list for these, especially in blends that combine true tea leaves with herbal additions.

Does Rinsing Your Tea Remove Caffeine?

A popular home trick, sometimes called “washing” the caffeine out, involves steeping your tea briefly, discarding that first infusion, and then rebrewing the same leaves under the assumption that you’ve flushed most of the caffeine away. The logic sounds plausible since caffeine does dissolve quickly, but the actual numbers are disappointing. One study found that a preliminary rinse reduced caffeine in the resulting infusion by only 0 to 11%.¹³ That is barely perceptible. If you need meaningfully less caffeine, a quick rinse will not get you there. You’d be better off choosing a different tea, brewing at a lower temperature, or switching to a true herbal tisane.

Decaffeinated Tea

Commercially decaffeinated tea exists, and modern methods can remove nearly all the caffeine. The most advanced processes use supercritical carbon dioxide, a method that strips caffeine effectively while preserving more of the tea’s flavor and beneficial compounds than older chemical-solvent techniques. Under optimized lab conditions, researchers have achieved caffeine removal rates above 96% from green tea leaves.¹⁴ In one study on black tea, 100% of the caffeine was removed under certain pressure and temperature combinations.¹⁵

In practice, a decaf tea you buy at the store still contains trace amounts of caffeine, usually somewhere around 2 to 5 milligrams per cup. This is because industrial decaffeination does not always reach laboratory-optimized levels, and regulations in most countries allow “decaffeinated” labels as long as the product falls below a threshold (often 97% removal). For most people this is irrelevant, but if you are extremely caffeine-sensitive or avoiding it entirely for medical reasons, even decaf tea is not quite zero. A true herbal tisane remains the only guaranteed caffeine-free option.

One tradeoff: the decaffeination process also strips out some beneficial compounds. The supercritical CO2 method, while better than ethyl acetate or methylene chloride alternatives, still removes a measurable portion of catechins and chlorophyll along with the caffeine.¹⁴ If you drink tea partly for its antioxidant content, decaf versions give you less of those compounds than the original.

Why Tea Caffeine Feels Different From Coffee Caffeine

Many tea drinkers report that the caffeine in tea produces a smoother, more sustained alertness than coffee, without the jitteriness or crash. This is not just placebo. Tea leaves contain L-theanine, an amino acid that interacts with caffeine in measurable ways. In one study, a combination of about 97 milligrams of L-theanine with 40 milligrams of caffeine (roughly what a strong cup of tea provides) improved accuracy on attention tasks and reduced self-reported tiredness compared to caffeine or theanine alone.¹⁶

Another study found that caffeine alone improved reaction time and reduced mental fatigue, but when combined with L-theanine, the effect broadened to include better working memory speed, improved sentence verification accuracy, and increased alertness ratings, all while reducing headache ratings that theanine alone sometimes caused.¹⁷ The researchers concluded that beverages containing both compounds have a “different pharmacological profile” from those with caffeine alone. In plain terms, the theanine smooths out caffeine’s rough edges and extends its benefits. This is unique to true tea; coffee contains caffeine but essentially no L-theanine.

Variation Between Brands and the Limits of Label Accuracy

If you check different brands of the same type of tea, the caffeine content can vary considerably. An analysis of commercially available tea brands using laboratory measurement found caffeine content ranging from about 0.94% to 1.5% by weight across different products.¹⁸ That may not sound like a wide spread, but at the cup level it can mean the difference between a 25-milligram cup and a 45-milligram cup from two boxes sitting next to each other on the shelf.

Most tea packaging does not list caffeine content per serving, and when it does, the number represents a single test under one set of brewing conditions. Your cup at home, brewed with your water temperature and your steeping time, may differ substantially. This is not a failing of the industry so much as an inherent feature of a natural agricultural product. Coffee has the same variability, but espresso-based drinks are somewhat more standardized because of machine-controlled extraction. Tea, prepared by hand in a mug, is the wilder variable.

Cold Brewing and Caffeine

Cold-brewed tea has become popular partly because people assume it will be lower in caffeine. The intuition is reasonable: cold water extracts caffeine more slowly than hot water, as the temperature-dependent kinetics research confirms.⁸ But cold-brew recipes compensate by steeping for hours, sometimes overnight. Over eight to twelve hours, cold water will still pull a meaningful amount of caffeine from the leaves. The final concentration depends on the ratio of tea to water and how long you leave it, but a long cold brew is not necessarily low-caffeine. If reducing caffeine is your goal, you are better off controlling steep time rather than temperature alone.

Practical Guidelines for Managing Your Intake

If you are trying to stay under a daily caffeine target (the commonly cited threshold for most adults is around 400 milligrams), tea gives you a lot of room. Even a heavy tea drinker consuming five or six cups of black tea a day would typically come in well under that limit. For comparison, two standard cups of brewed coffee can reach 300 milligrams. The main groups who should pay closer attention are pregnant individuals, people with certain heart arrhythmias, and those taking medications that interact with caffeine.

For anyone trying to minimize caffeine while still drinking true tea, a few evidence-based strategies work better than the myths:

Brew cooler: Use water below 80°C (175°F) and keep steep times short, under three minutes.
Choose older leaves: Teas marketed as made from mature leaves rather than tips and buds tend to have less caffeine in the raw material.
Skip the powder: Matcha and similar ground-leaf preparations deliver all the caffeine in the leaf. Steeped loose-leaf tea, where you discard the leaves, leaves some caffeine behind.
Go herbal after noon: Rooibos, chamomile, and other true tisanes remain the only guaranteed zero-caffeine route from a teacup.

These adjustments give you far more control than trying to pick the “right” tea type, because as the research consistently shows, the overlap in caffeine content between types is larger than most people expect.

1
PubMed Central. JA Regulates Caffeine Biosynthesis in Tea Leaf for Resistance Against Fungal Infection and Antagonises With GA to Balance the Defence–Growth Trade‐Off via CsDELLA‐JAZ‐MYC2‐MYB184‐TCS1 Module
2
Food Chemistry. Correlation between leaf age, shade levels, and characteristic beneficial natural constituents of tea (Camellia sinensis) grown in Hawaii
3
PubMed. Caffeine content of common beverages
4
PubMed. Total phenol, catechin, and caffeine contents of teas commonly consumed in the United kingdom
5
Journal of Analytical Toxicology. Caffeine Content of Brewed Teas
6
PubMed Central. Production of theophylline via aerobic fermentation of pu-erh tea using tea-derived fungi
7
Subtropical Plant Science. Research Progress in the Variations of Caffeine During the Post-Fermentation of Pu-erh Tea
8
Journal of Chemical Education. The Art of Steeping a Cup of Tea: Exploring Temperature Effect on Caffeine Release Kinetics Using 1H NMR in Undergraduate Laboratories
9
PubMed. Extraction of antioxidants and caffeine from green tea (Camelia sinensis) leaves: kinetics and modeling
10
Food Chemistry. Kinetics of tea infusion. Part 3: the effect of tea bag size and shape on the rate of caffeine extraction from Ceylon orange pekoe tea
11
Food Chemistry. Caffeine in Chiang Rai tea infusions: Effects of tea variety, type, leaf form, and infusion conditions
12
PubMed. More than just caffeine: psychopharmacology of methylxanthine interactions with plant-derived phytochemicals
13
Journal of Agricultural and Food Chemistry. Rinsing Tea before Brewing Decreases Pesticide Residues in Tea Infusion
14
LWT – Food Science and Technology. Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves
15
PubMed Central. Effects of processing parameters on the caffeine extraction yield during decaffeination of black tea using pilot-scale supercritical carbon dioxide extraction technique
16
PubMed. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness
17
PubMed. The effects of L-theanine, caffeine and their combination on cognition and mood
18
Future Postharvest and Food. Assessment of Caffeine Content in Tea and Coffee Brands Within the Palestinian Market Using HPLC Method