The caffeine content of tea depends on many factors including oxidation levels, the type of tea, how long you let it steep, but as a general rule, the darker the tea, the higher the caffeine content. Knowing the caffeine content is an important factor in choosing which tea to drink and many people ask which tea contains the most caffeine. Coffee and tea both contain caffeine, but a cup of coffee contains more. If you like a boost you can still get it from a cup of tea. On the other hand, you may want to reduce your caffeine intake and there are teas that contain far less than others. While there are some potential health benefits to consuming moderate amounts of caffeine, drinking too much of it is hard on your heart and other organs. If you are worried about side effects or withdrawal symptoms, you should seek medical advice. Tea can provide the pick me up of coffee without causing anxiety or sleep deprivation. It may also help with heart disease and Type 2 Diabetes.
How does tea caffeine content differ from coffee?
People often get into the tea versus coffee debate when comparing caffeine consumption. Tea differs from coffee because when it is infused, the caffeine combines with tannins which reduce and stabilises its effect.
When you brew coffee beans, the chemical process is different.Tannins prevent a rapid release of caffeine and it is absorbed over a longer period of time which makes the effect more regular and lasts longer. In tea, the cardiovascular system and central nervous system are stimulated by caffeine because it enlarges the diameter of the blood vessels in the cerebral cortex in the brain.
With coffee, on the other hand, the effect is direct to the bloodstream through the coronary system, which results in a stimulated heart rate. Put in simple terms, tea is a stimulant, not an excitant. It helps keep your mind sharp, boosts concentration, eliminates tiredness, and boosts brain activity.
Tea helps keep you hydrated
Caffeine doesn’t generally dehydrate you unless you consume more than 5 to 6 cups of a drink at a time. This is why energy drinks can be dangerous.Tea has been shown to actually be more healthy for you than water alone in some cases because it hydrates while providing antioxidants.Tea can create a calmer but more alert state of mind. Extensive research has shown that the combination of caffeine and L-Theanine, a naturally-occurring amino acid found in tea, improves reaction time and memory, while increasing focus and concentration (think of monks meditating). This helps increase memory, function, focus and concentration.
So which brewed tea contains the most caffeine? The general rule is that the darker the liquor of the tea, the more caffeine it contains. Green and white tea contains less caffeine than black varieties. Caffeine in iced tea is the same as hot tea, depending on the variety of tea you are using. True teas are all made from the leaves of the same tea plant – Camellia Sinensis – steep time, oxidation levels, processing method, where and how it is grown all affect caffeine levels.
There are six different types of tea which include White, Green, Yellow, Black, Oolong & Puerh. Herbal varieties do not contain caffeine and are called tisanes.
The average cup of tea contains 236 ml or 8 ounces of liquid. In that cup, in general, you can expect:
- Black tea – between 60 and 90 mg
- Oolong – between 50 and 75 mg
- Green tea – between 35 and 70 mg
- White tea – between 30 and 55 mg
- Matcha – around 70mg
To put that into context, coffee contains between 70 and 140 mg per cup while an espresso shot contains about 65mg.
Steep time and method
The amount of caffeine contained in a cup of tea largely depends on how long you steep it for. This holds true for all tea varieties. Whether you use a tea bag or loose leaf tea, the longer you let it steep, the more caffeine will be released into the liquor. If you agitate the leaves by swirling them around, you will also release more flavour into the tea. That process also increases the caffeine content. If you use more tea leaves than recommended, caffeine levels will be higher than normal. The temperature of the water you use also has an effect on caffeine levels. Different teas are brewed at different temperatures and the hotter the water, the higher the caffeine levels. If, for example, you brewed a green tea for 10 minutes at 100 degrees Celsius (please don’t steep your Green tea at 100 degrees!!), it would contain more caffeine than Oolong, which normally has higher caffeine content. If you like a strong cup of tea, just be mindful that you are getting a substantial dose of caffeine with it.
Oxidation and its effect on caffeine content
A key factor in tea’s caffeine levels is the levels of oxidation it has gone through. Oxidation is a chemical reaction that causes tea leaves to turn brown in colour. The process affects the colour of the tea as well as caffeine levels, flavour, aroma, palette, and after taste of the drink. Oxidation begins as soon as the leaves are plucked, this continues during the “bruising process”. This is where the leaves are tossed, crushed, or rolled to create cracks on the flesh of the leaf, allowing the leaves to gain greater exposure to oxygen. Oxygen in the air reacts with the Camellia Sinensis leaves’ enzymes causing them to turn darker in colour.
The colour of the tea depends on the level of oxidation. The more you oxidise tea, the darker the colour. Black tea is the most oxidised and contains the most caffeine. It is followed by Oolong and green tea and finally white tea, which has the lowest oxidation levels and therefore caffeine content.
Black Tea caffeine content
Black tea, which can be consumed as a single origin beverage or a blend such as Earl Grey Blues or Fine Breakfast or Fine Chai, is the most oxidized, flavourful and strongest tea. The caffeine in black tea is the highest out of all varieties. There are many varieties of black tea that come from Australia, China, India, Taiwan, Korea, Iran, Turkey, Nepal and Sri Lanka. Black tea has Antioxidant Properties and may boost heart health by lowering bad LDL cholesterol and blood pressure. It may also help reduce sugar levels, risk of stroke and the risk of cancer. Black tea is brewed at high temperatures between 90 and 100 degrees Celsius. With a high-grade pure tea, you can get multiple steeps for a single cup. If taken black, Chai is brewed at the same temperature. Each 250 ml cup of black tea contains between 60 to 90 milligrams of caffeine.
Oolong Tea caffeine content
Oolong tea lies in between green and black tea with quite high levels of oxidation. This is another tea which may be roasted or toasted which alters the flavour profile and caffeine content.Oolong is a Chinese tea mainly originating in the Fujian province. There are some sub-varieties found in Vietnam and Taiwan, while India also produces Assam varieties according to Oolong methods.
Oolong is sem-oxidised. It is semi-dried in the sun before twisting, and curling to accelerate oxidation. It is then usually fired to give it a roasted taste. The process is repeated over and over to achieve the correct flavour profile.The degree of oxidation, which varies according to the chosen duration of time before firing, can range from 8–85%, depending on the variety and production style.This type of tea has been linked to lowering cholesterol, blood sugar levels, helping to prevent allergies and aid weight loss. Each cup of Oolong contains between 50 and 75 mg of caffeine.
Green Tea caffeine content
Green teas are a very popular choice with tea drinkers who look to enjoy sipping on a mild soothing beverage that has lower caffeine levels. Green tea does not undergo a heavy oxidation process and it is brewed at between 75 and 80 degrees Celsius, meaning that it is lower in caffeine. It is brewed for between 30 seconds and three minutes, two or three times depending on the variety.
Green tea can have a marine or vegetal flavour, often with sweet or floral notes, depending on the type of tea. It must be brewed correctly to avoid scalding the leaves, or excessive tannin release, leading to a very bitter drink, regardless of the quality of the tea leaves. Green tea is primarily grown in China, Japan, and Korea. Examples include Sencha, Gyokuro, and Hojicha. It has been linked to well being, lower blood sugar levels, LLD cholesterol, heart health, and immunity. It is low on caffeine, containing 35-70 mg per cup. Hojicha is lower in caffeine due to the roasting process. Caffeine in yellow tea is slightly lower in content than green tea.
White Tea caffeine content
White tea is subject to minimal oxidation, if any at all. The caffeine in white tea is significantly lower than Green, Oolong, or Black teas. There are various ways of defining white tea. Some experts say that it is simply sun-dried with no additional processing. Others classify it as tea made from immature buds that have not yet opened fully and are then allowed to dry in the sun. Others say that that White Tea includes very young leaves that are steamed or roasted before being dried out. What all experts do agree on is that white tea is not subjected to the rolling or oxidized, meaning it has much lower caffeine content.
White tea actually gets its name from the silvery, feathery appearance of the unopened tea buds. It is actually yellow in colour when brewed. White tea is mostly grown in the Fujian province of China. There is also another variety made from the Camellia Taliensis in Yunnan. White teas include Pai Mu Tan, (also known as Bai Mu Dan or White Peony), Shou Mei, and Silver Needle tea. They are brewed at 70-80 degrees Celsius and contains only 30 to 55 mg per 8 oz cup. White teas are more mild and sweet in taste.
Matcha caffeine content
Powdered teas, especially green matcha, have quite a large caffeine kick. In fact, the caffeine in matcha competes with coffee and some people who need an energy boost will opt for matcha instead of an espresso. While matcha is a bright green tea, its caffeine levels are almost twice the level as those found in regular green teas. One of the many factors that set matcha apart from other teas is that it is made from high-grade shade-grown tea leaves.The process to harvest takes up to 20 days and begins when the tea shoots and bushes are covered to prevent any direct sunlight hitting them.
Like Gyokuro, this makes the plant grow slower and produce more chlorophyll to combat the reduced light, which turns the leaves a darker, deeper, and richer shade of green. The technique causes the production of amino acids, including theanine. Harvesters pick only the best and finest quality shoots. The leaves are laid out flat to dry and will crumble and become known as tencha (碾茶). The Tencha then has veins and stems removed before it is stone-ground into the vibrant green soft powder that is known as Matcha.
The grinding process is slow because the millstones are warmed. They must not get overly warm as this might alter the aroma and taste of the matcha. An experienced grinder may need up to an hour to produce just 30 grams of matcha. And now you know why it is expensive! This high grade of Matcha is also known as ceremonial matcha, used in traditional tea ceremony. Matcha was first brought to Japan by Chinese Buddhist monks in around 1200. At the time, tea was powdered and beaten by the Chinese, but they changed the practice while the Japanese kept it.
A cup of matcha can contain upwards of 70 mg of caffeine.
Herbal and fruit tisanes contain no caffeine
Herbal teas and fruit teas are not classified as “true teas” because they are not made from the Camellia sinensis plant.As the name suggests, they are made from herbs, fruits, grasses and spices and do not contain any caffeine because they do not undergo the oxidation process. Their correct name is ‘tisanes’.
Tea of lower quality contains more caffeine
Tea quality is judged according to tea grades. The finest teas are Orange Pekoe (OP) followed by Broken Orange Pekoe (BOP) and a Fanning (F) which is smaller than BOP.Dust (D) is the lowest grade of tea available and is usually what goes into tea bags. So, how much caffeine is there in tea bags? Put simply, he darker and more broken the leaf, the more caffeine it secretes. On the flipside, tea bags prevent the full flavour of the tea infusion.
Do Growing Methods Affect Caffeine In Tea?
It’s not all about how you steep your tea. A drink’s caffeine levels are also influenced by how the leaves are grown.Shade-grown teas like Matcha have higher levels of caffeine. This is because of shifts in chlorophyll and amino acids that take place as the plants are shaded from sunlight before harvest.
South American Yerba Mate contains Matteine
People wanting to avoid all stimulants should know the South American drink Yerba Mate contains a substance similar to caffeine. This is called matteine.Yerba Mate is related to the holly plant and grows in Brazil, Paraguay, Uruguay, and Argentina.It has a herbal and minty taste but is also earthy. The leaves are dried by blowing hot air over them or the traditional method of drying over burning wood.