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When the world seems to favor early risers, as a night owl, I rely on caffeine to function as a normal human being. Billions of people around the world rely on caffeine in the morning to start their day.
Others consume caffeine in situations when they need to stay alert and focused. It is a lifesaver when you’re pulling an all-nighter before an important exam. In any case, caffeine is a quick way to make you more alert, improve concentration, and help you feel more energetic.
As it happens, tea – a source of caffeine – is the second most common beverage after water. Which makes caffeine one of the most commonly consumed substances in the world.
Caffeine is also found in many other everyday foods and beverages, such as chocolate bars, energy drinks, or coffee. It is popular for its energy-boosting effects, but it’s also addicting. According to various studies, research and surveys, caffeine can have health benefits, as well as a negative impact on people’s health.
The caffeine content in any beverage can make a huge impact on your mind and body, making it essential to learn about it. Keep reading to find out how caffeine works, what health benefits it may have, its downsides, and the amounts of it in different teas.
What is caffeine, and what does it do?
Caffeine is a natural stimulant that you can find in leaves, fruits, and beans of various plants. There are around 60 plants in total that contain caffeine, including tea plants.
You will find caffeine in some processed and packaged foods such as chocolate bars, coffee, nutrition bars, energy drinks, etc. Some prescription medications like cough syrups and slimming tablets also contain caffeine as a key ingredient.
How does caffeine work?
Caffeine is a stimulant. It increases brain function and especially affects the central nervous system. Besides improving alertness and combating fatigue, caffeine also boosts the circulation of chemicals like cortisol and adrenaline.
Between 15 to 30 minutes after consuming caffeine, your bloodstream absorbs caffeine. This is when the effects of caffeine on the brain reach their peak.
Caffeine blocks the effects of adenosine, a neurotransmitter. Adenosine is responsible for the feeling of tiredness. Shortly after, you will experience various short-term effects: increased breathing and a higher heart rate. Caffeine can also increase your physical energy levels and make you more alert.
Positive effects of caffeine
Caffeine consumption is also helpful in lifting the mood, improving metabolism, and enhancing brain function. You can drink caffeine-infused beverages in order to increase your productivity and performance. The effectiveness of caffeine varies from person to person and may last for up to 12 hours at most.
Negative effects of caffeine
Some people who consume a lot of caffeine on a daily basis can experience symptoms like irregular heartbeat, restlessness, or insomnia. It is also possible for you to end up developing a tolerance to caffeine just like you would to any other drug. With time you will need more and more caffeine in order for it to have the same effect.
How much caffeine is it okay to consume in a day?
Typically, you should only take 400 mg or less caffeine in a day. Consuming more caffeine than the recommended maximum daily amount can lead to adverse effects.
How much caffeine is in green tea?
On average, the caffeine content in an 8-ounce (230ml) cup of green tea is around 38 mg, but this may be anywhere between 20 mg and 50 mg. According to health experts and nutritionists, consuming multiple servings of green tea daily is fairly healthy. This is because the amount of caffeine in green teas is quite low compared to other caffeinated beverages such as energy drinks and coffee.
What impacts the caffeine contents in green tea?
Caffeine is a naturally-occurring chemical, its amount depends on the variety of the tea plant. Growing conditions and processing method also has an impact.
Green tea varieties and terroir
If you read my blog, you already know that green tea comes in many varieties, such as matcha, bancha, sencha, and others. The different varieties of the tea plant don’t significantly differ in the amount of caffeine they contain. However var. assamica (Indian variant) consistently has somewhat higher levels of caffeine than var. sinensis (the Chinese variant).
Japanese green tea also usually has more caffeine than Chinese green tea, especially ones that are shaded for a few weeks before plucking – matcha or gyokuro. The fact that Japanese use a heavier dose of nitrogen fertilizer also contributes to the higher levels of caffeine.
When tea leaves are plucked also matters. Plucked in the cooler season, tea leaves contain a lower concentration of caffeine.
The form of your green tea
Green tea bags are often higher in caffeine than loose-leaf green tea. This is usually the result of crushing tea leaves for bagging. Powdered matcha green tea, contains more caffeine than both loose leaves and bagged green tea.
Loose leaf tea infuses more slowly, it leaves some caffeine and flavor for subsequent infusions – that’s why it can be brewed multiple times. The dust in tea bags releases everything at once.
The types of leaves
The type of leaves also largely affects the caffeine content. Your tea will have a lower level of caffeine if you brew it with older leaves. On the other hand, younger tea leaves brew into more heavily caffeinated drinks, because the caffeine is more heavily concentrated in the smaller young leaves.
The brewing method
Lastly, but most importantly, the brewing method also has its fair share in deciding how much caffeine you’re going to be consuming with each serving.
Essentially, the longer you brew your green tea, the more caffeine it will contain. If you use more tea leaves, you will also get more caffeine.
Same with water – higher water temperatures extract more caffeine from your tea leaves. Asa reminder – green tea should be brewed at around 80 degrees Celsius.
Caffeine in other teas
The level of oxidation in tea is the primary differentiating factor between tea types. Unsurprisingly, different types of tea contain different amounts of caffeine.
Black tea
On average, one cup contains around 47 mg of caffeine. However, this amount can vary, and get up to around 90 mg of caffeine per cup.
Oolong tea
Oolong tea is one of the tea varieties that have a highly variable caffeine content, which may get quite confusing at times. There are 5 main factors that determine how much caffeine you’re getting from oolong tea:
- Water temperature
- Time spent steeping
- The number of re-steepings
- Harvest time of oolong leaves
- Tea leaves processing
Most of the time, the caffeine content of oolong tea is less than black tea and more than green tea. This means that a typical drinking cup of oolong tea will contain between 45 mg and 70 mg of caffeine.
But depending on the above-mentioned factors, the caffeine content can range anywhere between 10 mg and 102 mg per serving.
Jasmine Tea
Jasmine tea refers to tea leaves infused and scented with jasmine. They come as a blend of jasmine infusion with another type of tea. The infusion of jasmine may enhance the flavors of regular tea. Jasmine itself doesn’t contain any caffeine.
But jasmine tea may contain caffeine, depending on the type of tea leaves used for infusion with jasmine. This blend with other teas has between 20 mg and 60 mg of caffeine per serving.
Again, this will vary depending on the type of jasmine tea, time of harvest, and processing.
Decaffeinated green tea
Around 2 to 4 mg of caffeine is present in a single tea bag of naturally decaffeinated green tea. However, the caffeine content in your drink also largely depends on the infusion time. Therefore, the caffeine levels will keep increasing as you keep infusing.
You may be wondering why decaf green tea still has some caffeine. Well, it is because decaffeinated teas are not the same as caffeine-free teas.
Decaffeinated green tea means that it has most of its caffeine removed through a natural process. Usually, a high-pressure extraction process employs CO2 to selectively remove caffeine while keeping the flavor components intact.
Caffeine content – tea vs. coffee
For most people, coffee is the first thing that pops up in their minds upon hearing the word “caffeine”. It is one of the most popular caffeinated drinks in the world, with significant effects on the mind and body.
On average, there is around 95 mg of caffeine present in a regular cup. That’s around double the amount that the usual cup of green tea contains.
While normally it’s not recommended to take more than 4 cups of coffee, you should be fine taking as many as 6-8 cups of green tea. The effects of caffeine from green tea are somewhat different too.
How different is caffeine in tea and coffee?
Sure, caffeine is caffeine regardless of where it is contained. However, caffeine consumed through tea works a little differently than caffeine consumed through coffee.
In fact, the effects of tea are much slower and gentler than coffee. Coffee gives you a quicker boost of energy, and you experience worse withdrawal symptoms.
The energy boost from tea is more gradual and gentler as the body absorbs this caffeine in a different way. In this case, the caffeine binds with L-theanine, an amino acid that delivers the effects of caffeine with better control. This is the reason why you wouldn’t normally experience jitters from tea as you would from coffee.
It only takes a few minutes for the bloodstream to absorb the caffeine from coffee. As a result, you experience an intense and quick burst of energy after drinking caffeine.
Bottom line
Tea offers different experiences and tastes, but it also contains caffeine. The amount of caffeine in green tea is lower than that of coffee, but it’s still quite significant. Especially for people with caffeine sensitivity. Even decaf green tea contains traces of caffeine.
The biggest impact on the levels of caffeine in tea has, in fact, its preparation. The longer you steep and the more tea leaves you use, the more caffeine your tea will contain. For the least amount of caffeine, cold-brewed tea may be a good option.
There is also a difference between the caffeine in teas and coffee. Coffee provides an instant burst of energy while the effects of tea are much slower and gentler. You may want to choose green tea over coffee next time. Learn how to make it correctly if you find that it doesn’t taste that good!
Let me know in the comments below – what are your reasons for drinking tea?
