Green Tea: What's In It and Why It Matters

Green Tea: What's In It and Why It Matters

Green Tea: What's In It and Why It Matters 


Does green tea have caffeine? What should my caffeine intake be anyway? How is it different to black tea?


Without an afternoon spent on research and data, it's hard to know if green tea is the right brewed drink for you.

We've compiled all the answers (including a few you didn't know you needed) in one place. Welcome to everything you could possibly need to know about green tea. From the caffeine content to the natural nutrition of this healthy and invigorating type of tea. Did you know that several of our energy teas are made with green tea?

Green tea caffeine

 HIGH CAFFEINE TEAS  We get it - you can't function before caffeine hits your bloodstream. Good thing Zest has more caffeine than coffee, plus your stomach won't hate you for drinking it.   ENERGY: 3X the amount of caffeine found in regular teas FOCUS: L-Theanine for all-day, steady alertness HEALTH: No surgar and made with completely natural ingredients  SEE PRODUCT PAGE
The 411 on Green Tea

Just in case you're really clueless, green tea is a drink made by infusing leaves with water. It's that simple.

Consumed for centuries in China and Japan, it's now one of the most popular caffeinated beverages around the world. While our reliable cuppa Joe, comforting black tea, and sweet cola remain the go-to choices for energy, we think that green tea shouldn't be overlooked.

Green tea contains caffeine and amino acids for energy and nutrition. The effects of caffeine in green tea might just surprise you. More on that below.

Green tea contains caffeine and amino acids for energy and nutrition


Does Green Tea Have Caffeine?

Yes, caffeine is in green tea... albeit nowhere near as much as a cup of coffee.
Per 8 ounce serving of standard green tea (the kind you can make from green tea bags bought at the grocery store) there's roughly 28 mg of caffeine.
To put that into perspective:


  • Standard green tea - 28mg
  • Matcha green tea - 70mg
  • Standard brewed coffee - 96mg
  • Zest high-caffeine green tea - 135mg


Tea usually contains a moderate amount of caffeine at most, with less caffeine in a standard cup of green tea and more in a cup of frothy matcha. Typically, matcha has the highest caffeine content of all green teas, as it's made by whisking powdered tea leaf into water instead of infusing it and removing it.

However, there is an exception. High energy teas, like our green tea blends at Zest Tea, contain boosted caffeine levels. Up to 135mg per 8 ounce serving!

And before you ask, no this isn't a dangerous level of caffeine to drink per day. In fact, the FDA recommends an average adult with a healthy diet consumes no more than 400mg of caffeine per day.3  Phew.

How Green Tea is Made

Green tea is made from the leaves of Camellia sinensis plant, better known as simply the tea plant. And yes, that's the same tea plant that produces the tea leaf for black tea, white tea, oolong tea, etc.

How green tea is made

What differs between these tea types is the process the leaves go through after they are harvested.


  1. The leaves are harvested
  2. They're sun dried for a short period of time
  3. The leaves are oxidized
  4. The leaves are fired to prevent more oxidation
  5. The leaves are shaped, dried and cut
  6. Your tea bags are filled and ready to brew


Steps 3 and 4 are really important.

Lightly crushing and bruising the leaves exposes them to oxygen. The level of oxidation is what separates a green tea from a black tea.  Black teas have been heavily oxidized, so the leaves turn from green and fresh to brown and rich. The flavor changes too.


Of all the tea types, green tea is the least oxidized. That's why it has that bright, refreshing and grassy taste.

Once the right level of oxidation is met, the leaves are fixed to stop them oxidizing further. Intense heat is applied swiftly to do this - typically by pan firing or oven firing.


Why Green Tea is So Popular

Green tea is quite popular, especially matcha, and especially with celebrities. Gwyneth Paltrow's go-to caffeinated drink is an unsweetened iced matcha latte and Brad Pitt expressed his love for the whole ritual of making matcha in an interview with GQ. He's since launched his own cold brew tea brand, so maybe it isn't just another phase.

Celebrities drinking green tea

You might have seen green teas recommended as part of a diet to lose weight too.

This great love for the greenest of teas is partly thanks to the awesome health benefits of some key nutrients.

Matcha Tea

Green Tea Contains Much More Than Caffeine...

There are two pretty important nutrients in green tea besides the caffeine stimulant content.


  • An amino acid naturally found in tea leaves,
  • Slows and maintains caffeine steadily (reduces the crash),
  • Promotes creativity, productivity, focus and calm through enhanced alpha brain waves.
  • Epigallocatechin gallate (EGCG) is a catechin found in green tea,
  • It has anti-inflammatory and antioxidant effects that combat a range of diseases,
  • EGCG is linked to weight-loss, heart health, brain health and protecting against cancer in numerous studies.


Currently, the data about the amino acid content you get from drinking green tea is super promising. More research is needed, of course, but you can see why green tea is famed for a good diet and great overall health.

How to Make Green Tea

The method for making green tea differs slightly to how you would make black tea. But it's certainly not rocket science. Here's a step by step guide to brewing the perfect cup of tea, whether you're using green tea bags or loose green tea leaves.


How to make green tea 


If you go straight from drinking coffee to drinking green tea, you're going to notice quite a difference - not just because green tea contains less caffeine.
Green tea flavors are often described as:

  • Fresh and green (no, really),
  • Seaweed, grass and other leafy greens,
  • Zucchini, green grapes, honeydew melon and other sweet veggies,
  • Slight earthy and hay notes.

Green tea flavor

Just search for single origin green teas that bloggers have reviewed and you'll find similar related flavors too. Compared to other tea drinks, green tea is more refreshing than hearty and comforting.

There's often a slight bitterness about green tea, but waiting until the water is roughly 80°C instead of 100°C will help to reduce that.

The aroma of brewed green tea is naturally green and grassy. It can sometimes be vegetal too, but don't worry, it's nothing like blended veggie smoothie drinks. Bleh.

Side note: decaf green teas are without the majority of the caffeine content. There's usually only a milligram or two of caffeine left after the decaf process. Unfortunately, depending on the decaf method for removing caffeine in green tea, the flavor may be altered too. Ethyl acetate removes the stimulant but can leave a chemical-like taste in your mouth.

Pouring green tea

Go Green with Zest! 

Green teas are sounding pretty great so far... except there's not much caffeine to go around.

Enter, Zest Tea. This is the place to get your hands on highly caffeinated beverages, with all the healthy components of green tea with a little extra energy.

We have two tasty green teas to brew:

Zest Tea


Plus ice cold, ready-to-drink (but just as healthy) green teas in several flavors. And if they're not to your tastes, then our black teas are worth checking out too.

To help you visualize how the amount of caffeine will impact your energy levels and mood, here's a quick comparison of standard green tea and Zest green tea.

Green tea vs Zest Green Tea


What caffeine in green tea feels like 

28 mg of caffeine is certainly more than a decaf tea, but still nearly half what you'd get from a standard black tea. The low caffeine content, high L-Theanine content, and green flavor leave you feeling refreshed and calm.

You'll find the energy and clarity of mind to take a walk to the park. Maybe stop for a quick meditation. Feed the birds. Enjoy life. Then back home again.

It's certainly pleasant.

What 135 mg of caffeine feels like

One serving (8 oz) of Zest Tea has much higher caffeine levels. 135 mg of caffeine feels like more caffeine from coffee!

You get that wave of energy and productivity from the caffeine, plus calmness and focus from the amino acids. There's no crash.

If a normal cup of green tea is like a gentle walk through the park, a cup of Zest Tea is like running a marathon while also replying to your work emails. And still feeling naturally calm and refreshed. No sweaty armpits either.

Rapid Fire FAQs

What has more caffeine, coffee or green tea?


Does green tea keep you awake?

Somewhat. It's low in caffeine compared to other tea types.

Why green tea is bad for you?

Consuming any food or drink in excess is bad for you.

Is it OK to drink green tea before bed?

Yes, amino acids in green tea may even improve sleep quality. If you are sensitive to caffeine, it may keep you up however.

Which is better, black tea or green tea?

Both are great, with different benefits and flavors.

Which tea is highest in caffeine?

High energy teas have up to 150mg of caffeine per serving.

Is green tea healthier than coffee?

Yes, if you drink coffee with milk and sugar.

What happens if I drink green tea everyday?

You'll enjoy a nice cup of green tea daily, rehydrate your body, and consume a small amount of caffeine.

Is it OK to drink green tea everyday?


Can I drink a green tea on an empty stomach?

Yes, but it might not feel great.

When should you not drink green tea?

1) Before bed - if you're sensitive to caffeine, drink sleep tea instead.

2) On an empty stomach - the acidity can make you feel queasy.

3) Directly after a meal - tea loses health benefits when it binds with iron-rich foods.


What time is best to drink green tea?

Between meals during the day.

Can I drink a green tea before breakfast?

Yes, or with breakfast.


  PLANT POWERED ENERGY DRINKS  We get it - you can't function before caffeine hits your bloodstream. Good thing Zest has more caffeine than coffee, plus your stomach won't hate you for drinking it.   ENERGY: 150 mg caffeine - more than coffee FOCUS: L-Theanine for all-day, steady alertness HEALTH: Low to no surgar, and made with completely natural ingredients  SEE PRODUCT PAGE



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