Matcha To Assam: How Much Caffeine Is Really In Your Tea?

Many tea drinkers assume caffeine levels neatly follow a pattern: white tea has the least caffeine, then green, then oolong, and black tea contains the most. It’s a convenient idea that is often echoed on packaging and wellness sites.

Although this simple theory, that lighter-colored teas have less caffeine, is appealing, the reality is less straightforward. Caffeine content doesn’t really depend on tea type; factors like growing conditions, the amount of tea leaves used, and brewing style are the important factors to consider.

Using typical brewing practices and reliable scientific data, we’ve created a detailed chart highlighting caffeine levels across various tea types.

This means that caffeine levels across different teas frequently overlap. For example… some white teas can actually have more caffeine than some black teas.

Factors that affect caffeine

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When you are selecting and brewing your own cup of tea, these are the factors that most affect how much caffeine you are getting.

• Brewing Methods

  • Temperature: Higher temperatures extract significantly more caffeine. For example, brewing tea at 160°F (70°C) results in about 40% less caffeine than brewing at 212°F (100°C) for the same time. [Source]

  • Brew Time: In the first minute of brewing only about 18% of the caffeine is released. After 5 minutes, roughly 70% of the total caffeine is extracted. So, a shorter brew time will result in less caffeine.

  • Amount of tea: How much tea you use, of course, affects the amount of caffeine. With loose leaf, it's easy to go overboard and use a lot more tea than is necessary!

• Leaf Form and Size
  Due to increased surface area, finely broken leaves (like those in tea bags or broken leaf loose tea) release caffeine more quickly than whole leaves. This doesn’t necessarily mean more total caffeine; it just infuses faster.

• Processing Techniques
  Roasted teas like Hojicha have less caffeine. The roasting process "boils off" caffeine compounds, which explains why hojicha is significantly lower in caffeine despite being made from green tea leaves. [Source]

• Growing Conditions
  Cultivar, altitude, shading, and harvest time all matter. Teas like Gyokuro are shade-grown to increase chlorophyll and amino acids — and that shading also boosts caffeine production. Similarly, Assam varietals tend to be naturally higher in caffeine than Chinese ones. You can read more about this from this [Source]

In short: how you brew your tea has more influence on caffeine levels than the color or type of leaf alone. Temperature, time, and quantity determine whether your cup ends up mild or strong, regardless of whether it's green, black, or white.

Tea & Caffeine — Common Myths Debunked

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• White tea has the least caffeine of all teas.
  Several lab analyses show that white, green and black teas overlap widely in caffeine (14 – 61 mg per 6‑8 oz), with no consistent trend by type. A strongly brewed white tea can equal or exceed many black teas. [Source: pubmed]

• You can remove most of the caffeine by discarding the first steep.
  There is some truth to the idea of removing some caffeine by doing a quick "rinse". However, the effects are smaller compared to traditional decaffeinating methods. As the chart above shows, after 1 min, you extract around 18% of the caffeine. Since the Full Steep of 5 minutes only extracts around 69%, your effective decaffeination with a 1-minute rinse is around 30%. Which might be enough for you!

• Herbal teas are just like decaf tea.
  True herbals (chamomile, rooibos, etc.) contain zero caffeine. Because they don't come from tea plants, and their respective plants don't contain caffeine. Decaffeinated Camellia sinensis still carries 2 – 12 mg per cup because the process cannot remove it all. [Source]

• Matcha has less caffeine because it’s green tea.
  Matcha powder delivers the whole leaf, not just an infustion. So you are getting everything the leaf has to offer. A normal 2 g serving yields ≈60 – 80 mg — often more than a standard green‑tea infusion and approaching coffee levels. [Source]

• Stronger flavor means more caffeine.
  Taste intensity is driven by polyphenols, amino acids, and oxidation level, none of which is directly related to caffeine. A delicate, umami‑rich gyokuro can out‑caffeinate a bold, malty black tea brewed lightly.

• Iced tea has less caffeine than hot tea.
  That depends on how the iced tea is made.

  • Hot‑brew‑then‑chill: If the leaves are infused in near‑boiling water (≈ 200 °F) and the liquor is simply refrigerated, the caffeine content is identical to the hot brew.
  • True cold brew (room‑ or fridge‑temperature water, 6‑12 h): Lower water temperature slows caffeine extraction, even with a long steep. Laboratory tests found cold infusions delivered about 40 – 70 % of the caffeine of a 5‑minute hot brew. [Source] and [Source]

Tips to Increase Caffeine

• Leaf Selection: Choose smaller leaves with lots of tea buds (Golden Tips), or shade-grown teas like Gyokuro.

• Amount: Use more tea when brewing; an extra teaspoon will double your caffeine.

• Steeping: Steep for at least 5 minutes with boiling water

Tips to Decrease Caffeine

• Leaf Selection: Choose larger leaves with less teabuds

• Amount: Find teas with more intense flavor and use fewer leaves

• Steeping: Use lower temperature water, or even cold brew the leaves.

• Rinsing the Leaves: Consider using boiling water to steep the leaves for 1 minute. Then discard, and steep with lower temperature water for 3 or 4 minutes. This may negatively impact the flavor of the tea, but you might be able to find a balance.

• Blend with herbals: You can mix rooibos (or other herbal blends) with tea for a "half-caf" option. This essentially lets you use less tea while maintaining a robust flavor.

• Avoid caffeine altogether: herbal blends like rooibos or chamomile are a completely caffeine free and flavorful option.

The Takeaway

While many expect (and hope for) a neat progression from white to black in terms of caffeine strength, the reality is shaped by a mix of factors—leaf variety, growing methods, processing techniques, and especially how the tea is brewed.

Now that you understand the nuances of brewing dynamics, you can take complete control over your tea experience. Whether you're seeking a gentle lift or a serious jolt, it's all in your hands… and in how you brew it.