Does Black Tea or Green Tea Have More Caffeine?

December 4, 2025 •

3 min read

Despite originating from the same plant, black tea is generally assumed to have more caffeine than green tea due to its processing. However, recent data suggests that an average cup of black tea (40–70 mg) contains a surprisingly similar amount to some green teas (20–45 mg), with brewing methods often playing a bigger role than the tea type itself.

Quick Summary

This article explains how different processing methods, plant varieties, and brewing techniques influence the caffeine content in black and green teas. It details the average caffeine ranges and highlights specific exceptions like matcha, providing a comprehensive overview for tea drinkers.

Key Points

Black Tea vs. Green Tea Caffeine: As a general rule, black tea has more caffeine than green tea, but numerous factors can influence the final amount.
Oxidation and Extraction: The oxidation process black tea undergoes makes caffeine more readily available for extraction during brewing.
Brewing Matters Most: Water temperature and steeping time are the most controllable factors influencing caffeine levels, often outweighing the type of tea.
Matcha is the Exception: Shade-grown and consumed whole, matcha green tea contains a higher concentration of caffeine than a standard cup of black tea.
L-Theanine for Calm Focus: Green tea's L-theanine content creates a smoother, more balanced energy boost compared to the sharper spike from black tea.
Reduce Caffeine Intake: Lowering water temperature and shortening steep time are effective ways to decrease the caffeine in your brew.
Loose Leaf vs. Tea Bags: Whole loose leaf tea typically extracts caffeine more slowly than the smaller, broken leaves found in tea bags.

Black vs. Green Tea: The Core Difference

All true teas—black, green, white, and oolong—come from the leaves of the Camellia sinensis plant. The key distinction lies in their processing, particularly the level of oxidation. Black tea is fully oxidized, while green tea is not. This oxidation gives black tea its darker color, stronger flavor, and generally higher caffeine content. Green tea's lack of oxidation preserves its green color and milder taste.

The Impact of Oxidation on Caffeine

The oxidation process in black tea can make its caffeine more easily available for extraction during brewing compared to green tea. While green tea leaves might start with high caffeine, differences in processing and brewing methods usually result in black tea having more caffeine in the cup. This is partly because black tea is often brewed with hotter water and for longer periods, which extracts more caffeine than the cooler, shorter steeps typically used for green tea.

Factors Influencing Caffeine Levels Beyond Tea Type

Multiple factors influence caffeine content, making it complex to say one type always has more than the other:

Tea Plant Varietal: The Camellia sinensis plant has varieties like assamica (higher caffeine, often used for black tea) and sinensis (lower caffeine, often used for green tea).
Harvest Time: Younger leaves and buds have more caffeine than older leaves.
Brewing Temperature: Hotter water extracts more caffeine. Black tea is usually brewed hotter than green tea.
Steeping Time: Longer steeping releases more caffeine.
Leaf Size and Form: Smaller, broken leaves (like in tea bags) extract caffeine faster due to a larger surface area.
Shade Growing: Teas like matcha and Gyokuro are shade-grown, increasing caffeine. Since matcha is consumed whole, its caffeine impact is significant.

Caffeine Comparison: Black Tea vs. Green Tea


Feature	Black Tea	Green Tea
Processing	Fully oxidized	Unoxidized (steamed/heated)
General Caffeine (8 oz)	40–70 mg	20–45 mg
Notable Exceptions	Varies by varietal (Assam vs. Darjeeling)	Matcha (shade-grown and powdered) often exceeds black tea's caffeine
Flavor Profile	Darker, more robust, and tannic	Lighter, more grassy or vegetal
Brewing Temp.	Higher (near boiling)	Lower (typically 160-180°F)
Brewing Time	Generally longer (3-5+ min)	Generally shorter (1-3 min)

Understanding the 'Caffeine Jitters' Effect

Green tea contains L-theanine, which works with caffeine to promote calm alertness, reducing the jitters sometimes associated with caffeine alone. Black tea has less L-theanine, contributing to a more immediate caffeine effect. This interaction makes tea's energy boost unique.

How to Adjust Caffeine Levels at Home

You can control caffeine in your tea by:

Adjusting Steeping Time: Shorter times release less caffeine.
Lowering Water Temperature: Cooler water extracts less caffeine.
Trying a Second Infusion: Subsequent brews have less caffeine.
Choosing Low-Caffeine Teas: Opt for varieties like Kukicha, Hojicha, or herbal options.
Using Loose Leaf: Whole leaves release caffeine more slowly than broken leaves in bags.

Conclusion

While black tea generally has more caffeine than green tea, this isn't always the case due to factors like plant variety, harvest, and brewing methods, especially water temperature and steep time. For a strong, consistent caffeine level, black tea is typical. However, high-quality green teas like matcha can offer a comparable or even higher caffeine content with a balanced energy effect thanks to L-theanine. Understanding these elements helps you choose the right tea for your desired caffeine level.

For a deeper look into the intricate science of tea and caffeine extraction, the American Chemical Society's article on the factors affecting the components of tea infusions is an authoritative resource: Factors Affecting the Caffeine and Polyphenol Contents of Tea Infusions.

Frequently Asked Questions

Yes, matcha green tea, which is shade-grown and consumed as a powder of the entire leaf, can contain a higher concentration of caffeine than an average cup of black tea.

To reduce caffeine in black tea, use cooler water and shorten your steeping time. A second infusion from the same leaves will also have significantly less caffeine.

Yes, there are two main varieties of Camellia sinensis. The assamica variety, often used for black teas, is naturally higher in caffeine than the sinensis variety, typically used for green teas.

Green tea contains L-theanine, an amino acid that works with caffeine to promote a state of calm alertness. This provides a more balanced energy boost without the jitters often associated with other caffeinated beverages.

Yes, steeping time is one of the most critical factors. The longer you steep tea leaves, the more caffeine is extracted. A longer steep can significantly increase the caffeine level.

True herbal teas (or tisanes) are not made from the Camellia sinensis plant and are naturally caffeine-free. However, some herbal infusions, like Yerba Mate, naturally contain caffeine.

Generally, tea bags contain smaller, broken leaves with a larger surface area, which can lead to faster and more efficient caffeine extraction compared to whole loose-leaf tea.