Does Green Tea or Earl Grey Have More Caffeine?

December 5, 2025 •

4 min read

A standard 8-ounce cup of brewed Earl Grey tea contains more caffeine than the same amount of green tea, typically with 40–70 mg compared to green tea's 20–45 mg. This difference is largely due to the variation in tea processing and oxidation, but the exact amount can be influenced by many factors.

Quick Summary

This article explores the caffeine content of green tea versus Earl Grey, detailing why black tea typically contains more. It explains the factors influencing caffeine levels, from processing to brewing methods, and provides a comparative look at the health benefits of both teas.

Key Points

Processing is Key: Earl Grey, a black tea, is fully oxidized, allowing for greater caffeine extraction during brewing compared to unoxidized green tea.
Earl Grey is More Caffeinated: An 8-ounce cup of Earl Grey typically contains 40–70 mg of caffeine, while green tea has 20–45 mg.
Brewing Affects Potency: Steeping for longer and using hotter water will increase the caffeine content in both teas.
Matcha is an Exception: Powdered green tea like Matcha can have a much higher caffeine content than regular green or black tea because you consume the whole leaf.
L-Theanine Provides Calm Focus: Green tea contains more L-theanine, which promotes a state of relaxed alertness and can mitigate the jittery effects of caffeine.
Choose Your Energy: Pick Earl Grey for a stronger energy boost and green tea for a milder, more focused lift.

Why Earl Grey Typically Has More Caffeine

All true tea types—white, green, oolong, and black—come from the Camellia sinensis plant and inherently contain caffeine. However, the variation in processing methods and oxidation is the primary reason for the difference in caffeine content between green and Earl Grey teas. Green tea leaves are quickly steamed or pan-fired to prevent oxidation, preserving their natural green color and lower caffeine levels. In contrast, Earl Grey is a flavored black tea, and black teas undergo a complete oxidation process where the leaves are exposed to air after being rolled or crushed. This extensive oxidation breaks down the plant's cell walls, making more caffeine available for extraction during brewing.

The Impact of Processing on Caffeine

During production, black tea leaves are fully oxidized, a process that creates their distinct dark color and robust flavor. This processing makes the caffeine within the leaf more readily accessible when steeped in hot water. Green tea, by forgoing this oxidation step, retains more of its original leaf structure. This results in a less permeable leaf, meaning less caffeine is released into the water during a standard brewing time.

Factors That Influence Caffeine Content in Your Cup

While the type of tea is a major factor, the final caffeine amount in your mug is also determined by several other variables. Understanding these can help you better manage your caffeine intake.

Brewing Time: Steeping tea for a longer period extracts more caffeine from the leaves. For example, a quick 1–2 minute steep of Earl Grey will yield less caffeine than a 5-minute steep. The same is true for green tea, though its caffeine release is slower overall.
Water Temperature: The hotter the water, the more efficiently it extracts caffeine and other compounds from the tea leaves. Since Earl Grey (black tea) is typically brewed with hotter water than green tea, more caffeine is released, adding to its higher content.
Leaf Size and Grade: The size of the tea leaves plays a significant role. Teas with smaller, broken leaves, often found in teabags, release their caffeine and flavor more quickly and intensely than larger, whole leaves.
Cultivar: The variety of the Camellia sinensis plant used also affects caffeine levels. For instance, the assamica varietal, common in many black teas, is naturally higher in caffeine than the sinensis varietal typically used for many green teas.
Matcha Exception: An important exception to the rule is Matcha, a powdered form of shade-grown green tea. With Matcha, you consume the entire tea leaf, not just the infusion. This means a serving of Matcha can contain significantly more caffeine than a cup of regular black tea, including Earl Grey.

Green Tea vs. Earl Grey: A Comparison


Feature	Green Tea	Earl Grey Tea
Tea Base	Steamed or pan-fired Camellia sinensis leaves.	Black tea (fully oxidized Camellia sinensis leaves).
Average Caffeine	20–45 mg per 8 oz cup.	40–70 mg per 8 oz cup.
Oxidation Level	Unoxidized.	Fully oxidized.
Key Antioxidant	Primarily catechins, notably EGCG.	Theaflavins and thearubigins (created during oxidation).
Key Amino Acid	High in L-theanine, promoting calm alertness.	Also contains L-theanine, but in lower concentrations compared to green tea.
Distinct Flavor	Grassy, earthy, or vegetal.	Bold, malty black tea with citrus notes from bergamot oil.
Common Benefits	Rich in antioxidants, brain health support, potential metabolic boost.	Supports heart health (cholesterol, inflammation), aids digestion.

Making the Right Choice for Your Needs

Choosing between green tea and Earl Grey depends on your personal preferences and energy needs. If you require a more significant and immediate energy boost, Earl Grey is the more reliable choice due to its higher average caffeine content. The stimulating effect is pronounced, making it a popular morning beverage. On the other hand, if you prefer a gentler, more sustained lift without the potential jitters, green tea is the better option. The high L-theanine content in green tea interacts with caffeine to promote a state of calm alertness, making it ideal for focus and concentration.

Both teas offer unique health benefits, primarily from their antioxidant properties. Earl Grey's black tea base is rich in antioxidants that support heart health, while green tea's catechins are noted for their anti-inflammatory effects and brain health support.

Conclusion

While the specific caffeine content can vary based on brewing methods, the tea's origin, and processing, Earl Grey generally has more caffeine than green tea due to its full oxidation. Earl Grey provides a more potent and faster caffeine delivery, whereas green tea offers a milder, more sustained energy lift complemented by its relaxing amino acid L-theanine. Therefore, if a stronger, more intense kick is what you're after, reach for the Earl Grey. For a calm, focused boost, green tea is your best bet.

For more detailed information on factors influencing caffeine levels in tea, refer to the comprehensive guide by ArtfulTea.

Frequently Asked Questions

The main reason is the difference in processing. Earl Grey is a type of black tea, which undergoes a full oxidation process. This process breaks down the tea leaves, making more caffeine available for extraction when you brew it with hot water, unlike green tea, which is unoxidized.

Yes, in specific cases, such as Matcha green tea. Because Matcha is made from powdered, shade-grown green tea leaves where you consume the entire leaf, a serving can contain significantly more caffeine than a cup of regular Earl Grey.

Longer brewing times and higher water temperatures extract more caffeine from the tea leaves. Brewing Earl Grey with near-boiling water for several minutes will yield a much higher caffeine content than steeping green tea with cooler water for a shorter period.

Yes, L-theanine in green tea works with caffeine to create a unique effect. It promotes a state of calm alertness and focus, reducing the jitters often associated with high caffeine intake, which is one reason green tea's energy boost feels different from Earl Grey's.

Both teas offer health benefits. Earl Grey's black tea base contains antioxidants that support heart health by potentially reducing bad cholesterol. Its distinct bergamot oil also has anti-inflammatory properties.

If you want less caffeine, green tea is the better choice on average. For an even lower-caffeine option, you can shorten your steeping time or opt for white tea, which is typically the least caffeinated of the true teas.

No, the bergamot oil added to flavor Earl Grey does not contain caffeine. The caffeine in Earl Grey comes solely from the black tea leaves used as its base.