The Impact of Water Temperature on Green Tea

by Sugimoto Tea Company
Tea Guides, Sugimoto Tea News


Brewing the perfect cup of green tea is both an art and a science. It is influenced by various factors such as the quality of the tea leaves, water quality, steeping time, and, crucially, water temperature. Each of these elements plays a significant role in extracting the flavors and naturally occurring compounds that make green tea both enjoyable and beneficial. For a deeper dive into the impact of water quality, you can refer to our blog on The Impact of Water Quality on Your Japanese Green Tea. In this blog, we will explore how water temperature specifically impacts the flavor and caffeine content of brewed green tea.

The Science Behind Brewing Green Tea

Green tea is rich in various compounds, including catechins (a type of antioxidant), amino acids, and caffeine. The solubility of these compounds varies depending on the water temperature, which means the temperature at which you brew your tea can significantly influence its taste and the balance of its components.

  • Catechins contribute to the tea's astringency and bitterness.
  • Amino acids like theanine add a sweet, umami flavor.
  • Caffeine provides the stimulating effect that many tea drinkers seek.

Factors Affecting Caffeine Extraction

Green tea naturally contains caffeine, although the amount can vary widely depending on the type of tea and brewing method. Water temperature plays a crucial role in caffeine extraction:

  • Lower temperatures (130°F to 140°F): Extract less caffeine, resulting in a milder, less stimulating cup of tea.
  • Medium temperatures (160°F to 175°F): Offer a balanced extraction, drawing out moderate levels of caffeine along with a harmonious blend of catechins and amino acids.
  • High temperatures (195°C to 212°F): Extract the most caffeine, resulting in a stronger, more astringent tea.

The chart below illustrates the caffeine content in different types of green tea based on various brewing methods and temperatures:


mg caffeine/ serving


mg caffeine/ serving


mg caffeine/ serving


Sencha Fukamushi




5g (2 tsp) Leaf, 12 oz (350ml) Water @175°F, 45 sec





5g (1 Tbsp) Leaf, 12 oz (350ml) Water @180°F, 45 sec





5g (1 Tbsp) Leaf, 12 oz (350ml) Water @180°F, 1.5 min





3g (1 Tbsp) Leaf, 12 oz (350ml) Water @200°F, 1.5 min





5g (2 tsp) Leaf, 6 oz (180ml) Water @130°F, 3.5 min





5g (2 tsp) Leaf, 6 oz (180ml) Water @130°F, 3.5 min

*Boiling Water Method: 5g Leaf, 12 oz (350ml) Water @212°F, 3 min
**Cold Brew Method: 5g Leaf, 12 oz (350ml) Water @40°F, 15 min

Additionally, this chart shows how caffeine extraction rates change with different steeping times and water temperatures:

For more detailed information on caffeine content in green tea, please refer to our blog post on How Much Caffeine Is In Green Tea?

Brewing Recommendations for Different Types of Tea

Different types of green tea require different brewing temperatures to achieve their optimal flavor and caffeine balance:

  • Gyokuro: Brew at low temperatures (130°F to 140°F). This delicate tea benefits from a gentle extraction, highlighting its sweet and umami flavors while keeping caffeine levels low. This is generally the same rule of thumb for other shaded teas, such as Kabusecha as well.
  • Sencha: Brew at medium temperatures (160°F to 175°F). This versatile tea strikes a balance between the astringency of catechins and the sweetness of amino acids.
  • Hojicha: Brew at high temperatures (195°C to 212°F). The roasting process of hojicha reduces its caffeine content, making it suitable for high-temperature brewing that brings out its rich, toasty flavor.

What is the Difference Between Cold Brew Tea and Iced Tea?

Cold brew tea is a unique method that differs from iced tea. While iced tea is brewed hot and then cooled with ice, cold brew tea is steeped in cold water from the start, typically for an extended period. This method results in a slower and more extraction process, leading to a distinct flavor profile.

Benefits of Cold Brew Tea

Cold brewing green tea results in significantly lower caffeine content, making it ideal for those sensitive to caffeine or seeking a more moderate effect. The slow extraction process also produces a smoother, milder flavor, as fewer tannins are released overall, reducing bitterness and astringency. This method is particularly refreshing and convenient for hot weather, providing a crisp, clean taste without the need for cooling down after brewing. Cold brew tea is perfect for staying hydrated and can be easily personalized with fruits, herbs, and other fresh botanicals for a variety of delicious, refreshing drinks.

Key Takeaways

Water temperature is a critical factor in brewing green tea, affecting everything from flavor to caffeine content. By understanding how different temperatures influence the extraction of various compounds, you can tailor your brewing process to match your personal preferences. Whether you enjoy the delicate sweetness of gyokuro or the robust taste of hojicha, experimenting with water temperature can help you discover your perfect cup of tea.

Remember, the best brewing method is the one that suits your taste. Don’t hesitate to experiment and find the ideal conditions that make your tea experience truly enjoyable.

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