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How to Cold Brew Gyokuro: A Pure Umami Hit Unlike Any Other Tea

Cold brewing gyokuro means steeping 8 grams of leaves in 200ml of ice cold water for around 50 minutes. Because cold water barely extracts catechins, what you get is an unusually clean, sweet umami with almost no bitterness or astringency at all. It is lighter in body than the traditional 50°C hot brew, but delivers a purity of flavour that is unique to this method. The same leaves can then be used for two more hot infusions at progressively higher temperatures, each producing a noticeably different cup.
Behind The Leaves #30

Why Cold Water Changes Everything About Gyokuro

The logic behind cold brewing gyokuro is the same principle that makes the traditional 50°C hot brew work, taken to its logical extreme. Catechins, the compounds responsible for astringency and bitterness, extract most efficiently at higher temperatures. Cold water barely draws them out at all. What cold water does extract readily are the amino acids: L-theanine and the related umami compounds that define gyokuro's character. The result is a cup that is almost entirely built on sweetness and clean savoury depth, with none of the structural pull of catechins. As Yuki puts it, cold brewing maximises the strengths that make gyokuro unique.

The Setup and First Infusion

The recipe for the cold brew first infusion is 8 grams of gyokuro leaves to 200ml of ice cold water, left to steep for approximately 50 minutes. The same gyokuro used in the traditional hot brewing session was used here deliberately, so the two methods can be compared directly on the same tea.

After 50 minutes the leaves have opened fully, and the aroma coming off the pot already carries a clear lift of umami before the first pour. The liquid comes out a deep golden colour with a visible viscosity. Compared to the traditional 100ml hot brew, the cold brew is less thick because the greater water volume dilutes the extraction, and cold temperature itself slows extraction further. But compared to a standard cold-brewed sencha, it remains meaningfully thicker and more concentrated.


The dominant impression on tasting is sweetness. A pure, clean sweetness that is not typically present in Japanese tea to this degree. Umami follows, but it is soft and refined rather than the intense savoury punch of the traditional hot brew. There is virtually no astringency.

The Second Infusion: 60°C for One Minute

Once the cold brew is poured off, the residual ice is removed from the pot to avoid cooling the next infusion below the target temperature. The second infusion uses 100ml of water at 60°C, steeped for one minute.


The shift is immediately apparent in the aroma before the cup is even poured. The warmth is cooking the already-open leaves differently, releasing brighter, more vegetal notes that were entirely absent from the cold brew. The colour shifts from the deep golden of the first infusion to something slightly greener.

On tasting, the umami and sweetness are noticeably lower than the cold brew, and a mild astringency begins to appear, adding structure and texture.

 Vegetal notes become more prominent. It reads as a warm, heartwarming tea compared to the cold brew's refreshing clarity. The two infusions from the same leaves feel like entirely different drinks, which is part of what makes gyokuro a genuinely versatile tea.

The Third Infusion: 70°C for 30 Seconds

The third infusion steps up to 70°C and shortens the steep to 30 seconds. The colour is similar to the second infusion, perhaps marginally greener. The astringency and bitterness remain surprisingly low, which is a testament to how much of the catechin content was preserved through the cold and low-temperature first two infusions.


By this point, the characteristic thickness of gyokuro has largely gone. Umami and sweetness have faded significantly. What remains is a light, pleasant vegetal cup, smooth and easy to drink but a shadow of the intensity from infusion one. Still enjoyable, but clearly the final usable extraction from these leaves.

The Full Picture: One Set of Leaves, Three Completely Different Drinks

What this three-infusion session demonstrates is that gyokuro is not a single experience. The cold brew gives you maximum umami sweetness in a refreshing, light format. The 60°C second infusion gives you something warm and structured with vegetal character. The 70°C third infusion delivers a delicate final cup that acts as a gentle close. Using the same eight grams of leaves across all three, the value and range of expression from a single session is remarkable.

Key Takeaways

  • Cold brewing gyokuro is not a shortcut. It is a method that specifically isolates the tea's purest qualities. By using water near freezing, catechins barely extract, leaving a cup built almost entirely on umami and sweetness.

  • The sweetness in cold-brewed gyokuro is unusually prominent. It is not typically this present in Japanese tea, and it is unique to cold-brewing a tea as amino-acid-rich as gyokuro.

  • Cold-brewed gyokuro is lighter-bodied than the traditional hot brew, because the higher water volume and lower extraction temperature both reduce concentration. But it is still noticeably thicker than cold-brewed sencha.

  • Each successive hot infusion on the same leaves is a genuinely different experience. The 60°C second infusion is warm and vegetal. The 70°C third is light and fading. The progression is part of the method.

  • Remove residual ice before the second infusion. Leaving it in will drop the water temperature below your target and affect the extraction unpredictably.

Insights from Yuki

One key observation is that the sweetness in the cold brew was a genuine standout, described as something you simply do not encounter in normal Japanese tea at that intensity. It is a direct consequence of cold temperature suppressing catechin extraction while fully releasing amino acids.


This session used the exact same tea across all four brewing method videos in the series, specifically to enable direct comparison. The cold brew was noticeably less thick than the previous day's traditional hot brew at 100ml, which is expected given the doubled water volume and lower extraction efficiency at cold temperatures.


One key practical observation: residual ice left in the pot after the cold brew pour must be removed before the second infusion. Leaving it in would have unpredictably lowered the target brew temperature of 60°C, altering the extraction and making the comparison unreliable.
Q&A

How do you cold brew gyokuro?

Use 8 grams of gyokuro leaves in 200ml of ice cold water and steep for approximately 50 minutes. Pour to the last drop. The resulting liquid will be a golden, lightly viscous cup with clean umami sweetness and almost no astringency or bitterness.

Why does cold-brewed gyokuro taste sweeter than hot-brewed gyokuro?

Cold water extracts very little of the catechins that create astringency and bitterness, while still pulling out amino acids including L-theanine. With catechins largely absent, the sweetness and umami from the amino acids come through without any competing bitterness, making the sweetness more prominent than in any hot-brewed version.

Can you re-steep gyokuro after a cold brew?

Yes. After the cold brew, the leaves still hold significant compounds and can yield two more hot infusions. A second steep at 60°C for one minute produces a warm, vegetal, mildly astringent cup. A third at 70°C for 30 seconds gives a lighter, final extraction. Each infusion tastes noticeably different from the last.
About the author:

Yuki Ishii

Founder & CEO of Tealife

LinkedIn | YouTube

Yuki is the founder of Tealife, a Singapore-based Japanese tea company. He’s passionate about Japanese tea and spends his time testing, trying, and experimenting - then sharing what he learns through content to help people discover the depth of Japanese tea beyond just matcha.

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