Cold green tea – mizudashi (水出し, “cold steeping”) – is the Japanese way of brewing green tea with cold instead of hot water. The result is called reicha (冷茶, “cold green tea”): mild, sweet, barely bitter – and on hot days more refreshing than any warm cup.
Key points at a glance
- With mizudashi, the tea leaves steep in cold water (8–10 °C) instead of hot – this lets the sweet amino acid L-theanine dissolve well, while bitter tannins (catechins) and part of the caffeine stay in the leaves.
- Basic recipe: 15–25 g of loose-leaf tea (approx. 3–4 heaped tsp) to 0.5–1 liter of cold water, steeped in the fridge for about 1 hour.
- Almost all varieties are suitable – sencha, bancha, hojicha, gyokuro. The exception: Benifuuki, which can develop undesirable substances with long steeping times.
- According to studies, cold-brewed green tea provides more EGC and amino acids, but less EGCG (only about half per cup) than hot tea.
- Reicha keeps refrigerated for up to 24 hours and stays fresh and green longer than hot tea that has been cooled down.
It's not just cold matcha – cold green tea is also worth it on hot summer days. Unlike our article Cold matcha – how it works, this one isn't about recipes, but about the traditional preparation method mizudashi – and what happens in the glass.
What are mizudashi and reicha?
Translated from Japanese, mizudashi means “cold steeping”. The finished drink is called reicha (冷茶), which simply means “cold green tea”. The core of the method: the water is cold from the very start. The tea is never brewed with hot water and then cooled down – this difference determines the flavor and the compounds in the cup.
The reason lies in solubility: bitter tannins and caffeine dissolve mainly in hot water. At low temperatures they largely stay in the leaf, while the sweet, umami-rich amino acid L-theanine passes readily into the cold water. That's why reicha tastes soft and naturally sweet rather than bitter, even after a long steeping time.
Which tea is suitable for mizudashi?
There is no fixed rule for cold preparation – from bancha and sencha to hojicha, gyokuro and tencha, almost any variety can be cold-brewed. Sencha works particularly well: cold water brings its amino acid sweetness and umami to the fore and holds back the astringency.
One exception is Benifuuki: if steeped for too long, this tea can develop undesirable, phototoxic substances and is therefore not suitable for long cold steeping.
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What sets special mizudashi teas apart?
With specially labeled mizudashi teas, the leaves come from early pickings (1st harvest) and are processed with a high degree of steaming. The entire process is shorter than for regular senchas or banchas.
This processing opens up the leaf surface so that the compounds pass evenly into the cold water and develop their full aroma. To tell them apart, such teas carry the addition mizudashi in their name.
How do I make cold green tea?
The preparation couldn't be simpler and works without any special equipment. All you need is loose-leaf tea, cold water and a carafe or a mizudashi glass bottle.
Add the tea
Put 15–25 g of loose-leaf tea (approx. 3–4 heaped teaspoons) into a carafe or mizudashi bottle.
Pour cold water
Pour 0.5–1 liter of cold water over it.
Let it steep
Place in the fridge for about 1 hour; the ideal steeping temperature is 8–10 °C.
Strain & enjoy
Drink right away or within 24 hours – after that, the flavor fades.
Avoid steeping times of more than 6 hours. As a general rule: the longer the tea steeps, the more caffeine and catechins dissolve. You'll find more about steeping times for warm green teas in our article Steeping times for green tea – everything at a glance.
What are the advantages of cold green tea?
In Japan, mizudashi is very popular on hot summer days; here it is still something of an insider tip. Reicha is ideal especially for getting started with green tea: few bitter compounds, a mild character and refreshing, sweet aromas that delight umami fans in particular. The simple preparation is also practical, and it's easy to take along on a trip to the lake or a hike.
The compounds shift, too. According to research, cold-brewed green tea contains significantly more free amino acids such as L-theanine. As for the ratio of EGCG (epigallocatechin gallate) to EGC (epigallocatechin), the more heat-sensitive EGC dissolves better at low temperatures – reicha therefore tends to be richer in EGC but poorer in EGCG (cold water dissolves only about 50% of the EGCG per cup). Studies (including Monobe et al., JIRCAS) suggest that EGC may have an immunostimulating effect; however, no reliable health claims can be derived from this yet.
Cold or warm green tea – which is better?
Both have their place – the following overview shows the differences at a glance.
|
Feature |
Cold (mizudashi) |
Warm |
|
Flavor |
Mild, sweet, lots of umami |
Stronger, more astringent |
|
Bitter compounds |
Few – even with long steeping |
Significantly more |
|
L-theanine |
High |
Lower |
|
EGCG |
Lower (approx. half as much) |
Higher |
|
Shelf life |
Refrigerated up to ~24 hours |
Best fresh |
|
Best occasion |
Hot days, on the go |
Relaxation, cooler days |
Warm green tea can promote a feeling of relaxation and support digestion, while cold tea is refreshing on hot days and keeps longer. In the end, your taste and the situation decide.
Conclusion
Mizudashi is the easiest way to rediscover green tea: cold water, an hour of patience, a mild and sweet result. If you shy away from the astringency of warm infusions or are looking for a refreshing summer tea, reicha is the perfect alternative.
