Did you know that it isn’t necessary to use hot water to brew your tea?
Mizudashi (水出し) meaning “cold brewing” in Japanese is an easy way to brew your tea without heating the water at all.
Making your own iced tea
Since cold brewing takes some time, it’s best to brew many servings at once. I suggest that you brew a whole jar.
First, measure the volume of water that your jar can hold.
Update: Nowadays I like to use the total amount of water that a tea can make including all its infusions.
For example, when cold brewing a fukamushi sencha, I would use 240 ml (8 oz) and 4 grams of leaves. The reason is that this type of green tea can normally make 4 infusions of 60 ml (2 oz) each.
Feel free to find the ratio that works best for you.
Add the tea leaves to the jar and fill it up with water. Now all you need to do is place the jar in the refrigerator and leave it for 8 hours (overnight) or longer. Don’t worry, it won’t become bitter.
Finally, discard the tea leaves. You can now enjoy your iced tea, and it can last about two weeks if you keep it refrigerated (provided that you aren’t adding any sugar to it).
Why aren’t cold brewed teas bitter?
I wrote about it in my post about ice brewing gyokuro, but the short answer is that the main compounds responsible for astringency and bitterness (catechins and caffeine) aren’t very soluble at low temperatures.
Amino acids in the tea leaves, however, are soluble in cold water. So you can obtain the natural sweetness and umami taste of green tea.
What I like best about this brewing method is that no extra energy is used besides the electricity of the refrigerator, which would be operating anyway.
In my opinion, roasted green teas like houjicha and kyobancha are very good when iced. Genmaicha however, tastes better when hot.
Have you cold brewed your tea yet?
December 16, 2014
I’ve never cold brewed tea but I really want to do it one day. I’ve only hot brewed it and then cooled it down. I heard that the taste of cold brewed is much better.
December 16, 2014
Hello Kamyria
The taste of cold brewed tea is about the same, the good thing is that it doesn’t go bitter.
Nice tea blog by the way : )
December 16, 2014
Hola Ricardo,
My formula for sencha 水出し Mizudashi is 911. That is 9 grams of sencha, 1 litre of water, 1 overnight. Mizudashi really brings out another flavour in our lives! I had not given a thought about no extra energy being involved, but that is yet another plus point. Thanks for pointing this out.
December 16, 2014
Hola Lochan
I’ll have to try your 911 formula, it has a cool name!
Thanks for sharing it.
December 20, 2014
Hola Ricardo san,
In Japan this kind of cold brewing green tea in tea bag, specially for Sencha, is used for summer season and it’s very normal for Japanese people.
December 20, 2014
Hola Hide san
Yes, I’ve seen some Japanese tea bags that have the purpose of being cold brewed. I imagine that they have a type of tea that dissolves easily.
December 29, 2014
I’ve always made cold-brew with teabags because they are easy to remove and throw away. Ricardo, how do you remove the leaves when you make cold-brew from loose leaf?
December 29, 2014
Hi Noli
I use a sieve and transfer to another container, which in my case is a small pot. Then I pour the tea back in the jar.
As you say, it´s easier to use tea bags. But the leaves brewing inside the jar look great, and anyway I usually don´t have tea bags at home.
August 19, 2015
Hi Ricardo,
I didn’t know cold Japanese tea could be prepared this way before reading your post. I made my tea by cooling it down after boiling it. Will definitely try this method.Thanks for the post.
BTW how much green tea is good to consume in a day? In Japan I have seen people drinking from 1/2 litre bottles and personally don’t think there should be any problem. But do you think there is any downside of consuming large quantities of green tea in a day?
August 19, 2015
Sorry, I meant “1 or 2 litre” bottles and not “1/2” (half) litre.
August 19, 2015
Hi Abhijeet
Thanks for your comment.
For loose leaf tea there isn’t much downside of consuming large quantities, unless the caffeine starts to affect you.
October 30, 2018
Nice post. It’s warming up on Australia so cold brews will be perfect. Thanks for the suggestion on brewing hojicha cold.
October 30, 2018
Thank you for your comment Damien.
Enjoy your cold brewed tea.
May 17, 2020
Hi!
How long can I keep a cold brewed green tea in the fridge?
Kind regards, Ken
May 17, 2020
Hi Ken
I don’t have an exact answer for that. Some people say two weeks, some say one week. You can start seeing how the tea changes color (it oxidizes with time), or if the flavor changes.
Of course, if you sweeten it, it will last even less time.