I’ve received questions by readers regarding the foam of matcha.
First of all I must warn that some schools of the Japanese tea ceremony prefer less foam or not at all, so it’s basically an aesthetic thing.
Also, I don’t think that a matcha that froths easily always tastes better.
The foam that you see on top of a whisked matcha occurs because of a compound called saponin. Some matchas have a higher saponin content than others.
These are the 4 reasons why your matcha isn’t frothing:
1. Not sifting your matcha
Sifted matcha is easier to dissolve in water.
While I personally don’t sift my matcha at home every time, it does make a difference regarding the resulting foam.
2. The water isn’t hot enough
Cold water results in many lumps, and hence less foam.
80 °C (176 °F) water is recommended, but you can use hotter water, even boiling.
When preparing loose leaf green tea, high temperature can be a problem because you may extract too much catechins and the tea becomes very bitter and astringent.
In matcha, however, the powder will dissolve completely. So you can definitely use boiling water, but a lower temperature is recommended because a very hot matcha is harder to drink.
For a hot matcha one has to wait until it cools down, otherwise you’ll burn your tongue and won’t be able to taste it well 🙂
3. The matcha to water ratio is too low
Using too few matcha powder and too much water makes for a weak matcha. It’s obviously harder to froth.
People that prepare matcha for the first time often think that they have to fill the entire matcha bowl. You don’t need to, it would be too much matcha.
The reason the matcha bowl is big is because it allows the whisk to fit, and so that it won’t spill while whisking.
You only need 60 to 70 ml (2 to 2.3 oz) of water, it’s about a fourth of my matcha bowl, but it depends on the bowl.
Regarding the matcha, 2 grams is usually recommended. That’s roughly about 2 scoops of the tea scoop (chashaku), or one teaspoon.
However, when I weight the matcha that I use, it often ends up being about 1.6 – 1.8 grams. It doesn’t have to be exact.
4. Whisking skill isn’t good enough
I have to admit that I’m not very good at whisking. I must practice more.
If it’s your first time whisking matcha with the tea whisk (chasen), don’t expect a nice foam.
As with many things in life, you’ll get better eventually if you keep doing it.
Matcha frothing experiment
I prepared two matchas using the same ceremonial grade powder. The idea is for you to see the results in the foam with different parameters.
For the picture at the top of this post, the water was at 80 °C (176 °F), I used 2 grams of matcha which I didn’t sift, and 100 ml (3.3 oz) of water.
For the picture at the right, I sifted the matcha, the water was near the boiling point, and there were 2 grams of matcha with 60 ml (2 oz) of water.
As you can see, the first matcha has less foam and big, course bubbles. It doesn’t look good.
In the second attempt, the layer of foam is more uniform and the bubbles are smaller. This one also tastes better than the other one, mainly because the matcha to water ratio is correct.
There’s another thing that I haven’t mentioned. At first whisk your matcha with a little bit of water and then add the rest of the water. This way you’ll have less lumps of matcha.
Again, depending on the school of the tea ceremony too much foam may be undesirable.
But for a good looking matcha prepared in a casual way, keep this four points in mind.
August 4, 2015
Good job! It’s easy to understand that I keep them in mind.
August 4, 2015
Thank you Wataru, enjoy your frothy matcha.
August 4, 2015
Hi Ricardo,
Matcha powder do not dissolve in water. It will settle out of suspension after some time.
It is definitely a matter of taste, but my experience tells me that the brewing temperature influences the intensity of taste perception of tart, bitter and sour, not sweet.
The intensity of “tart” is longer and more intensively at warm temperatures.
The taste of bitter is stronger at low temperatures but brewed at hot temperatures it lasts longer.
Therefore I like to prepare my bowl of Usucha at lower temperatures.
August 4, 2015
Hi Oca
Thank you for your comment. You’re right, I looked it up and it stays suspended. The goal is to have less matcha lumps in the water, I don’t know what the technical term would be.
Yes, things taste differently depending on temperature. I also prepare my usucha at a lower temperature, the boiling water was used as an experiment. Anyway you can let it cool down before drinking.
August 4, 2015
Oh, and about the temperature, from what two Japanese tea instructors told me and what I commonly see in matcha recipes, the higher temperature does help in mixing, but if it’s not dissolving then in must be some other thing that happens.
The saponins that are said to be the source of foam in matcha have a fat-soluble part and a water-soluble part. I think that some compounds in matcha do dissolve in water, the same as what happens with loose leaf tea.
August 4, 2015
Hi Ricardo,
This is very timely for me as I have been struggling to get proper foam in my matcha. I also found that, all things being equal, some matcha foam much better than others. Maybe the quality of the matcha itself also explains part of this problem of foaming. That I suppose is related to your saponin argument.
Anyway, this is a great post and I think I need to note down the points including those in various replies to you. Thank you once again.
August 5, 2015
Hi Lochan
Some matcha definitely foam better than others. I have a culinary grade matcha that foams very quickly, while a ceremonial one I have is hard to froth, although the quality is superior. In some time I will share the review of that matcha in this blog.
August 5, 2015
Hi Ricardo,
Thank you for this very clear and consise explanation and pointing out of some very concrete points of attention when it comes to whisking matcha.
Having given a ton of “how to whisk matcha” workshops over the past few weeks, I came across a few additional discoveries which I would like to add to your “4 point guideline”.
1. Not sifting your matcha.
It is mostly because of static electricity that matcha sticks together. You can release this tension by sifting the matcha and allowing space and air in between the grains.
2. The water isn’t hot enough.
When your whisking technique isn’t good enough and you aren’t able to create a sufficient amount of foam, the answer is not to whisk longer. The longer you whisk, the more you will cool down the tea and the less likely you will be able to create a beautiful froth.
The trick is to whip-up a good foam in a matter of seconds and then cleaning up the surface, breaking up larger bubbles to form a more minute foam.
3. Balance
I have nothing to add to this as this is very basic. Find the right balance between water and matcha powder.
4. Skill
Practice is key; a good teacher is gold. Once you learn how to ride a bike, you will remember forever.
One additional tip I can give.
Don’t cool your water. Pour it in at 90℃ right after it has boiled. It will cool down instantly when it hits the bowl and more when you start whisking.
Apologies for my boldness.
Tyas
August 5, 2015
Hi Tyas
Thank you for your detailed answer, I especially liked what you say about whisking too long.
Why do you think that hot water helps? I believe that the water-soluble components in matcha dissolve easier in hot water, just like in loose leaf tea, and the reason that there are sediments that settle, is because some of the non-soluble components remain.
August 5, 2015
Ricardo,
I am not much of a scientist when it comes to explaining why certain components do things, whilst other components do otherwise.
You may have a point there with your explanation which appears very plausible to me.
I find it interesting that you mention saponins as the source of matcha foam. I understand saponin as the base for what is called “egumi” in Japanese, which translates as a “disturbing taste”, something I wouldn’t want to have too much of in my tea.
I think it is a very interesting question and something I should look into more myself as well. Why does hotter water result in a better foam? Could it have to do with the movement of CO2 in the hot water; or does it relate to the release of soluble components as Ricardo indicated?
Tyas
August 6, 2015
I just saw in the Nihoncha Instructor book that saponin has an unpleasant taste. Perhaps a matcha that has too much saponin froths very easily but doesn’t taste as good.
August 6, 2015
Definitely going to have to share this post. I get this question often as well! Sometimes I have incredible foam, some days it’s not my best work. I can’t wait until I can master the art of whisking! 🙂
August 6, 2015
Thanks for sharing Lu Ann.
I’m also in the process of mastering the art of whisking!
July 24, 2016
I don’t know much about tea, but I do know a thing or two about food science. There is protein in matcha tea, and protein breaks down and can reform bonds at high temperate (or high acidity) with manipulation (in this case whisking). This could be an explanation for why it is much easier to create a foam when the water is hotter.
July 24, 2016
Dear Bianca
Thank you for your comment. Matcha does have protein, but it’s a very small amount. Please take a look at my post about saponin.
February 25, 2018
Very helpful post, and the comments are also helpful.
February 25, 2018
Thank you Bonnie.
I hope that you find many helpful posts in this blog 🙂
July 16, 2019
Not sure what grade matcha I have, but I do struggle with bitter taste. This time I whisked it for a long time, first getting huge bubbles that I managed to size down with the whisk.
Do you think having too cold water might be the culprit? I might have let my water cool down for too long.
I read in the comments that you recommend pouring water at 90˚C.
Also, I tried whisking in a bowl for a change, but maybe it was too big?
July 16, 2019
Hi Grus, thanks for your comment.
If it’s too bitter, it could be of low quality or you’re not used to matcha yet. Try adding more water once it froths, the taste will be lighter.
A bigger bowl is better than a smaller one, because you have more space to whisk.
The higher the temperature, the easier it froths.
Other than that, it’s a matter of practice.
November 8, 2020
It is very unfortunate for you to share this way without understanding. Higher temperatures for any unprocessed green tea will kill the major benefits of the tea and most especially matcha because of how fine it is. Anything over 85 celsius is undesirable as many of the polyphenols will be destroyed, particularly EGCG. The polyphenol catechins are also what is astringent so people will experience this as a bitter flavor, and higher temperatures also bring those out.
https://www.sciencedirect.com/science/article/abs/pii/S0260877419300305
https://www.tandfonline.com/doi/full/10.1080/10942912.2014.983605
“Although tea polyphenols possess a variety of biological activities, the oxidative stability of tea polyphenols limits its application in the diet as preventive medicine. With increase of temperature, the tea polyphenol solutions became darker and less green, but deeper yellow in color. When the heating temperature was 100°C, a significant reduction in both total catechins and transmittance was observed.”
Also, matcha doesn’t dissolve, it is suspended. There is nothing soluble. The sediment is simply unsuspended tea that drops to the bottom. That is due to static electricity from not being sifted well and particles naturally coming back together in whisking. If you whisk the tea and leave it sitting, almost all of it will eventually be on the bottom.
Finally, within a certain range, it is precisely the opposite as you report. Foam is easier in cooler liquids, thought of course not too cool. It is created by oxygenation from the rapid movement of a whisk. If the water is too hot, it is de-oxygenated via off-gassing and will produce less foam because the oxygen stretches the saponin structure to form the foam. Even iced matcha foams by shaking vigorously.
Ratio of tea to water, poor whisk, too fast or slow whisking are the major issues of foam. Anyone that wants to do themselves a favor, buy a milk frothing wand, learn what it tastes like best for you when correctly frothed, and then learn bamboo whisking to match.
November 8, 2020
Even the Nihoncha Instructor Association recommends boiling water for some green teas, for example bancha. The focus of tea is mainly aroma and flavor. You can definitely prepare matcha iced, but in my experience it tastes sort of flat and the aroma isn’t as good as if it was warm water.
Very high quality matcha will not be bitter nor astringent even in boiling water. If it is a lower quality matcha, then yes, it will be less bitter at lower temperature water.
Finally, the different between a high quality matcha and a lower quality one in terms of chemistry, is the amount of amino acid content. The catechin content is not an indication of quality, which goes back to the point that what we are looking for is taste above health, similar to the case with wine or whisky. If you only want the healthy part, you can buy green tea extract with plenty of EGCG as a supplement.
November 16, 2020
This is your site Ricardo, so I hope you receive this with respect and friendly teasing out of nuance.
First, above I wrote “there is nothing soluble” which is not accurate. I meant to say that the boiling of extracts the soluble and what remains is suspended. Matcha is a whole leaf extraction-suspension. Different than non-powdered which is most desirable as extraction only
Yes, for some tea it may be appropriate to boil, For ones that boiling will burn, you boil then allow it to cool to proper temperature via pouring or better yet, standing. Reaching boiling allows for softening the water, which is one thing not mentioned and is quite a commonly overlooked factor for what may be affecting foam production. Many municipalities have hard water.
It is also chemistry that dictates that the property of things change according to not only temperature but size and time. Tea solubles such as theanine are extracted, so the more surface area, the more rapidly that occurs regardless of the quality. While theanine and caffeine are the most significant contributor to the taste of tea, the catechins contribute to the bitter taste, which you pointed out in your instruction. Because the catechins are the most proliferate in tea, and are so impacted by temp, the temperature is critical for balancing.
To wit, I have a high amino acid (theanine and GABA) matcha and there’s a good deal of sweet but it’s somewhat flat without the astringency.
People will naturally do what they like and it seems as one is learning to appreciate matcha, it’s a good idea to not sacrifice taste for foam just as much as not sacrificing it for health (though I do have the gaba-dense tea for just that reason.)
My point was less about retaining the health value, though that is useful to know and many people turn to green tea in particular increasingly for health, and also not about ice matcha — that refers to temperature being not related to foam but extraction through agitation. What is important for taste is that reduction of temperature impedes the extraction of catechins, thus bitterness.
Last, because saponin is the culprit of better foam at higher temperature, but as I believe someone said, also more bitterness hence the need for temperature balance.
We cannot extract the sweetness of theanine without also drawing the bitterness of both catechins and saponin.