Should matcha be foamy?

Most guides answer this question by telling you how to make more foam. That skips the question. Foam is not the goal of a bowl of tea, and in some schools of tea it is deliberately not complete.

Matcha does not have to be foamy. A fine, even foam is what I was taught to whisk in my own school, and it changes the texture rather than the flavor. Foam tells you about your whisking, not about the quality of the tea. If your bowl tastes thin, more foam will not fix it — more powder will.

What the foam actually is

Matcha is powdered leaf suspended in water, not an infusion. When the tines of the whisk move fast enough through that suspension, they pull air into it, and compounds in the leaf hold the bubbles long enough to form a layer. Nothing is added. The same powder, whisked slowly, gives you a flat green surface and tastes the same.

That is the part worth holding on to. The foam is made by your wrist, by the temperature of the water, and by whether the powder was sifted. It is not a grade, and it is not a verdict on the tea you bought.

Two surfaces, both correct

Walk into practice in two different schools and you will see two different bowls. In the school I practice in, thin tea is whisked until a fine foam covers the surface from rim to rim. In another, the surface is left partly open, and the crescent of liquid you can see at the edge is part of the look rather than a mistake. Both are thin tea. Both are correct in their own house.

If your bowl is in the last row, the fix is a separate subject and I have written it out in why matcha will not froth. This article is about whether you should be chasing foam at all.

What foam does to the drink

It changes the texture and the first impression. A bowl with fine foam feels rounder in the mouth, and the bitterness arrives a beat later because the air softens the front of the sip. Drink the same tea flat and you meet the bitterness immediately. Neither is wrong. On a hot afternoon I sometimes prefer the flat bowl, because it tastes sharper and more like leaf.

What foam cannot do is add flavor that is not there. Two scoops of powder, about 2 g, into 60 to 70 ml of water just off the boil, is the ratio I use. Whisk that badly and it still tastes like tea. Whisk a half-scoop into a full cup beautifully and it tastes like green water with a nice head on it. A bowl that tastes of nothing is nearly always a measuring problem, not a whisking one.

Cold foam is a different drink

The thick white-green layer on an iced matcha in a cafe is usually not matcha foam at all. It is cream or milk aerated separately, sometimes sweetened, then poured over the drink. It behaves differently, it lasts far longer, and it is made with a frother rather than a whisk. If that is the texture you want, you are looking for a milk technique, not a tea one. For what a frother can and cannot do to the tea itself, see the whisk and frother comparison.

Three things that change the foam more than the tea does

• Water temperature. Water just off the boil foams readily. Water left to cool to bath temperature will not, no matter how fast you move.
• Sifting. Matcha clumps in the tin. Clumps do not whisk into suspension, so they sit on the surface and break the foam. Pressing the powder through a small sieve takes ten seconds and is the single biggest change most people can make.
• The whisk itself. A hundred-prong chasen moves more water per stroke than a coarse one, and a splayed, tired whisk moves almost none. Mine is replaced when the tines lose their spring, which with daily use is a matter of months.

Foam does not wait. Within minutes it falls and the powder starts to settle, which is the main reason to drink a bowl as soon as it is made. More on that in can you leave matcha overnight.

What I do

I whisk to a fine, even foam, because that is how I was taught and because I like what it does to the first sip. But I do not treat the foam as the test of a good bowl. The test is the taste: sweet first, bitterness behind it, nothing chalky on the tongue. When I am teaching someone at my table, I have them make one bowl foamy and one bowl flat from the same tin, and drink them side by side. Most people are surprised by how small the flavor difference is — and that is the point of the exercise.

Questions I get asked

Should matcha be foamy?

It does not have to be. A fine foam is the finish in some schools of tea and a partly open surface is the finish in others. Foam changes texture, not flavor, so treat it as a preference rather than a standard.

Does foam mean the matcha is good quality?

No. Foam comes from your whisking, the water temperature and whether the powder was sifted. The same tin will foam beautifully or hardly at all depending on how you make it.

How much foam should a bowl of thin tea have?

Anywhere from a thin even layer to full coverage is normal. What matters more is that the foam is fine rather than made of large bubbles, because large bubbles collapse within half a minute and leave the surface patchy.

Why is my matcha foamy at the top but watery underneath?

That is usually too much water for the powder. Two scoops, about 2 g, to 60 to 70 ml is a reliable place to start. Whisking longer will not fix a ratio problem.

Is matcha cold foam the same thing?

No. Cafe cold foam is aerated milk or cream sitting on top of the drink, made with a frother. Matcha foam is air held in the tea itself and disappears within minutes.

Where this fits

If you are setting up at home, the two pieces that decide your foam are the whisk and the bowl: a wide chawan gives your wrist room to move, and the starter set puts the whisk, bowl and scoop together. The rest of the sequence, from measuring to drinking, is in the beginner's guide.

Written by Mio.K, who chooses everything in this shop by hand in Japan.