Sencha quality and foam, anyone heard this?

[Xell]

I saw recently someone saying, that the more foam when brewing sencha, the better it is, kind of indication of quality. Does anyone know about this something? Just trying to figure out where this came from. When i prepare tea i try to pour water as gently as possible and usually i don't see any foam.

[chado.my.teaway]

Year ago a I heard something like this. I dont know what thinking about that. I can see the foam in oolong and black tea brew. And sometimes in green.

I heard that the foam provides a good-brewed tea, not quality.
There's no denying that the more a firm stream of water, the more foam.

I hope you understand me;)

[Kevangogh]

The amount of foam has a lot to do with the water and how it was heated. If you try to use microwaved water you'll get almost no foam.

[Chip]

I never noticed "foam" before, but yesterday there was a decent amount of foam or bubbles in my kyusu as I brewed.

Not sure otherwise what you may be referring to Xell?

[Xell]

Because several people mentioned foam i got interested why it appears and why they talked about it being related to quality. Today i got "Kinetics and equilibria of tea infusion. Part 11 The kinetics of the
formation of tea scum" by Michael Spiro & Deogratius Jaganyi. Didn't read yet, but seems it's not as simple, as just how water was heated.

[Xell]

As far as i understand, foam in tea has a lot to do with saponins contained in leafs. Here's a photo of what i meant (not mine). Though didn't search on why some teas have more and some teas have less and how it affects the taste, but they idea actually got interesting, might return to it later

[Stentor]

I think even if there was something to it (which I doubt), foam would be a poor indicator of quality of leaf. Can't you just get similar kinds of bubbles (or "foam") by pouring the water/tea from an elevated position so that it hits the liquid that's already in the cup very hard, causing air bubbles to form?
It seems hard to differentiate between the possible cause for this "foam".
I don't think you can get a lot of foam/bubbles if you pour very gently.
But please, convince me otherwise

[Tead Off]

I only want foam in my matcha, please.

[Xell]

I think even if there was something to it (which I doubt), foam would be a poor indicator of quality of leaf. Can't you just get similar kinds of bubbles (or "foam") by pouring the water/tea from an elevated position so that it hits the liquid that's already in the cup very hard, causing air bubbles to form?
It seems hard to differentiate between the possible cause for this "foam".
I don't think you can get a lot of foam/bubbles if you pour very gently.
But please, convince me otherwise

Inside kyusu i won't pour from high height, i think it's wrong to do, but i saw some videos of tea-masters pouring from kyusu to cup from quite a height. Depends on how much saponins are contained in tea, foam can vary. So i wonder, if tea with more or less "foam" have something in common. Somehow i feel like there is nothing to it, but going to try and see if pouring into cup from longer distance changes taste or not.

[JRS22]

It's quite a relief to learn that the bit of foam I see around the edges of the cup aren't from sloppy rinsing!

[Seeker]

I think I can clear this up -
stop using your chasen with your sencha!
Chasen is for use with matcha only.

[Chip]

Pouring from height can help to cool a tea ... I will occasionally do this if I am pouring into a pitcher or a larger yunomi ... and I want the tea cooled a bit. (plus sometimes it is a bit fun ... )

I do notice now that as I pour from vessel to vessel to cool the water before brewing, any bubbles that form disappear very quickly. However bubbles in my kyusu as I am brewing, remain. I would have thought this had something to do with the increasing viscosity ... and maybe air released or displaced by dry leaves absorbing water.

[Kevangogh]

You can get foam from the very same batch of tea leaf that gave no foam on a different infusion five minutes prior. It depends on how you heat the water.

[chingwa]

I don't normally have foam in my kyusu... at least, not that I've noticed.... have a I been making my tea "wrong" all these years? now I'm starting to wonder...

[Kevangogh]

From my observations, I think it tastes better with a bit of foam, I aim for that.