Gongfu- bubble scraping... how come?

[zacstill]

A simple question that I'm sure will result in more than one answer.

Why is it recommended that you fill the put up to the top, then scrape the bubbles away with the lid before putting it back on when making gongfu tea?
I don't see how the bubbles could dramatically affect the taste...

[tenuki]

next time you brew scrape off and taste the bubbles.

[taitea]

I've been wondering about this myself for a while now. I will definitely try tasting the bubbles next time.

It seems to me that certain teas gives off more bubbles/foam. Yancha in particular. Has anyone else noticed this? Any explanations?

[orguz]

I have wondered about the foam/bubbles, personally I haven't brewed indian teas and japanese teas. Can anyone comment on whether these teas also produce similar foam/bubbles?

A local chinese radio personality/tea expert once said that it was the pesticides in chinese teas that caused this, no foam/bubbles were detected with indian, sri lankan teas, can any teadrinkers verify this?

Thanks

[beecrofter]

A local chinese radio personality/tea expert once said that it was the pesticides in chinese teas that caused this, no foam/bubbles were detected with indian, sri lankan teas, can any teadrinkers verify this?

Thanks

I was once told that the moon was green cheese, rabbits only ran uphill, and onions were skunk eggs.

[Salsero]

I was once told that the moon was green cheese, rabbits only ran uphill, and onions were skunk eggs.

This is startling news indeed!

As for bubbles, I have never really noticed any!

[t4texas]

Yet another mystery. I was recently wondering why scraping off the bubbles is advised. I do see the bubbles - usually scrape, but sometimes not.

[wyardley]

Imen's take from a while back:
http://tea-obsession.blogspot.com/2008/03/bubbles.html

makes sense to me.

[betta]

A local chinese radio personality/tea expert once said that it was the pesticides in chinese teas that caused this, no foam/bubbles were detected with indian, sri lankan teas, can any teadrinkers verify this?

Thanks

The bubbles appear when air is trapped inside a liquid having high surface tension.
In our tea, there's tea oil with lower density (therefore it's always on the top of the brewed liquid) appears as we pour water into it.
The air trapped inside this oil layer creates bubbles.

The amount of this oil (and thus also the bubbles to appear) depends on the geographic condition, soil and fertilizing technique employed to raise the tea plant. Moreover theoretically some post-harvesting technique might concentrate this oil content in the tea. At higher brewing temperature (100°C for black tea), the amount of bubbles should decrease along with surface tension decrease.

[orguz]

I was once told that the moon was green cheese, rabbits only ran uphill, and onions were skunk eggs.

This is startling news indeed!

As for bubbles, I have never really noticed any!

You see beecrofter at least Sal has no bubbles in his tea I'm not a chinese tea basher for I gulp it daily, hate to think the radio host is correct.

The case could be true though, perhaps a sign of excessive pesticide use?

[Sydney]

I've never scraped off the bubbles, and there's noting wrong with me!

[Chip]

I've never scraped off the bubbles, and there's noting wrong with me!

Could be a good poll!

Now I feel compelled to taste the bubbles.

[betta]

The case could be true though, perhaps a sign of excessive pesticide use?

Yes if the pesticide is organic substance that doesn't convert to other substance in a plant.
Then this would be the case of DDT. However most of the state of the art pesticides decompose in the plant or upon long contact time with air.
I wouldn't suggest that bubbles are sign of excessive pesticide usage. Some of the organic oolong plants are raised without pesticide (concubine and oriental beauty) but still exhibit many bubbles upon brewing.
I found the older the tea tree, the more the oil. This is true in my puerh case and many puerh lovers here can observe it better.

[orguz]

Some of the organic oolong plants are raised without pesticide (concubine and oriental beauty) but still exhibit many bubbles upon brewing.

This is a good point you make, since this tea needs to be P free!

[wyardley]

Michael @ Tea Gallery has a different take on these two different perspectives. He thinks that someone who says those bubbles are tea oils might have asked someone (a vendor or teacher) about it in the middle of brewing. His contention is that the bubbles that are present in later brews (after the first or second) are, in fact tea oils, while the earlier bubbles are as described.

So according to him, the early ones should be skimmed, but not the later ones.