Ten Ren Lung Ching "Oil Slick"?!

As a chemist, I've seen this phenomenon many times when a small amount of an oily phase separates from an aqueous liquid. The oily phase is usually near its freezing point, contains dissolved material near saturation, or is otherwise nearly solid.

You mention that it's an LJ. I believe that these are always wok-fried to get that unusual leaf form. Sohe slick is probably lard, though perhaps just peanut oil, with tea chemicals dissolved in it.

-DM

Dom> OK, now this is strange, I bought some 2006 Spring picked Lung Ching

Thanks, I never thought of that. Like I said I had noticed a tiny bit of oil/sludge before on really freshly manufactured greens of different types but it was never terribly bad and I always attributed it to the freshness of the tea and the natural oils coming out, never due to the actual process. I'll try to take a photo of what it looks like tomorrow just for everyone to see because in over 8 years this is a first for me.

thanks again,

- Dominic

Sounds to me like you possibly bought some 2005 re-fired, oiled tea. TianFu (ten ren) here is notorious for marketing old tea and claiming it's new. They usually put oil on the leaves to preserve the tea so it can be sold for a longer period of time. Spring LJ becomes stale quickly, even if it's put in air tight bags.

It is a fairly real possibility I guess. I mainly drink greens, and once a year (normally a bit earlier in the year than now though) I will buy a fresh LJ. I will be highly disappointed if indeed that is the case, as my opinion of Ten Ren was mighty low to begin with... it's hard to imagine it being lower. @$120/lb. it is disgraceful. The thing about it was that when I checked it out, it appeared to be about right by my senses... however now after closer inspection it does seem a bit of a almost unnoticeable "coating" on the leaves. The flavor is actually pretty good though, nothing off-putting there, I'm going to do a quick rinse of some leaves and brew another cup to see what happens.

- Dominic

It is a fairly real possibility I guess. I mainly drink greens, and

Ya, me and Tianfu have beef. Good pal of mine bought what would be a sample size of some GaoShan tea from there and got ripped off by about

I wouldn't spend more than a few bucks at Tianfu (ten ren), if that.

I can only agree, I see it mostly on black teas, it is probably a sediment from tap water, once you purify it with water filter like Brita, the oily sediment disappear.

Eureka! I have found the culprit to be the new bottled spring water I purchased. I promptly threw away the rest of the water, it was the first time I bought the Wal-Mart Spring Water in a 1-gallon jug (I normally use a different brand spring water) and the last time. I barely shop at Wal-Mart as it is and now I see why. I'm not sure what the hell is in this "spring water" but it is not good. I brewed a cup of the same lung ching at home with plain tap water and it was fine, I then tried a few different teas with the Wal-Mart water and to varying degrees I got an oil slick... but none as pronounced as the Lung Ching. It must be reacting with something. Either way, that water is not pure because no other water has this effect. At least I solved the mystery.

- Dominic

This "spring water" is probably very mineralized and the oily slick consist of minerals and calcium from that water...

another mystery solved :-)