Shelf life of vacuum-sealed oolong

Owes its flavors to oxidation levels between green & black tea.


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Jul 2nd, '11, 23:19
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Re: Shelf life of vacuum-sealed oolong

by debunix » Jul 2nd, '11, 23:19

Whatsina... wrote:i was also unaware that reroasting a green gaoshan was a useful technique. home roasting sounds like a fun adventure regardless of the outcome.

here's hoping the end result is delicious. good luck and let us know what you do and how it goes!
I took a package of Taiwanese Tie Guan Yin that was not so great to begin with, and had been forgotten in the back of the cabinet. It was not bad, but had definitely lost whatever edge it had. I put it in a flattish bowl in a small convection oven set to 275 degrees, and roasted for a total of just over 20 minutes. During a good part of that time the oven was still heating up, but by the end of it the leaves were turning brown, and their temperature was above 200 degrees per the infrared thermometer (forgot to note the exact temp).

The first infusion is not as fine as the unknown Dong Ding I enjoyed last week, but still, quite tasty, and an improvement over the undistinguished prior incarnation.

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Re: Shelf life of vacuum-sealed oolong

by fire_snake » Aug 13th, '11, 19:46

debunix wrote:
Whatsina... wrote:i was also unaware that reroasting a green gaoshan was a useful technique. home roasting sounds like a fun adventure regardless of the outcome.

here's hoping the end result is delicious. good luck and let us know what you do and how it goes!
I took a package of Taiwanese Tie Guan Yin that was not so great to begin with, and had been forgotten in the back of the cabinet. It was not bad, but had definitely lost whatever edge it had. I put it in a flattish bowl in a small convection oven set to 275 degrees, and roasted for a total of just over 20 minutes. During a good part of that time the oven was still heating up, but by the end of it the leaves were turning brown, and their temperature was above 200 degrees per the infrared thermometer (forgot to note the exact temp).

The first infusion is not as fine as the unknown Dong Ding I enjoyed last week, but still, quite tasty, and an improvement over the undistinguished prior incarnation.
Is this how one would normally roast tea at home? I really must try this. Seems easy enough, though perhaps somewhat imprecise.

Christian

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Aug 13th, '11, 20:16
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Re: Shelf life of vacuum-sealed oolong

by debunix » Aug 13th, '11, 20:16

I did it this way because I hoped it would be slow enough for me to have more control than if I'd used a wok or other utensil over higher heat. I certainly never saw anyone describe doing it quite this way, but I rarely follow directions precisely in the kitchen.

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Re: Shelf life of vacuum-sealed oolong

by fire_snake » Aug 13th, '11, 22:30

debunix wrote:I did it this way because I hoped it would be slow enough for me to have more control than if I'd used a wok or other utensil over higher heat. I certainly never saw anyone describe doing it quite this way, but I rarely follow directions precisely in the kitchen.
Well I just tried this. :twisted:

I managed to turn a not-so-great Oolong into something quite pleasant. Took the bad edge off, and gave it a nice roasty undertone.

The torpedoes be damned. I might just do this again at some point. Though not to good Oolong. ;)

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Re: Shelf life of vacuum-sealed oolong

by edkrueger » Aug 14th, '11, 00:33

I do really long roasts with a tea roaster on a low setting.

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Re: Shelf life of vacuum-sealed oolong

by djlau » Oct 16th, '11, 05:44

After a few years even a vacuum sealed Oolong will become sour, or stale in flavor. Generally, after 5 years the flavor will reach a low point, but wait until the 10th year and you will start to see the sweetness come back. At 15 - 20+ years, the tea will have a very unique, fruity, sweet flavor. These teas are called old teas, Lao Cha, in Taiwan and the good ones sell for very high prices. To get a quality Lao Cha, you have to start with a quality Oolong.

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Re: Shelf life of vacuum-sealed oolong

by Herb_Master » Oct 16th, '11, 12:46

djlau wrote:After a few years even a vacuum sealed Oolong will become sour, or stale in flavor. Generally, after 5 years the flavor will reach a low point, but wait until the 10th year and you will start to see the sweetness come back. At 15 - 20+ years, the tea will have a very unique, fruity, sweet flavor. These teas are called old teas, Lao Cha, in Taiwan and the good ones sell for very high prices. To get a quality Lao Cha, you have to start with a quality Oolong.
How does this work? I was under the impression that to develop with age, an Oolong (particularly the highly oxidised ones), the tea needed a very minimal amount of oxygen. Thus discussions centred on Yixing Tea Canisters often mention them as being superior to 100% airtight canisters for the purpose of allowing them to breathe (ever so slightly).

I often hear from TeaChatters that they like to open their canisters every few months to let a little oxygen in.

Of course there are 2 aspects to Yan Cha, Oxidisation and Roast. Perhaps the allowance of oxygen is to help the roast subside, not for the tea to age on a route to Lao Cha?

The OP is referring to Vacuum Sealed packets does your theory work with these ?

I mainly encounter these type of packets with lightly oxidised Oolongs from Anxi and Taiwan, do these age differently to Highly Oxidised Yan Cha?

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Re: Shelf life of vacuum-sealed oolong

by edkrueger » Oct 18th, '11, 14:53

I find vacuum sealed stuff changes, but never really goes stale. I opened a 2008 Gaoshan today. It tasted pretty mediocre, but that was probably because my tap water sucked. I might write back later when I get some good water.

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Re: Shelf life of vacuum-sealed oolong

by Tead Off » Oct 19th, '11, 01:01

edkrueger wrote:I find vacuum sealed stuff changes, but never really goes stale. I opened a 2008 Gaoshan today. It tasted pretty mediocre, but that was probably because my tap water sucked. I might write back later when I get some good water.
I have had stale, vacuumed packed, older gaoshans. Friends who bought teas years ago but never opened given to me, the tea freak. It develops a distinctive off taste that I've also had in older, stale, Japanese teas. Hard to describe the taste but not really pleasant.

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Re: Shelf life of vacuum-sealed oolong

by djlau » Oct 27th, '11, 02:46

How does this work? I was under the impression that to develop with age, an Oolong (particularly the highly oxidised ones), the tea needed a very minimal amount of oxygen. Thus discussions centred on Yixing Tea Canisters often mention them as being superior to 100% airtight canisters for the purpose of allowing them to breathe (ever so slightly).

I often hear from TeaChatters that they like to open their canisters every few months to let a little oxygen in.

Of course there are 2 aspects to Yan Cha, Oxidisation and Roast. Perhaps the allowance of oxygen is to help the roast subside, not for the tea to age on a route to Lao Cha?

The OP is referring to Vacuum Sealed packets does your theory work with these ?

I mainly encounter these type of packets with lightly oxidised Oolongs from Anxi and Taiwan, do these age differently to Highly Oxidised Yan Cha?
I've only seen Taiwan light-medium roast / lighter oxidation tea aged in vacuum sealed packs. I've been told that they are too susceptible to oxygen and will go bad otherwise.

That's an interesting point about Yan Cha. One very large Yan Cha distributor tells me he re-roasts his tea every couple of years. Perhaps they are not stored in vacuum sealed bags because it would be too much trouble given that this needs to be done. And Yan Cha is probably less susceptible to oxidative degradation due to higher firing and oxidation.

I'd think that it might be possible to age light roast Taiwan Oolong in a large container. However I don't know if it's possible without having to re-roast, and it seems that this would affect end outcome.

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