White Tea Expiration?

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T.T.
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Mon Jan 25, 2021 9:20 am

Hello,

I am looking to buy some quality white tea. When I look at Jing Tea Shop’s white teas, they seem to be a few years old? Their Bai Mu Dan was harvested in the spring of 2019 and their Bai Hao Yin Zhen was harvested in the spring 2018.

I have read that white tea can be aged. So I am confused. Does white tea expire if it can be aged? Is Jing Tea Shop a good shop to buy white tea?

Background: I am a newbie to loose leaf green and white tea. I have been drinking tea bags for several years. I am afraid if I buy low quality white tea that I won’t know if it is any good or not as I am new to loose leaf.

Tamara
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chadao
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Mon Jan 25, 2021 10:46 pm

Welcome to the world of looseleaf tea!

White tea can indeed be aged, and in fact, higher quality white tea can absolutely be aged for a number of years. The character of the tea changes over time, and some people will say it becomes more complex as it goes. White tea can lose its character and taste if it's aged in an open bag or something similar, with too much air flow.

White tea comes in different grades and qualities, with differing harvest times and types of leaves harvested to make the tea. I'm not sure the store you're referencing, but if you can find a good Fujian white tea, it can really impress you.

What interests you in white tea?
Ethan Kurland
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Mon Jan 25, 2021 11:09 pm

I am replying because you posted in the morning & no one else replied all day. I believe others here know a lot more about white tea than I do. If I am wrong, I trust they will correct me.

1. Tea waiting to be purchased does not = the aging of tea. Aging tea usually involves conditions aiming to give leaves some character that is less likely to happen just be stored in common ways.

2. White tea is often delicate in body & delicate in flavor. Being a bit stale could be tougher on delicate teas than on others. (I used to drink white teas from Nepal. A couple of them did not diminish significantly after I had had them for a few months. Most already started to fade after 3 months.

I wonder why you seem to be focusing on white tea now. Good white tea is more difficult to obtain than most other teas. Aged white tea is disappointing more often than it is satisfying though it almost always cost a lot.

If you are right at the beginning of drinking loose tea, I suggest telling us what kind of tea you drank in teabags & what more you would like to enjoy that that tea did not provide you. Then you could be advised easily. Cheers
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Bok
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Mon Jan 25, 2021 11:29 pm

Correct me if I am wrong. But tea itself will not expire. It might get to a stage where it is devoid of any flavours, but some can recover after a long storage. How long is long? Well as long as you are willing to wait. 10-20-50+ years. Unless it gets wet, it won't go off.

Other than that, what Ethan said.
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mbanu
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Tue Jan 26, 2021 5:19 am

In the production process of white tea, an important step is missing, and this changes how white tea acts.

White tea is not fired at a high temperature (sometimes this is called a kill-green). This is a step that deactivates many enzymes that are responsible for tea oxidation. Some folks believe that skipping this step actually improves the flavor of the fresh tea, at the cost of shelf life. That is why traditionally white tea was considered delicate, and needed to be drunk very fresh.

With a tea that has gone through a kill-green, the initial quality is slightly decreased, but then it is maintained at that quality for many months, before heat-resistant enzymes cause the tea quality to decline.

With tea that has not gone through a kill-green, the quality sharply drops off after the tea is made, as once it absorbs moisture from the air, the oxidation process starts back up again at random.

However, it was discovered that this process can actually have a preservative effect on the shelf life of old white teas in less dry places, as the tea slowly progresses from white tea to black tea before going stale. This randomized black tea is not normally as good as freshly-made black tea, but allows a tea to be pleasant to drink long after it normally would have gone stale.

There are a lot of storage condition issues with white tea, however. Just like other teas it can absorb aromas easily. Because it is not rolled, it is easily crushed. Because it is happening at random, the results are not consistent (some of the worst teas I can ever remember having were old white teas). You also start to get pu'er type problems with authenticity when you need to keep track of where the tea has been for however many years.

It is a useful tea if you live somewhere where made teas quickly spoil but where tea-bushes can't be grown, and the traditional fresh white tea has special charms that are easier to appreciate as shipping speeds increase.

Some vendors take advantage of this confusion to try to sell last season's fresh white tea as this season's aged white tea. For fresh white tea the best thing would be to wait for the spring harvest.
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aet
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Tue Jan 26, 2021 7:12 am

different environment requires different conditions for storage in order to preserve tea leaf either dry out or get moldy ( or very wet taste ) . In any case , the enzyme activity is still on , even if environment is not hot or humid like in Fujian ( unless you put it in freezer or something )
In fact, Fujian concept of processing is bit different from Yunnan one ( longer withering time and higher drying temperatures ..all that reduces the enzyme activity ), yet it ages faster ...but there.... or in other hot & humid places..
Also thanks to the environment and "smart" processing , quite a lot of fake old white tea can be found there on market. ..different capture.

Yunnan for change , does "ti xiang" on some white, to elevate aroma and sweetness like you may be familiar with some black oolongs. I think the Fujian producers in Simao started with this.
The effect, or should I say - the defect is the same as with new concept of puerh tea " gao wen sha qing " - high temp. kill green. The tea is super nice, aromatic, sweet as candy but has it's life time , which of course might be extended in some hot and humid entertainment where "everything" is ageing no matter the processing ;-) ...it's just not the proper ageing but just changing taste by absorbing humidity and transforming the taste on fungal level , which can be reflected in taste .
If white tea pressed , it already has gone trough the steaming ( hot & humid ) so there is some quick and "short time ageing" introduced to leaf , that's why one has to know which loose leaf to use for pressing.....not the new concept made one with "ti xiang"
If loose leaf well stored in sealed pouch ( preferably some bigger bag with some extra space inside ) it ages in its "own" environment. In open , there is a risk of excessive oxidation or even drying out, therefore loosing taste.

The 2 years of storage does make difference in taste and costs for storage are understandable ( especially if loose leaf ) . Should you like new or aged , it is up to you to try first. Choose from 1 vendor new and their storage aged . Try Yunnan and Fujian also ( both -new and aged ) , then will get a better picture.

In my experience , slower ageing ( in relatively dry environment ) preservers original flowery notes and the fruity ones come around in gentle background. In humid & hot environment , the flower notes are quite gone but exchanged for honey sweet ones with much intensive fruity body in taste.

When compare those teas, use same technique (water ratio, steeping times ..etc. ) to get the clear idea about how taste is adjusted with processing and ageing.

At most importantly, have fun !
m2193
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Sat Mar 13, 2021 5:32 pm

To hop on to this post, does anyone have any good paper recommendations on the enzymatic activity associated with white tea aging? I read somewhere today that latent enzymatic activity in white tea is similarly prevalent to that of sheng pu'er, which I found interesting. Definitely not something I've thought about, but a concept I find interesting since I've worked with some enzymes before and due to the way we process/culture them are not super stable under what would be normal tea storage conditions (of course, lab work =/= reality). I did goof around with a green tea and white tea sample to test antioxidant level in a FRAP assay, but don't think the anyone here will let me mess with the mass spec for now :lol:
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mbanu
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Sun Mar 14, 2021 9:52 am

m2193 wrote:
Sat Mar 13, 2021 5:32 pm
To hop on to this post, does anyone have any good paper recommendations on the enzymatic activity associated with white tea aging? I read somewhere today that latent enzymatic activity in white tea is similarly prevalent to that of sheng pu'er, which I found interesting. Definitely not something I've thought about, but a concept I find interesting since I've worked with some enzymes before and due to the way we process/culture them are not super stable under what would be normal tea storage conditions (of course, lab work =/= reality). I did goof around with a green tea and white tea sample to test antioxidant level in a FRAP assay, but don't think the anyone here will let me mess with the mass spec for now :lol:
This is the same enzymatic activity associated with black tea oxidation, so any papers that focus on the oxidative process in black tea will also be helpful for white tea. White tea and black tea start and end identically, with withering and drying, but because there is no rolling in white tea, no controlled oxidation, and no firing, these steps are left to chance after the fact, a bit like making wort for beer and then leaving it outside to finish up. :) However, sometimes there are certain perks of doing it this way, which is why it found a niche in some regions.
m2193
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Sun Mar 14, 2021 11:47 am

@mbanu

Thanks for the info! I'll go look at it more when I'm free.
m2193
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Mon May 03, 2021 7:20 pm

m2193 wrote:
Sat Mar 13, 2021 5:32 pm
To hop on to this post, does anyone have any good paper recommendations on the enzymatic activity associated with white tea aging? I read somewhere today that latent enzymatic activity in white tea is similarly prevalent to that of sheng pu'er, which I found interesting. Definitely not something I've thought about, but a concept I find interesting since I've worked with some enzymes before and due to the way we process/culture them are not super stable under what would be normal tea storage conditions (of course, lab work =/= reality). I did goof around with a green tea and white tea sample to test antioxidant level in a FRAP assay, but don't think the anyone here will let me mess with the mass spec for now :lol:
Well as an update, I ended up with 3 samples ran through the LC/MS. The problem is that I ended up with 1593 features in the chart for a (a generic Chinese 红茶, or what us Westerners would call black tea) vs. b (a Mi Xiang black tea from Tealife HK), and 1840 in the chart for the a vs. c (a generic Chinese supermarket jasmine oil scented green tea) samples, so not at all practical for general analysis. If anyone is curious to see the data (just a bunch of m/z vs. retention times), I can share the charts, but I don't foresee them being very useful to anyone.
Last edited by m2193 on Mon May 03, 2021 7:31 pm, edited 1 time in total.
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LeoFox
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Mon May 03, 2021 7:26 pm

Can you show the chromatograms aligned top down at same scale?
m2193
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Mon May 03, 2021 7:32 pm

LeoFox wrote:
Mon May 03, 2021 7:26 pm
Can you show the chromatograms aligned top down at same scale?
I've attached the charts below. I've never had to use LC/MS or work with data from it for anything I've done in the lab so I'm at a loss. I think(?) I've been able to identify some flavonoids, but that's about it.
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LeoFox
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Mon May 03, 2021 8:10 pm

Which one is which?
m2193
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Mon May 03, 2021 8:15 pm

1840 is the chart for the a vs. c (a generic Chinese supermarket jasmine oil scented green tea) and the one with 1593 features in the chart is for a (a generic Chinese 红茶, or what us Westerners would call black tea) vs. b (a Mi Xiang black tea from Tealife HK)
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LeoFox
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Mon May 03, 2021 8:34 pm

That's quite interesting! Dont stop running different teas! I think your work deserves its own thread in research for sure
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