Save the Tea: Tea Storage 101

Save the Tea: Tea Storage 101

There are several factors that contribute to a good cup of tea, but
this can be a moot point if you haven't gone to the trouble of storing
your tea properly. Tea is a somewhat delicate product. There are many
varieties that don't age well and a few that do, but any one will
produce a better cup if you keep in mind a few basic rules for
storage.

There are essentially five main environmental factors that can
contribute to the ruin of an improperly stored tea. Among these are
air, light, heat and humidity. Perhaps it's oversimplifying a bit, but
these potential pitfalls can be addressed by storing your tea in a
sealed container in a cool, dark, dry place.

Of course, how you store your own tea at home is irrelevant if the tea
has not been properly stored before you purchase it. While buyers
can't have much insight into storage methods from the time the tea was
harvested, you should be wary of loose leaf tea stored in glass
containers on store shelves, as is sometimes the case.

Odor is another enemy of tea, something to keep in mind if you're
storing tea in proximity to aromatic foods or spices. The type of
container used to store tea may also have a bearing on the matter, as
related in this in-depth article from the Cha Dao blog. Because puerh
tea can be aged for as long as several decades, storage is obviously a
very important factor with this variety. For some pointers on puerh
storage, look here, here, here and here. tins, containers

For more general purpose tips on storing tea, refer to this article.
Tea storage is a topic that comes up from time to time at various
online tea communities, including here, here and here.

The decorative and aesthetic aspects of tea containers are beyond the
scope of this article, but some have actually made it into major
museum collections, as noted here and here. For more on tea caddies,
refer to this history and this Wikipedia entry.

http :// www .twinings.ca/?q=blog

Re: Save the Tea: Tea Storage 101

All you have to do is take a whiff. Dont stick your nose directly
over or into the container. Use your hand in a waving cupping motion
over the open container to move ordor to your nostrils on the side. I
kinda like glass jars. I look for the one that is full. If it is
partially empty shake it and make sure nothing sticks to the glass or
lid. I also like to see the leaf. Light penetration by
incandenscence isnt the same as sunlight.


Jim

Dennis Pang wrote:
...duh...
> While buyers can't have much insight into storage methods from the time the tea was
> harvested, you should be wary of loose leaf tea stored in glass
> containers on store shelves, as is sometimes the case.

Re: Save the Tea: Tea Storage 101

On Jul 3, 2:09 pm, Space Cowboy <netst...@ix,net com,com > wrote:
>  I kinda like glass jars.  I look for the one that is full.  If it is
> partially empty shake it and make sure nothing sticks to the glass or
> lid.  I also like to see the leaf.  Light penetration by
> incandenscence isnt the same as sunlight.

Apart from the aesthetics of glass I question this advice on factual
grounds:

a) When very dry - as it should be - tea can "stick" to glass due to
static charge. This may be confused with tea sticking because it is
very damp.

b) Tea leaf, be it green, black or white, retains residual
chlorophyll. Chlorophyll is a light excited photochemical. Absorbed
light causes flavor changes (particularly metallic taints) in stored
tea mediated through residual chlorophyll and its degradation
products. Chorophyll absorbs light strongly in the Red (650-680 nm)
and Near Infra Red (700-706 nm) wavelengths. Incandescent light is
particularly rich in these Red and NIR wavelengths. Hence
incandescent light is actually worse than sunlight in promoting light
induced quality loss (LIQL).

c) While chlorophyll is the main photochemical in tea, it is not the
only one - and other wavelengths may also contribute to LIQL. The
simple rules for storing tea to retain quality - be you producer,
packer, vendor or consumer are:

- Maintain tea below 5-6% moisture content
- Pack within a barrier material that will not allow ingress of taints
or humidity - or egress of tea aroma
- Seal the pack or container hermetically
- Keep below 50 deg F
- Avoid extreme temperature cycling that can dip Equilibrium Relative
Humidity of air within the pack below its Dewpoint (can cause internal
liquid condensation even at low moisture contents)
- Keep out light

Nigel at Teacraft

Re: Save the Tea: Tea Storage 101

Glass is an insulator for static charge. You might get a charge from
the amount of dust but not the glass. Another purchase 'aesthetic'
worth noting. Clumping is an indicator of high humidity. I meant to
say fluorescence which is why most office plants dont thrive. What is
dangerous to any remaining cell in tea is heat. Glass is not a good
heat insulator. Once again not a problem in most AC retail. I think
the reason glass isnt used more often is fragility and weight. Its a
given you can seal glass just as well as any other container. If I'm
an unscrupulous tea seller I probably dont want you to see what you
are buying. I can throw fresh leaves in on the top of a tin and tell
you to smell the ordor. In Chinatown tin and glass are used mainly
for storage. I prefer glass for the first impression.
  
Jim

Nigel wrote:
> On Jul 3, 2:09?pm, Space Cowboy <netst...@ix,net com,com > wrote:
> > ?I kinda like glass jars. ?I look for the one that is full. ?If it is
> > partially empty shake it and make sure nothing sticks to the glass or
> > lid. ?I also like to see the leaf. ?Light penetration by
> > incandenscence?isnt the same as sunlight.
>
> Apart from the aesthetics of glass I question this advice on factual
> grounds:
>
> a) When very dry - as it should be - tea can "stick" to glass due to
> static charge. This may be confused with tea sticking because it is
> very damp.
>
> b) Tea leaf, be it green, black or white, retains residual
> chlorophyll. Chlorophyll is a light excited photochemical. Absorbed
> light causes flavor changes (particularly metallic taints) in stored
> tea mediated through residual chlorophyll and its degradation
> products. Chorophyll absorbs light strongly in the Red (650-680 nm)
> and Near Infra Red (700-706 nm) wavelengths. Incandescent light is
> particularly rich in these Red and NIR wavelengths. Hence
> incandescent light is actually worse than sunlight in promoting light
> induced quality loss (LIQL).
>
> c) While chlorophyll is the main photochemical in tea, it is not the
> only one - and other wavelengths may also contribute to LIQL. The
> simple rules for storing tea to retain quality - be you producer,
> packer, vendor or consumer are:
>
> - Maintain tea below 5-6% moisture content
> - Pack within a barrier material that will not allow ingress of taints
> or humidity - or egress of tea aroma
> - Seal the pack or container hermetically
> - Keep below 50 deg F
> - Avoid extreme temperature cycling that can dip Equilibrium Relative
> Humidity of air within the pack below its Dewpoint (can cause internal
> liquid condensation even at low moisture contents)
> - Keep out light
>
> Nigel at Teacraft

Re: Save the Tea: Tea Storage 101

On Jul 4, 9:46 pm, Space Cowboy <netst...@ix,net com,com > wrote:
> Glass is an insulator for static charge.  You might get a charge from
> the amount of dust but not the glass.  Another purchase 'aesthetic'
> worth noting.  Clumping is an indicator of high humidity.  I meant to
> say fluorescence which is why most office plants dont thrive.  What is
> dangerous to any remaining cell in tea is heat.  Glass is not a good
> heat insulator.  Once again not a problem in most AC retail.  I think
> the reason glass isnt used more often is fragility and weight.  Its a
> given you can seal glass just as well as any other container.  If I'm
> an unscrupulous tea seller I probably dont want you to see what you
> are buying.  I can throw fresh leaves in on the top of a tin and tell
> you to smell the ordor.  In Chinatown tin and glass are used mainly
> for storage.  I prefer glass for the first impression.
>     
> Jim
>
>
>
> Nigel wrote:
> > On Jul 3, 2:09?pm, Space Cowboy <netst...@ix,net com,com > wrote:
> > > ?I  kinda like glass jars. ?I look for the one that is full. ?If it is
> > > partially empty shake it and make sure nothing sticks to the glass or
> > > lid. ?I also like to see the leaf. ?Light penetration by
> > > incandenscence?isnt the same as sunlight.
>
> > Apart from the aesthetics of glass I question this advice on factual
> > grounds:
>
> > a) When very dry - as it should be - tea can "stick" to glass due to
> > static charge.  This may be confused with tea sticking because it is
> > very damp.
>
> > b) Tea leaf, be it green, black or white, retains residual
> > chlorophyll.  Chlorophyll is a light excited photochemical.  Absorbed
> > light causes flavor changes (particularly metallic taints) in stored
> > tea mediated through residual chlorophyll and its degradation
> > products.  Chorophyll absorbs light strongly in the Red (650-680 nm)
> > and Near Infra Red (700-706 nm) wavelengths.  Incandescent light is
> > particularly rich in these Red and NIR wavelengths.  Hence
> > incandescent light is actually worse than sunlight in promoting light
> > induced quality loss (LIQL).
>
> > c) While chlorophyll is the main photochemical in tea, it is not the
> > only one - and other wavelengths may also contribute to LIQL.  The
> > simple rules for storing tea to retain quality - be you producer,
> > packer, vendor or consumer are:
>
> > - Maintain tea below 5-6% moisture content
> > - Pack within a barrier material that will not allow ingress of taints
> > or humidity - or egress of tea aroma
> > - Seal the pack or container hermetically
> > - Keep below 50 deg F
> > - Avoid extreme temperature cycling that can dip Equilibrium Relative
> > Humidity of air within the pack below its Dewpoint (can cause internal
> > liquid condensation even at low moisture contents)
> > - Keep out light
>
> > Nigel at Teacraft- Hide quoted text -
>
> - Show quoted text -

I love drinking it but I have avoided talking about the tea called
Puer Tea, there is so much mystery/secrecy/misinformation/…There is so
much confusion about defining puerh teas, and I am talking about in
Asia. I plan to write a paper on puerh(puer) teas one day. But let me
share with you what I feel as of today on the topic. I talked to some
guys that have a puer-warehouse slightly heated with open water
containers and closed environment, in upstate New York and they were
saying that they were not noticing any aging effects on their green
puers, chemistry-wise; it is too cold most of the time therefore
slowing or halting any (oxidation and fermentation). Also I have heard
from most collectors, fresh fresh air, what this means is there has to
be a reasonable amount of gas exchange from the aging puers. But
remember if you are aging "non-puers", oolongs for example, you don’t
want or need gas exchange because there is enough oxygen in the sealed
container. Because you only want oxidation not fermentation. If you do
air out you aging oolongs you need to heat them again to make sure the
moisture level around 3%, puers are 10% . My puers stay wrapped in
calligraphy cotton paper and never mix greens with blacks, I live in a
humid hot environment which they love and I don’t, but they outnumber
me, heheheh…. Also you can’t make gold out of lead, so if your green
puer is young and of bad quality (weak and without potential), don’t
expect miracles. I usually can drink mine as an aged green puer in
about three to four years and it’s nice, not great but I am happy.
When you buy a new green puer, you need too try it, it should have
what I call an ornery taste or spicy-bitter taste. And black puers
usually don’t age well. But the green-meanies do!!!! ----
icetea -
http :// teaarts.blogspot,com /

Re: Save the Tea: Tea Storage 101

icetea <icetea8@gmail,com > writes:

> [...]
> I love drinking it but I have avoided talking about the tea called
> Puer Tea, there is so much mystery/secrecy/misinformation/…There is so
> much confusion about defining puerh teas, and I am talking about in
> Asia. I plan to write a paper on puerh(puer) teas one day. But let me
> share with you what I feel as of today on the topic. I talked to some
> guys that have a puer-warehouse slightly heated with open water
> containers and closed environment, in upstate New York

Can you say anything more about this place, or are you sworn to secrecy?

> and they were saying that they were not noticing any aging effects
> on their green puers, chemistry-wise; it is too cold most of the
> time therefore slowing or halting any (oxidation and
> fermentation).

But upstate NY isn't Antarctica. Surely it's warm enough for a good
part of the year?

/Lew
---
Lew Perin / perin@acm.org
http :// www .panix,com /~perin/babelcarp.html
recent addition: Mengban

Re: Save the Tea: Tea Storage 101

On Jul 4, 11:20 pm, Lewis Perin <pe...@panix,com > wrote:
> icetea <icet...@gmail,com > writes:
> > [...]
> > I love drinking it but I have avoided talking about the tea called
> > Puer Tea, there is so much mystery/secrecy/misinformation/…There is so
> > much confusion about defining puerh teas, and I am talking about in
> > Asia. I plan to write a paper on puerh(puer) teas one day. But let me
> > share with you what I feel as of today on the topic. I talked to some
> > guys that have a puer-warehouse slightly heated with open water
> > containers and closed environment, in upstate New York
>
> Can you say anything more about this place, or are you sworn to secrecy?
>
> > and they were saying that they were not noticing any aging effects
> > on their green puers, chemistry-wise; it is too cold most of the
> > time therefore slowing or halting any (oxidation and
> > fermentation).
>
> But upstate NY isn't Antarctica.  Surely it's warm enough for a good
> part of the year?
>
> /Lew
> ---
> Lew Perin / pe...@acm.org http :// www .panix,com /~perin/babelcarp.html
> recent addition: Mengban

==> Can you say anything more about this place, or are you sworn to
secrecy?
just think where your good puerhs are coming from, grown in china/
yunnan but stored in hong kong and taiwan, the weather bewteen there
and upstate NY is a world apart. if you have any ideas lets here
them.
[[
as time goes by and more westerners collect green puerhs it will be
interestiing what kind of results they will get i would assume down
south(USA) would do good....
myself i keep my green puerhs open but wrapped in cotton paper and in
a circulated room and it is in taiwan humid and hot, i get results
starting in 3years of aging a new green puerh. it should be noted that
you cant get good tea from bad tea it has to be of good quality large
leaf not overly compressed and it should not feel like it is coated
with plastic which i have seen some times when making green or black
puerh cakes they imprint chinese characters or other images they use
some kind of vegetable coating and the cake cant breath,,,,,,,bad bad

==> But upstate NY isn't Antarctica. Surely it's warm enough for a
good
> part of the year?
yes warm but not hot and to short of a time anyway ,,,they only have a
couple months in the 80's'F

--icetea

Re: Save the Tea: Tea Storage 101

> On Jul 3, 2:09 pm, Space Cowboy <netst...@ix,net com,com > wrote:
>> Light penetration by incandenscence isnt the same as sunlight.

Nigel wrote:
> c) While chlorophyll is the main photochemical in tea, it is not the
> only one - and other wavelengths may also contribute to LIQL.

Just want to support Nigel's point with insight from another field where
I've had some experience: document conservation, including prints and
photographs. The spectral tail of ordinary yellowish incandescent bulbs
still contains a bit of UV radiation; halogen bulbs much more so.
Fluorescent bulbs generate very nearly 100% UV light inside the
envelope; this is down-converted by phosphors to the visible range.
Since the phosphors are efficient UV absorbers, fluorescent bulbs can
emit less UV light than incandescents, even though they are much richer
in the blue. (In fact, it's the departure from the "black body" spectrum
that makes fluorescent lamps so efficient.) So conservators may use UV
screens on both types of lamp.

However, as Nigel points out, there's plenty of regrettable
photochemistry that can be induced by visible light, even in the
lowest-energy deep red. It's a simple question of photon quantum energy
vs. activation threshold for pernicious chemical reactions, some of
which (like singlet oxygen production) happen even with IR light.

The "zeroth law of photochemistry" says that only absorbed light can
have an effect. the reverse isn't strictly true; most absorbed visible
light will be dumped as heat. But large biomolecules tend to be
vulnerable to photochemistry under quite mild conditions. And as has
been mentioned elsewhere, the results of this kind of reaction tend to
include not just the incremental loss of desirable flavor elements, but
also the creation of new ones that can be offensive even in minute amounts.

-DM

Re: Save the Tea: Tea Storage 101

A scientific tall tale. No more than heat perse, humidity perse,
ordor perse. In fact anyone of these is worse than light perse IMHO.
Both of you are arguing what is known to happen on the bush ie
photochemistry. It doesnt continue after the leaf is kill-green by
whatever treatment. The reason we know that is because tea doesnt
decay because of any active leftover membrane organics. When the leaf
falls off the tree it stops turning carbon dioxide into oxygen.
Spores,yeast,germs in the compost turns oxygen into carbon dioxide.
Your double slit infintestimal taste differences could as well be a
positive when the wave becomes a photon. Tea vendors are jumping on
the tea in glass bandwagon for product presentation. Assuming pyrex
doesnt filter your nasty wavelengths you can see if BLC is the shell
or trail style, TGY is light or heavy roast, Dong Ding from China
looks like Dong Ding from Taiwan, any dust how in the Sencha, Da Hong
Pao looks like your worst tea nightmare. I wished I could see every
tea I was buying off the shelf. If any tea could use some additional
photochemistry in a tanning salon it would be some white tea I drink
which has hardly seen the light of day. Storing tea in a glass doesnt
make it a terrarium.

Jim

PS Presented in the modern debate style where the affirmative shear
number of cacauphonous arguments win.

...clap on clap off...
DogMa wrote:
> > On Jul 3, 2:09 pm, Space Cowboy <netst...@ix,net com,com > wrote:
> >> Light penetration by incandenscence isnt the same as sunlight.
>
> Nigel wrote:
> > c) While chlorophyll is the main photochemical in tea, it is not the
> > only one - and other wavelengths may also contribute to LIQL.
>
> Just want to support Nigel's point with insight from another field where
> I've had some experience: document conservation, including prints and
> photographs. The spectral tail of ordinary yellowish incandescent bulbs
> still contains a bit of UV radiation; halogen bulbs much more so.
> Fluorescent bulbs generate very nearly 100% UV light inside the
> envelope; this is down-converted by phosphors to the visible range.
> Since the phosphors are efficient UV absorbers, fluorescent bulbs can
> emit less UV light than incandescents, even though they are much richer
> in the blue. (In fact, it's the departure from the "black body" spectrum
> that makes fluorescent lamps so efficient.) So conservators may use UV
> screens on both types of lamp.
>
> However, as Nigel points out, there's plenty of regrettable
> photochemistry that can be induced by visible light, even in the
> lowest-energy deep red. It's a simple question of photon quantum energy
> vs. activation threshold for pernicious chemical reactions, some of
> which (like singlet oxygen production) happen even with IR light.
>
> The "zeroth law of photochemistry" says that only absorbed light can
> have an effect. the reverse isn't strictly true; most absorbed visible
> light will be dumped as heat. But large biomolecules tend to be
> vulnerable to photochemistry under quite mild conditions. And as has
> been mentioned elsewhere, the results of this kind of reaction tend to
> include not just the incremental loss of desirable flavor elements, but
> also the creation of new ones that can be offensive even in minute amounts.
>
> -DM
...the clapper...

Re: Save the Tea: Tea Storage 101

On Jul 7, 2:40 pm, Space Cowboy <netst...@ix,net com,com > wrote:
 >Tea vendors are jumping on
> the tea in glass bandwagon for product presentation.
> I wished I could see every tea I was buying off the shelf.
>

That my be so but I would tend to avoid tea vendors who put "product
presentation" above maintaining quality.
Keeping tea in a light impervious container does not preclude your
opening it to evaluate the contents before buying.

Nigel at Teacraft

Re: Save the Tea: Tea Storage 101

On Jul 7, 2:40 pm, Space Cowboy <netst...@ix,net com,com > wrote:
> A scientific tall tale.  No more than heat perse, humidity perse,
> ordor perse.  In fact anyone of these is worse than light perse IMHO.

If only biological systems were so simple! No one of these is worse
than the other - each can be worse at some part of its ambient range,
particularly when synergizing with another. Cold does not protect if
moisture is present. Heat offers no quality problem in the absence of
moisture but is a killer when moisture is high (plus all the shades of
difference between the LO and HI ranges of each parameter). Light
damage I suspect becomes worse in the presence of oxygen, less so in a
vacuum. Light damage is also accelerated at higher tea moistures.

Nigel at Teacraft

Re: Save the Tea: Tea Storage 101

On Jul 7, 2:40 pm, Space Cowboy <netst...@ix,net com,com > wrote:
> Both of you are arguing what is known to happen on the bush ie
> photochemistry.  It doesnt continue after the leaf is kill-green by
> whatever treatment.  The reason we know that is because tea doesnt
> decay because of any active leftover membrane organics.  When the leaf
> falls off the tree it stops turning carbon dioxide into oxygen.

Photochemistry is not just a biological process and indeed can proceed
long after the tea is "dead". In my tea R&D days I ran artificial
light storage tests with leaf teas and got metallic tastes - these
were not "double slit infintestimal taste differences" - these were
ugh! nasty tastes. I was also working with a tea product that was
pulled from the market due to light induced photochemistry. Lipton
Ice Tea was launched in France in the 70s in glass bottles and after a
few weeks consumer reports flooded in concerning off flavor. This was
eventually traced to presence of minute amounts of cholorophyll from
the tea extract retaining some photochemical activity which when the
bottles were displayed in light induced some unwanted flavors .
Bottle with tea = problem. Bottle without tea = no problem. Bottle
with tea in dark = no problem. The answer was to use aluminum cans.
Traditionally brewers had always used dark brown bottles, and vintners
dark green bottles, to exclude light and retain quality. Yes, I know
that white wines are presented in clear bottles - but these are made
with the grape skins (that are rich in photochemicals) removed.
Present day RTD tea drinks use a variety of proprietary tricks to
prevent off flavors.

Nigel at Teacraft

Re: Save the Tea: Tea Storage 101

Diluted tea in solution is a different problem than dry tea in a jar.
Your off taste probably included other factors besides photochemistry
like bacteria eating sugar reacting with light. It is common in
science to isolate a problem, find a fix which solved another unknown
related problem.
Jim


Nigel wrote:
> On Jul 7, 2:40?pm, Space Cowboy <netst...@ix,net com,com > wrote:
> > Both of you are arguing what is known to happen on the bush ie
> > photochemistry.
...
> Photochemistry is not just a biological process and indeed can proceed
> long after the tea is "dead".
...
> Nigel at Teacraft