Hi,

Another question here about oolong teas that I'm hoping someone can answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston

"winston" ha scritto nel messaggio
...
Hi,

Another question here about oolong teas that I'm hoping someone can
answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more
oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston


Oxidation and roasting are two complitely separate phases of oolong tea
processing. After picking and withering, tea leaves are left to oxidize to
the wanted degree of oxidation and then fixated by a first firing. The
indication on roasting you found are related to the final process which is
done in the rifining of oolong teas in order to add a "roasty" taste and in
some case also to decrease astringency. So oxidation and roasting are
unrelated and you can find teas with combination of different degrees of
these two precesses.
L

I would like to add only a few remarks on roasting.

I personally do not know which can be considered the differences between
traditional and ancient oolong production methods. What I will try to
describe are the main phases of the process used for yan tea, TGY and
phoenix mountain dancong teas, which I could see in China. The biggest
difference is in the rolling process, but other phases are basically the
same and differ only in their degree and in the way they are performed.

Since my English is terrible and I do not make a consistent use of terms, I
want first to fix some concepts on these processes.

I will refer to "pan-roasting" (I used the term "pan-firing") in order to
translate the Chinese term "chao". I do not like too much the term "frying"
since there is no oil used in this process.

With the English term "baking" I will translate the Chinese word "bei" (In
my previous message I used the term "roasting").

Pan-roasting is a process common to all green and oolong teas. It is so
called since it was performed in an pan. Many green teas are still roasted
in wok-like pans today, but most of oolongs are "pan-roasted" in a rotating
heated iron barrel.

Pan-roasting process has these main purposes.
1) Fixation ("Shaqing", killing the green): stop all enzymatic oxidation
activities in the tea leaves at the wanted degree (nominally 0% for greens,
or 20-60 for oolongs).
2) Cook the leaves in order to decrease water content and make them soft and
suitable for the subseguent "rolling process".
After pan-roasting, tea leaves must not be dry, but soft and pliable and the
more or less time you roast is adjusted in order to abtain this result.
Being still rich in water content, in this phase tea leaves change and
improve their taste and fragrance but get little "roasty" taste.

After rolling (that in the case of TGY can be quite complicate), rolled (and
so shaped) tea leaves undergo a first "baking" which has only the purpose of
drying complitely them. This process might be performed using some special
"baking baskets" (beilong) made with a frame of bamboo with a metal net in
the middle and posed on hot charcoal, or, in a more modern fashoned way,
with a multi-layers hot air dryer.

All the phases above are usually performed directly by the producers
(farmer) in they own, or collective, premises. The result (fermented, rolled
and dryed leaves) is called "mao cha", semi-processed tea. Tasting this tea
you can apreciate very well the quality of the plants and the way all the
above processes have been carried out, but tea leaves have no "baky" or
"roasty" taste.

Mao cha is not intended for direct consumption and needs a finishing
process. This might be performed by the producer (in the case of middle or
big scale producers) or more often by a whole-sale dealer who collect
mao-cha from many different small producers (a widespread practise in Anxi
area).

Finishng process includes the phases of removal of stems, sieving, final
baking.

Final baking is tipically performed in baking-baskets. It is a very delicate
and important phase, the one that brings tea leaves to the wanted final
"roast degree". As Ripon has already explained, this degree which might vary
a lot, but it is with the final baking that, varying the process timing, an
oolong tea can become a light, medium or heavy roasted one, and not during
the pan-roasting process.

Sorry for being so verbose.
Livio



"Ripon" ha scritto nel messaggio
om...
Livio is very much right about "oxidation and roasting are unrelated".
I will start from this point-

Oxidation process can also make some Oolong more roast and flowery
fragrant. Oolong tea can undergo 20-60% oxidation. When they pan-fry
some oolong teas- timing can vary. That gives Oolong more roast or
more flowery flavor. Some Oolong teas pan-fried longer then others.
When they talk about "medium or dark roast"- they mean the timing of
pan frying. But again oxidation level has an big impact on Oolong
taste. Darjeeling Oolong, Bai Hao and some other Oolong undergo
through less oxidation. Miang Xiang Oolong undergo through higher
oxidation and also pan fried longer time. So the straight answer of
your question is- yes you Ti Guan Yin can be medium and dark roasted.

Ti Guan Yin can be many types. I have tried more then 15 types. If you
try different kinds of TGY, you will see they can be also marked as-
Ti Guan Yin, Monkey picked Ti Guan Yin, TGY 1st grade, TGY K100,
superior, tei baoota, top confou etc. etc. Ti Guan Yin can have
different taste- some has more roast flavor and aroma, some are more
floral, some can be very aromatic or even can be mild aromatic. All
this happened for the processing- Oxidation or roasting timing.

High grade Oolong processing is still considered as one of the Chinese
tea master's secret. Oolong can be processed in two different ways-
one is the traditional method, another is ancient China method. You
can tell this if you carefully take your infused oolong tea leaves
under magnifying glasses(That's another topic).

Their is no straight forward answer about Oolong processing. Hope I
have answered your question, Thanks.

Ripon
Vienna,VA

"Livio Zanini" wrote in message
Another question here about oolong teas that I'm hoping someone can
answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors
note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly
oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more
oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston


Oxidation and roasting are two complitely separate phases of oolong tea
processing. After picking and withering, tea leaves are left to oxidize
to
the wanted degree of oxidation and then fixated by a first firing. The
indication on roasting you found are related to the final process which
is
done in the rifining of oolong teas in order to add a "roasty" taste and
in
some case also to decrease astringency. So oxidation and roasting are
unrelated and you can find teas with combination of different degrees of
these two precesses.
L

Livio Zanini wrote:
I would like to add only a few remarks on roasting.

*snip*

Sorry for being so verbose.
Livio


Not all all, *thank you* for being so verbose.

--
Hennes

Thank you Livio! This really helps me understand why there are so many
tastes for oolong teas. If I understand correctly, then it is possible to
have a light oxidized oolong (i.e 20%) that is a heavy roast?

I am wondering if the oolong processing in Taiwan is similar to China ? In
my experience, the oolongs from Taiwan such as Tung Ting, Bao Zhong, Gao
Shan all have much more flowery notes than some that I've tried from
mainland China. Is this because they are less roasted? I'm making the
assumption (incorrectly perhaps?) that more flowery means less roasting and
vice versa?

Winston

"Livio Zanini" wrote in message
...
I would like to add only a few remarks on roasting.

I personally do not know which can be considered the differences between
traditional and ancient oolong production methods. What I will try to
describe are the main phases of the process used for yan tea, TGY and
phoenix mountain dancong teas, which I could see in China. The biggest
difference is in the rolling process, but other phases are basically the
same and differ only in their degree and in the way they are performed.

Since my English is terrible and I do not make a consistent use of terms,
I
want first to fix some concepts on these processes.

I will refer to "pan-roasting" (I used the term "pan-firing") in order to
translate the Chinese term "chao". I do not like too much the term
"frying"
since there is no oil used in this process.

With the English term "baking" I will translate the Chinese word "bei" (In
my previous message I used the term "roasting").

Pan-roasting is a process common to all green and oolong teas. It is so
called since it was performed in an pan. Many green teas are still roasted
in wok-like pans today, but most of oolongs are "pan-roasted" in a
rotating
heated iron barrel.

Pan-roasting process has these main purposes.
1) Fixation ("Shaqing", killing the green): stop all enzymatic oxidation
activities in the tea leaves at the wanted degree (nominally 0% for
greens,
or 20-60 for oolongs).
2) Cook the leaves in order to decrease water content and make them soft
and
suitable for the subseguent "rolling process".
After pan-roasting, tea leaves must not be dry, but soft and pliable and
the
more or less time you roast is adjusted in order to abtain this result.
Being still rich in water content, in this phase tea leaves change and
improve their taste and fragrance but get little "roasty" taste.

After rolling (that in the case of TGY can be quite complicate), rolled
(and
so shaped) tea leaves undergo a first "baking" which has only the purpose
of
drying complitely them. This process might be performed using some special
"baking baskets" (beilong) made with a frame of bamboo with a metal net in
the middle and posed on hot charcoal, or, in a more modern fashoned way,
with a multi-layers hot air dryer.

All the phases above are usually performed directly by the producers
(farmer) in they own, or collective, premises. The result (fermented,
rolled
and dryed leaves) is called "mao cha", semi-processed tea. Tasting this
tea
you can apreciate very well the quality of the plants and the way all the
above processes have been carried out, but tea leaves have no "baky" or
"roasty" taste.

Mao cha is not intended for direct consumption and needs a finishing
process. This might be performed by the producer (in the case of middle or
big scale producers) or more often by a whole-sale dealer who collect
mao-cha from many different small producers (a widespread practise in Anxi
area).

Finishng process includes the phases of removal of stems, sieving, final
baking.

Final baking is tipically performed in baking-baskets. It is a very
delicate
and important phase, the one that brings tea leaves to the wanted final
"roast degree". As Ripon has already explained, this degree which might
vary
a lot, but it is with the final baking that, varying the process timing,
an
oolong tea can become a light, medium or heavy roasted one, and not during
the pan-roasting process.

Sorry for being so verbose.
Livio


*snip*

Thanks, Ripon. Could you tell us more about the difference between
traditional method and ancient China method? Sounds intriguing. Also, what
are the names of the teas using the ancient China method and are they
available for mere mortals to buy?

Winston
"Ripon" wrote in message
om...
Livio is very much right about "oxidation and roasting are unrelated".
I will start from this point-

Oxidation process can also make some Oolong more roast and flowery
fragrant. Oolong tea can undergo 20-60% oxidation. When they pan-fry
some oolong teas- timing can vary. That gives Oolong more roast or
more flowery flavor. Some Oolong teas pan-fried longer then others.
When they talk about "medium or dark roast"- they mean the timing of
pan frying. But again oxidation level has an big impact on Oolong
taste. Darjeeling Oolong, Bai Hao and some other Oolong undergo
through less oxidation. Miang Xiang Oolong undergo through higher
oxidation and also pan fried longer time. So the straight answer of
your question is- yes you Ti Guan Yin can be medium and dark roasted.

Ti Guan Yin can be many types. I have tried more then 15 types. If you
try different kinds of TGY, you will see they can be also marked as-
Ti Guan Yin, Monkey picked Ti Guan Yin, TGY 1st grade, TGY K100,
superior, tei baoota, top confou etc. etc. Ti Guan Yin can have
different taste- some has more roast flavor and aroma, some are more
floral, some can be very aromatic or even can be mild aromatic. All
this happened for the processing- Oxidation or roasting timing.

High grade Oolong processing is still considered as one of the Chinese
tea master's secret. Oolong can be processed in two different ways-
one is the traditional method, another is ancient China method. You
can tell this if you carefully take your infused oolong tea leaves
under magnifying glasses(That's another topic).

Their is no straight forward answer about Oolong processing. Hope I
have answered your question, Thanks.

Ripon
Vienna,VA

"Livio Zanini" wrote in message
Another question here about oolong teas that I'm hoping someone can
answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors
note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly
oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more
oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston


Oxidation and roasting are two complitely separate phases of oolong tea
processing. After picking and withering, tea leaves are left to oxidize
to
the wanted degree of oxidation and then fixated by a first firing. The
indication on roasting you found are related to the final process which
is
done in the rifining of oolong teas in order to add a "roasty" taste and
in
some case also to decrease astringency. So oxidation and roasting are
unrelated and you can find teas with combination of different degrees of
these two precesses.
L

Hi Michael,

roasting should stop oxidation, and lead to taste differences. *Exactly*
what they are eludes me sometimes. That's why I too need a bit of
clarification.

Me too. I have problems with English.
So far, I thought the term "roast" for tea was reserved to the roasting done
to certain teas (mostly green or oolong) after the whole first process is
done, after they are completely oxided/stopped/dried/fermented. The
operation to stop the oxidation is called anything but roasting (pan-firing,
steaming, heating, cooking....).
My understanding is the packages allude to that second-process roasting.

Not all oolongs are roasted. You can roast your tea yourself at home (it's a
good way to recycle greens that are getting a bit old) to see the effect.

It appears
to me that if a tea is more heavily roasted, but not very highly oxidized,
it will appear quite dark as dry leaf, but become much greener in the
water.

No, in my experience, they appear very dark brown/orange in the water, they
get closer to coffee. In taste too.

About the health point of view. I don't have the reference here, but
roasting tea make it lose some exciting substances like cafeine/theine, so
roasted teas can be better for children or to drink in the evening if you
fear to have problems to sleep. They also have properties for Chinese
medicine, and are given to people that are sick and recovering. But they
lose vitamins or I don't remember what.

Kuri

Kuri and Michael wrote:
Recently I bought a hand held, hemispheric, handled, unglazed ceramic
"roaster" which I use to roast a half ounce of tea at a time by holding
the
roaster over a flame and turning constantly. I've been enjoying this since
there are indeed changes that occur with my additional roast.
Not all oolongs are roasted. You can roast your tea yourself at home
(it's a
good way to recycle greens that are getting a bit old) to see the
effect.
....
About the health point of view. I don't have the reference here, but
roasting tea make it lose some exciting substances like cafeine/theine,
so
roasted teas can be better for children or to drink in the evening if
you
fear to have problems to sleep. They also have properties for Chinese
medicine, and are given to people that are sick and recovering. But they
lose vitamins or I don't remember what.

Are you quite sure the roast lowers the caffeine (teine) level? That
would
be good news for people, like me, who are supposed to cut down.


Well, I'm not a chemist, but - oh, wait a minute, I am one after all!
Caffeine has a listed sublimation point of 178 C. That's not a precise
number like a boiling point; it's where a heated sample of the pure compound
starts to evaporate (without melting) very quickly. As folks in northern
climes know, snow disappears even at -20 C, so the real question is one of
vapor pressure at more moderate temperatures. Another point to recognize is
that a substantially dry material like tea can be heated to way over 100 C;
it's probably reaching at least 250 C in the roaster. Hence the destruction
of delicate, health-giving organics - and the creation of new flavors. So
given free air exchange, the tea might be almost completely decaffeinated in
a minute or so.

I've thought of roasting tea at home, especially as I've got half a pound of
stale gunpowder green that wasn't very good in the first place. Anyone other
equipment/procedure recommendations? I was going to use either a
toaster-oven or a heavy frying pan, as some use for home-roasting green
coffee beans.

-DM

Kuri and Michael wrote:
Recently I bought a hand held, hemispheric, handled, unglazed ceramic
"roaster" which I use to roast a half ounce of tea at a time by holding
the
roaster over a flame and turning constantly. I've been enjoying this since
there are indeed changes that occur with my additional roast.
Not all oolongs are roasted. You can roast your tea yourself at home
(it's a
good way to recycle greens that are getting a bit old) to see the
effect.
....
About the health point of view. I don't have the reference here, but
roasting tea make it lose some exciting substances like cafeine/theine,
so
roasted teas can be better for children or to drink in the evening if
you
fear to have problems to sleep. They also have properties for Chinese
medicine, and are given to people that are sick and recovering. But they
lose vitamins or I don't remember what.

Are you quite sure the roast lowers the caffeine (teine) level? That
would
be good news for people, like me, who are supposed to cut down.


Well, I'm not a chemist, but - oh, wait a minute, I am one after all!
Caffeine has a listed sublimation point of 178 C. That's not a precise
number like a boiling point; it's where a heated sample of the pure compound
starts to evaporate (without melting) very quickly. As folks in northern
climes know, snow disappears even at -20 C, so the real question is one of
vapor pressure at more moderate temperatures. Another point to recognize is
that a substantially dry material like tea can be heated to way over 100 C;
it's probably reaching at least 250 C in the roaster. Hence the destruction
of delicate, health-giving organics - and the creation of new flavors. So
given free air exchange, the tea might be almost completely decaffeinated in
a minute or so.

I've thought of roasting tea at home, especially as I've got half a pound of
stale gunpowder green that wasn't very good in the first place. Anyone other
equipment/procedure recommendations? I was going to use either a
toaster-oven or a heavy frying pan, as some use for home-roasting green
coffee beans.

-DM

"Dog Ma 1" (reply w/o spam) wrote in message

Well, I'm not a chemist, but - oh, wait a minute, I am one after all!
Caffeine has a listed sublimation point of 178 C.
......
it's probably reaching at least 250 C in the roaster.

That was not that hot I think. I have measured and....sorry I don't
remember, . Well, I'll do it again.

I've thought of roasting tea at home, especially as I've got half a pound
of
stale gunpowder green that wasn't very good in the first place. Anyone
other
equipment/procedure recommendations? I was going to use either a
toaster-oven

I have recipe that says 40 minutes to 1 hour at 100 degree C in a oven.
Maybe the length has the same effect as the higher temp.
I didn't try. I guess the taste is different than with a shorter skillet
roast.

or a heavy frying pan, as some use for home-roasting green
coffee beans.

A light one is better. I also roast green coffee, and the problem is the
same : you need to agitate the thing you roast to avoid scorching, with
coffee that can be done in a wok or a pan if you stir very quickly. But I
don't imagine stirring the tea leaves without crashing them. Agitating a
little pop-corn skillet (with a net-cover) is easier. There are people that
use a net basket and agitate it over the fire.

Maybe about 40 g is a good quantity.

Kuri

Kuri wrote:
it's probably reaching at least 250 C in the roaster.
That was not that hot I think. I have measured and....sorry I don't
remember, . Well, I'll do it again.

FWIW, it's not easy to get an accurate temperature measurement with this
kind of arrangement, unless one uses a low-mass sensor or an off-contact
infrared emissivity thermometer.

I have recipe that says 40 minutes to 1 hour at 100 degree C in a oven.
Maybe the length has the same effect as the higher temp.
I didn't try. I guess the taste is different than with a shorter skillet
roast.

By coincidence, I did part of my doctoral work on flash vacuum pyrolysis. I
was making delicate, unstable molecules that would be destroyed in a few
seconds of warming in solution. But with contact times of around a
millisecond, "cooking" at over 1000 C gave excellent yields.

Some reactions increase in rate exponentially with temperature, while others
increase more gradually or even slow down. Some reactions won't occur at all
below a threshold temperature. So just as with brewing parameters, roasting
at different time/temperature combinations to the same overall degree will
doubtless change the balance of flavors and aromas. I'll try the slow-roast
next. I had no problems with sticking, burning or breaking, but of course
gunpowder tea is already in neat pellets. A bold-leaf tea might be a little
more challenging, and better suited for the toaster-oven.

-DM

Michael & Kuri:

Sorry I mixed up your question, can you please tell me- what kind of
clarification you guyes are talking about? Thanks.

Ripon
Vienna,VA


Michael Plant wrote in message ...
/11/04


Hi,

Another question here about oolong teas that I'm hoping someone can answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston

Winston, you and I both could use some more clarification here. It appears
to me that if a tea is more heavily roasted, but not very highly oxidized,
it will appear quite dark as dry leaf, but become much greener in the water.
The taste will also be different. Oxidation and roasting are totally
different processes, in some sense diametrically opposed, I think, since
roasting should stop oxidation, and lead to taste differences. *Exactly*
what they are eludes me sometimes. That's why I too need a bit of
clarification.

Michael

Fun! At last, something to do with my stale greens to (hopefully) make them
usable, instead of throwing them out.

I remember home-roasting green coffee beans back in the day. Nothing better
(within the coffee world, that is).

Joe

Ripon,

I think I had the question: Could you tell us more about the difference
between traditional method and ancient China method? Also, what are the
names of the teas using the ancient China method and where can they be
purchased?

Sorry if I've mixed up the thread.

Winston

"Ripon" wrote in message
om...
Michael & Kuri:

Sorry I mixed up your question, can you please tell me- what kind of
clarification you guyes are talking about? Thanks.

Ripon
Vienna,VA


Michael Plant wrote in message
...
/11/04


Hi,

Another question here about oolong teas that I'm hoping someone can
answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors
note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly
oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more
oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston

Winston, you and I both could use some more clarification here. It
appears
to me that if a tea is more heavily roasted, but not very highly
oxidized,
it will appear quite dark as dry leaf, but become much greener in the
water.
The taste will also be different. Oxidation and roasting are totally
different processes, in some sense diametrically opposed, I think, since
roasting should stop oxidation, and lead to taste differences. *Exactly*
what they are eludes me sometimes. That's why I too need a bit of
clarification.

Michael

Ripon,

I think I had the question: Could you tell us more about the difference
between traditional method and ancient China method? Also, what are the
names of the teas using the ancient China method and where can they be
purchased?

Sorry if I've mixed up the thread.

Winston

"Ripon" wrote in message
om...
Michael & Kuri:

Sorry I mixed up your question, can you please tell me- what kind of
clarification you guyes are talking about? Thanks.

Ripon
Vienna,VA


Michael Plant wrote in message
...
/11/04


Hi,

Another question here about oolong teas that I'm hoping someone can
answer:

Is the roasting of oolong related to oxidation level?

For example, especially with China Ti Guan Yin, some packages/vendors
note
"medium roast", "dark roast", etc.
I was always under the impression that Ti Guan Yin was a lightly
oxidized
oolong. So, I'm wondering where a "dark roast" fits in - is it more
oxidized
that other Ti Guan Yins?

Thanks for any clarification.

Winston

Winston, you and I both could use some more clarification here. It
appears
to me that if a tea is more heavily roasted, but not very highly
oxidized,
it will appear quite dark as dry leaf, but become much greener in the
water.
The taste will also be different. Oxidation and roasting are totally
different processes, in some sense diametrically opposed, I think, since
roasting should stop oxidation, and lead to taste differences. *Exactly*
what they are eludes me sometimes. That's why I too need a bit of
clarification.

Michael