Found this interesting article on coffee:

http://news.yahoo.com/s/livescience/...escoffeebitter

It basically identifies two components that make coffee bitter, both
due to roasting. My thoughts a does tea that is roasted longer
taste comparatively bitter? (I say comparative b/c you can probably
always brew in such a way as to reduce bitterness). I have a pretty
seriously roasted Tie Guan Yin that may fit that bill, but I've also
tried some green pu-ers where bitterness seems to dominate (I don't
think pu-er is really roasted, is it?) Second: is bitter something we
would want to get rid of anyway? I kind of like a bitter edge
sometimes. I try to keep it at the edge, but I think bitterness can be
a good thing. I wonder if changing coffee brewing parameters would
reduce bitterness--looks like they tested the brew rather than the
bean here.

Just thoughts, nothing more. . .

C

On Aug 22, 2:20 am, cha bing wrote:
Found this interesting article on coffee:

http://news.yahoo.com/s/livescience/...ence/chemistsf...

It basically identifies two components that make coffee bitter, both
due to roasting. My thoughts a does tea that is roasted longer
taste comparatively bitter? (I say comparative b/c you can probably
always brew in such a way as to reduce bitterness). I have a pretty
seriously roasted Tie Guan Yin that may fit that bill, but I've also
tried some green pu-ers where bitterness seems to dominate (I don't
think pu-er is really roasted, is it?) Second: is bitter something we
would want to get rid of anyway? I kind of like a bitter edge
sometimes. I try to keep it at the edge, but I think bitterness can be
a good thing. I wonder if changing coffee brewing parameters would
reduce bitterness--looks like they tested the brew rather than the
bean here.

Just thoughts, nothing more. . .

C


Both interesting and thought provoking.

The threshold reaction to Bitter taste appears to be much lower in the
USA than Europe. Robust CTC teas are the most popular in Britain but
the lighter more mellow orthodox teas are preferred in the USA. An
English Breakfast tea is principally blended from East African CTC
teas that we with enthusiasm would say are pungent and astringent but
are disliked in the New World as being too bitter. Sweet tea so
popular in the US south, and tea bag tea generally, based on almost
tasteless non bitter South American orthodox teas, is anathema to most
of us over here. The cultural acceptance in the USA of black teas
brewed in below boiling water I believe is due to this method
resulting in a less bitter liquor. With the exception of the
excellent micro brewery beers I suspect that American commercial beers
(Lites!) have the same lack of bitterness compared to European
preferred brews - the standard beer of Britain is even ordered as "a
pint of Bitter ".

However, bitterness in tea derives from different sources than in
coffee. Coffee is roasted at a much higher temperature than is any
tea. Product temperature (in the bean) will reach well above 200
degrees C when pyrolysis occurs - a heat producing (exothermic)
reaction breaking down carbon to CO2 that actually supplies 12% of the
energy required for the roasting. (Financially hard pressed tea
producers should be so lucky!) The pyrolysis products give the
typical brown color and roasted coffee aroma (nobody would choose to
drink coffee made from green coffee beans), but pyrolysis also
produces some very bitter compounds - and the higher the roast the
more there is of them. Normal teas are dried at the much lower
temperature of 95-105 degrees C and while some browning (and flavor
production) occurs in oxidised teas when sugars and amino acids react
(by heat induced Maillard reaction - similar to browning of roasting
meat) this in tea occurs sub 100 degrees C. The only teas dried much
above 100 deg C are the so called roasted ones - mainly some oolongs
and greens. Traditionally this is done in a charcoal fired wok and,
while the temperature of the wok surface is definitely very hot (I
have seen 160 deg C quoted) the actual leaf temperature is less than
this as it is constantly stirred and moved away from the hot metal.
As the leaf dries the temperature is reduced but is nevertheless is
hot enough to produce the roasted flavor - in those tea types where it
is required. In black tea too high a temperature is bad - called by
the tea maker "high firing" or "bakey" if only a touch high - and is a
character required in some teas - Darjeelings are typically high
fired. If too high it's termed "burnt" and value drops like a stone.
Chosen Oolongs are allowed the high fired character when it is called
"roasted" - but it does not I think impart any bitterness.

Nigel at Teacraft

Nigel, thanks for this. I agree that for the most part we Americans
deny ourselves the pleasure of one of the five basic tastes. Another
example, besides the ones you mention, is British marmalade (balanced
with notes of bitterness) vs. American (sweet-sweet). I think and hope
that we are gradually learning be[i]tter. In the meantime I've got my
India Pale Ale. (Real masochists can drink kuding.)

But isn't one reason for this difference the use of milk in Britain?
I don't usually like milk in my tea but when I drink the popular British
brands, or Barry's, brewed "strong enough to trot a mouse on" they just
seem to be made for a splash or two.

Best,

Rick.

In article .com,
Nigel wrote:

The threshold reaction to Bitter taste appears to be much lower in the
USA than Europe. Robust CTC teas are the most popular in Britain but
the lighter more mellow orthodox teas are preferred in the USA. An
English Breakfast tea is principally blended from East African CTC
teas that we with enthusiasm would say are pungent and astringent but
are disliked in the New World as being too bitter. Sweet tea so
popular in the US south, and tea bag tea generally, based on almost
tasteless non bitter South American orthodox teas, is anathema to most
of us over here. The cultural acceptance in the USA of black teas
brewed in below boiling water I believe is due to this method
resulting in a less bitter liquor. With the exception of the
excellent micro brewery beers I suspect that American commercial beers
(Lites!) have the same lack of bitterness compared to European
preferred brews - the standard beer of Britain is even ordered as "a
pint of Bitter ".

Nigel, Thanks so much for your post. I have been obsessed with
collecting this type of information lately. So I guess bitterness and
heat aren't really associated factors in tea. But I have also heard
that roasting tea makes it sweet in some respects. As I'm trying to
figure out how roasting affects a tea's taste, I wonder if you'd be
able to characterize what the "bakey" taste is like. Really, what I am
looking for is a description of a scale: at one end would be the no-
roast tea, and at the other would be the "bakey" or "burnt" tea. In
between would be something that is sweet? Maybe there are too many
other factors at play to be able to nail down this roasted flavor
without simply drinking lots of teas and seeing the differences for
myself.

cha bing

On Aug 24, 2:25 am, cha bing wrote:
Nigel, Thanks so much for your post. I have been obsessed with
collecting this type of information lately. So I guess bitterness and
heat aren't really associated factors in tea. But I have also heard
that roasting tea makes it sweet in some respects. As I'm trying to
figure out how roasting affects a tea's taste, I wonder if you'd be
able to characterize what the "bakey" taste is like. Really, what I am
looking for is a description of a scale: at one end would be the no-
roast tea, and at the other would be the "bakey" or "burnt" tea. In
between would be something that is sweet? Maybe there are too many
other factors at play to be able to nail down this roasted flavor
without simply drinking lots of teas and seeing the differences for
myself.

I will attempt to give you a scale but two caveats he words are
inadequate descriptors of the spectrum of tastes that can be found in
a tea cup. And many "good tastes" become bad when present to excess;
but excess varies widely for different people. Some will bridle at a
slight smokiness in a Yunnan while others cheerfully drink Lapsang
Souchong, the more tarry the better. Roasting is accepted in some
teas but is not in others, hence the degree and type of roasted flavor
can be positive or negative depending on your perspective.

In a well made Assam for instance there is a tendency to maltiness -
this is a flavor produced during drying (also known as firing and to
some as roasting). "Malty" is a sweet positive aroma/taste/flavor
(ISO term 2148 - a desirable characteristic in some teas that have
been fully fired, suggestive of malt or caramel). Slightly further
along the scale or spectrum is "biscuity" (ISO term 2108 - a liquor
having a characteristic reminiscent of biscuits (cookies)) - this is
also seen by some as acceptable in an Assam, though perhaps not in a
Ceylon. Bordering on either side of acceptability we have "fully
fired" (ISO term 2134 - describes the liquor of a tea which has been
slightly over fired during manufacture) and "high fired" (ISO term
2142 - describes the liquor of a tea which has had too much firing.
It is generally undesirable except in the case of certain Darjeelings
where it is a great asset). Into the really unacceptable flavor area
comes "bakey" (ISO term 2107 - an unpleasant characteristic noticeable
in liquors of teas which have been subjected to higher than desirable
temperatures during the firing (drying) operation) and "burnt" (ISO
term 2114 - an undesirable characteristic found in the liquor of teas
which have been subjected to abnormally high temperatures during
firing; a degree worse than "bakey"). Then we have "cooked" (ISO term
2124 - a liquor burnt to such an extent that all other tea
characteristics are hidden) - that's about a bad as it gets. Sweet
(though not really recognized as a tasting term) probably in the above
case tails off with high fired when bitterness creeps in - but again
beware, both sweet and bitter can be present to greater degrees due to
other factors than drying.

ISO tasting terms quoted from international standard ISO 6078-1982
Black Tea - Vocabulary, unfortunately ISO has not produced a standard
for green teas or oolongs

Nigel at Teacraft

Note that these positive characters merging into defects are due just
to a 10-15 degree F difference in dryer temperature.