Isn't that when you've drunk too much Gyokoro?Oni wrote:Gyomatoes are the best.
Maybe southern is sweeter
First guess is that the sweetness is related to carbohydrate content, specifically to polysaccharides and maybe monosaccharides (induced under specific conditions). So I went looking for info on these sugars in green teas. The Japanese and Chinese have been cranking out pretty interesting green/oolong/puerh tea papers lately.
Simple sugars aren't just building blocks for carbohydrates that make up plant cell wall as complex polysaccharide polymers. Total extractable sugars were found to consist of arabinose:glactose:glucose in a ratio of 1:1:0.5.
A rapid quantitative method for polysaccharides in green tea and oolong tea. European Food Research and Technology (2008)
http://www.springerlink.com/content/n800644l156176v7
Arabinose isn't just sweet. It happens to block sucrose uptake/transport in sap sucking insects, so it has insecticidal activity.
https://ars.usda.gov/research/publicati ... 82004&pf=1
Monosaccharides and some short polysaccharides do something else, though: they reduce dessication under dry weather conditions. Not only do plants use this trick to avoid cell disruption, so do bacteria and even some higher animals, like fish (they use sugar alcohols to keep from freezing in polar waters).
Maybe sweetness is associated with heat or water stress tolerance in tea cultivars. The further south you are, the longer the growing season.
The thickness and creaminess of matcha and theanine content of Japanese teas are exceptional. I'm willing to bet is associated with two factors: sulfur content of soils and environmental oxidation potential. Japan is a volcanic island arc. Maybe tea plants have adapted to these rich acid soil by taking up sulfur and nitrogen to form amino acids in roots that protect against acidic environmental conditions - they function as antioxidants, important when you're growing at higher (and dryer) altitude in thin air.
Prefecture topology, volcanic soil chemistry, local pests, coastal climate (including cloudiness/time of day, precip type, interaction with sea salt sulfates/nitrates and ozone, and altitude and latitude) with respect to specific Japanese cultivars will determine flavor/aroma and probably rheology (matcha viscosity and flow properties) of these teas.
Smoothness is probably a function solely of tea processing, especially oxidation control.
Simple sugars aren't just building blocks for carbohydrates that make up plant cell wall as complex polysaccharide polymers. Total extractable sugars were found to consist of arabinose:glactose:glucose in a ratio of 1:1:0.5.
A rapid quantitative method for polysaccharides in green tea and oolong tea. European Food Research and Technology (2008)
http://www.springerlink.com/content/n800644l156176v7
Arabinose isn't just sweet. It happens to block sucrose uptake/transport in sap sucking insects, so it has insecticidal activity.
https://ars.usda.gov/research/publicati ... 82004&pf=1
Monosaccharides and some short polysaccharides do something else, though: they reduce dessication under dry weather conditions. Not only do plants use this trick to avoid cell disruption, so do bacteria and even some higher animals, like fish (they use sugar alcohols to keep from freezing in polar waters).
Maybe sweetness is associated with heat or water stress tolerance in tea cultivars. The further south you are, the longer the growing season.
The thickness and creaminess of matcha and theanine content of Japanese teas are exceptional. I'm willing to bet is associated with two factors: sulfur content of soils and environmental oxidation potential. Japan is a volcanic island arc. Maybe tea plants have adapted to these rich acid soil by taking up sulfur and nitrogen to form amino acids in roots that protect against acidic environmental conditions - they function as antioxidants, important when you're growing at higher (and dryer) altitude in thin air.
Prefecture topology, volcanic soil chemistry, local pests, coastal climate (including cloudiness/time of day, precip type, interaction with sea salt sulfates/nitrates and ozone, and altitude and latitude) with respect to specific Japanese cultivars will determine flavor/aroma and probably rheology (matcha viscosity and flow properties) of these teas.
Smoothness is probably a function solely of tea processing, especially oxidation control.
.I wondered what caused certain green teas to have a pronounced sweet taste. This quality may be intensified by tea processing, could be tea variety- or location-specific. It would be desirable to have a natural sweetness that easily dissolves into infusion water to counter early eluting bitterness (caffeine).
Plants like sweet grasses and sweet potato produce arabinose, a simple sugar, to prevent aphid (white fly) attack. Seemed possible that green tea might also use arabiose and other sugars for another purpose - like preventing cells from losing water during dry periods.
Tea is unique in it's content of theanine. It's present as part of a series of stepwise reactions that allows cells to incorporate and convert ammonia soil nitrogen into key amino acids. In tea, stored forms of nitrogen include glutamine, glutamate and arginine, produced in roots and mobilized to leaves during growth. A related amino acid, proline, also appears to play a role in heat and water stress situations; its produced from glutamine.
Nutrient-rich soils encourage nitrogen uptake and accumulation in plants. Rich volcanic soils are abundant in Japan, but also found in China.
http://en.wikipedia.org/wiki/List_of_volcanoes_in_China
Glutamine can be converted to glutamic acid (glutamate) enzymatically and is identified as the flavor umami, a brothy or thick-tasting quality readily identified with some teas.
In higher lifeforms, glutamate acts on nerve cells as an exciter or activator. Caffeine is also an nervous system activator; the natural counter in green tea is theanine and GABA, nervous system inhibitors. Exciters and inhibitor concentrations can be manipulated through genetics, soils and climate, and cultivation practices. Maybe their ease of extraction is also enhanced through leaf processing steps.
So certain taste qualities are associated with important plant chemistry, much of it keyed to cellular response to stress. Sulfur metabolism, like nitrogen, also plays a key role in amino acid synthesis and stress response.
Seemed like a no-brainer to link differences in flavors to subtype and cultivar genetics, induction of cell response to growth conditions (climate, pathogens, soil fertility and plant culture).
As I mentioned, the Japanese and Chinese have put quite a bit of effort into study of tea plant chemistry, and that provides a handy information source to go looking for possible causes of desirable flavors and infusion broth physical qualities arising from leaf processing.
Plants like sweet grasses and sweet potato produce arabinose, a simple sugar, to prevent aphid (white fly) attack. Seemed possible that green tea might also use arabiose and other sugars for another purpose - like preventing cells from losing water during dry periods.
Tea is unique in it's content of theanine. It's present as part of a series of stepwise reactions that allows cells to incorporate and convert ammonia soil nitrogen into key amino acids. In tea, stored forms of nitrogen include glutamine, glutamate and arginine, produced in roots and mobilized to leaves during growth. A related amino acid, proline, also appears to play a role in heat and water stress situations; its produced from glutamine.
Nutrient-rich soils encourage nitrogen uptake and accumulation in plants. Rich volcanic soils are abundant in Japan, but also found in China.
http://en.wikipedia.org/wiki/List_of_volcanoes_in_China
Glutamine can be converted to glutamic acid (glutamate) enzymatically and is identified as the flavor umami, a brothy or thick-tasting quality readily identified with some teas.
In higher lifeforms, glutamate acts on nerve cells as an exciter or activator. Caffeine is also an nervous system activator; the natural counter in green tea is theanine and GABA, nervous system inhibitors. Exciters and inhibitor concentrations can be manipulated through genetics, soils and climate, and cultivation practices. Maybe their ease of extraction is also enhanced through leaf processing steps.
So certain taste qualities are associated with important plant chemistry, much of it keyed to cellular response to stress. Sulfur metabolism, like nitrogen, also plays a key role in amino acid synthesis and stress response.
Seemed like a no-brainer to link differences in flavors to subtype and cultivar genetics, induction of cell response to growth conditions (climate, pathogens, soil fertility and plant culture).
As I mentioned, the Japanese and Chinese have put quite a bit of effort into study of tea plant chemistry, and that provides a handy information source to go looking for possible causes of desirable flavors and infusion broth physical qualities arising from leaf processing.
Last edited by Intuit on Jul 14th, '09, 12:33, edited 1 time in total.
A telling comment
"In its wild state, tea grows best in regions that are warm and humid, with a rainfall of at least 100cm (39 inches) a year. It likes deep, light, acidic and well-drained soil. The volcanic soil often found at higher altitudes enhances quality"
"Careful selection for taste rather than yield, resistance to disease, or increased hardiness is the hallmark of gourmet speciality tea producers at this stage."
Interesting article.
http://www.steenbergs.co.uk/article/sho ... processing
"Careful selection for taste rather than yield, resistance to disease, or increased hardiness is the hallmark of gourmet speciality tea producers at this stage."
Interesting article.
http://www.steenbergs.co.uk/article/sho ... processing
Jul 25th, '09, 01:39
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Maitre_Tea
Re: Uji, Yame and Shizuoka -- Tastes different?
How does Kagoshima compare with these three? From what I've read, a lot of people rave about Sencha from Kagoshima. Chip's favorite, Yutaka Midori, is from this region (if I'm not mistaken). Is it the warm weather, or is it something else?
Jul 25th, '09, 02:01
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Re: Uji, Yame and Shizuoka -- Tastes different?
It is not so much a matter of Kagoshima tasting a particular way, it is a combination of factors including the warmer climate making it conducive to growing some more exotic varieties such as Yutaka Midori, Okumidori, Asatsuyu, etc. They also seem willing to experiment with manufacturing techniques that perhaps more stoic and tradtional Uji manufacturers seem to have little use for.Maitre_Tea wrote:How does Kagoshima compare with these three? From what I've read, a lot of people rave about Sencha from Kagoshima. Chip's favorite, Yutaka Midori, is from this region (if I'm not mistaken). Is it the warm weather, or is it something else?
There are great teas coming from the big 3 (4 including Yame) sencha prefectures. There are bad ones as well.
I was not only enamored by Yutaka Midori from O-Cha, but also the elusive nature of Kagoshima teas up to a couple years ago.