Do you know that tap water is potable in Japan?
In restaurants or cafes, a glass of water is served as soon as you take your seat.
Of course, it’s for free.
Also in some restaurants or cafes, a cup of tea is served as soon as you take your seat.
Don’t worry. It’s also for free.
This story tells us that tea is indispensable in our daily life as well as water.
By the way, do you know what makes Japanese tea different from other tea leaves, such as black tea or oolong tea?
1. What’s the difference?
Both black tea and Japanese tea derive from the same tea plant (Camellia Sinensis).
What makes Japanese tea different from other tea leaves is its process of fabrication.
That is to say, the difference arises depending on the 1) degree of oxidation and 2) method to heat the leaves.
Let’s look more concretely.
1) degree of oxidation
Firstly, the degree of oxidation.
Different from other tea leaves, green tea has no oxidation process.
- full oxidation ⇒ Black tea
- semi- oxidation ⇒ Oolong tea
- light- oxidation ⇒ White tea
- without oxidation ⇒ Green tea
- By oxidation, catechins in tea leaves change into thearubigin or theaflavin which is the origin of redness of the black tea (which we call red tea in Japan) .
- Catechin is a kind of polyphenol that makes the tea taste bitter and astringent.
Because of its low content rate of catechins, general tea leaves produced in Japan are not good for Black tea.
2) method to heat the leaves
Secondly, the method to heat the leaves.
Heating prevents oxidation of tea leaves by deactivating enzymes in them.
Based on its difference, we classify the green tea into two:
A) pan-fired tea (mainly produced in China and Taiwan),
B) steamed tea (mainly produced in Japan).
A) has a slightly sweet, roasted aroma, whereas B) has a fresh aroma and strong umami.
To sum up, most Japanese teas are steamed green tea.
But by reprocessing them, we make different types of teas (reprocessed teas).
2. Conpounds and Efficacy
The main characteristic of Japanese tea is in its compounds and efficacy.
Catechin is a polyphenol which is behind bitterness and astringency of the Green tea.
It brings some merits to our body.
– increase fat metabolism in hepatic cell
– anti-bacterial effect
– anti-oxidant effect (slow down aging process and prevent the formation of cancer cells)
– anti-allergic effect
L-theanine is a main compound behind the umami sensation.
It promotes alpha wave activity in the brain and make us relax.