IKOMA, Nara Pref. -- "It is totally handmade and finely crafted work, but no matter how well it is made, chasen (a bamboo tea whisk) is a commodity with a limited life span," says Keizo Kubo, 59, who has been manufacturing the tea-ceremony utensil for 36 years.

"And it is because of that, that the chasen should be made to last, feel good in the hand and form a fine froth. You will find out how good our chasen are when you actually make green tea on a daily basis," said Kubo, who owns Chikusendo, a chasen factory, and who is a chairman of Takayama Chasen Production Cooperative.

Chasen is used in the tea ceremony to whip a mixture of green tea powder and hot water into froth. It is made of a piece of cut bamboo, about two-thirds of which is finely split with the tips slightly curled toward the center.

Takayama-cho in northern Ikoma is said to be the birthplace of chasen in the 15th century and it remains the main producing region in the country, with almost 99 percent of the market share and some 500,000 pieces produced annually.

The invention of the utensil is credited to one of the sons of the warlord Takayama Yorie, who later passed it on to 16 of his retainers. That same method of making the utensil has been passed down for generations and was never disclosed to people other than family members or relatives until the end of World War II, when that period's shortage of manpower forced things to change.

In the 1960s, as many as 60 factories were in operation but that number has since dropped to the current 24 members of the Takayama Chasen Production Cooperative and a few other non-members.

Now Kubo is worried that the number of people who practice tea ceremony or who drink green tea is falling. Besides that, the number of cheap chasen imported from South Korea and China has risen to between 300,000 to 400,000 annually.

But those who practice tea ceremony or who often make green tea at home continue to choose Takayama chasen for its quality, he said.

"A Takayama chasen lasts for one year and can make proper froth even after its original shape has changed, while imported ones are often not that strong and sometimes smell of chemicals," he said.

The difference stems from the process used before making the chasen itself. Bamboo is cut between November and February and boiled to remove excess oil. After drying for about a month in paddy fields, it is stored in warehouses for at least three years. During this period, low-quality bamboo is weeded out.

Imported chasen are made of bamboo which is used soon after it is cut down, Kubo explains.

Only three or four pieces are used from an entire bamboo stalk. First, the outer skin is peeled, then one end is split into 16 parts. Each of the 16 portions is then split into 10 parts before all the tips are sharpened.

All tips are squeezed and curled toward the center, and then interwoven with a thread at the base so that each stem alternates in and out.

Although each operation is equally important and difficult to master, Kubo said that the sharpening part called aji-kezuri is the most important because it determines the aji (taste) of the tea.

For Kubo, the most difficult part is to stay seated all day long.

"Because every bamboo piece is different in hardness, it has to be shaped by hand. And because it is very delicate work, I can make better ones some days than other days. I am still learning," he said.