The Japanese tea whisk, or chasen (茶筅) is used to mix and whisk finely milled green tea powder with the water into a frothing hot bowl of matcha.

Tea ceremony, made successful by Sen no Rikyu in the Anzuchi and Momoyama eras, was carried on by Sen no Rikyu's descendants after his death, and the Omotesenke, Urasenke and Mushanokojisenke schools. Other schools also formed. Different varieties of the Japanese chasen were designed depending on the purpose and tine count etc. prescribed by the school, and these varieties too expanded to become the over one hundred varieties that exist today.

Chasen diagrams and instructions from various tea schools and masters.  Photo: Tanimura Tango

Structure

The chasen is always made out of one single piece of bamboo, from which the craftsman hand carves the tips or tines. A knife is then used to tease off the tips into an elegant form and the whisks vary in size and shape.
Traditionally, the tea whisk is made out of bamboo harvested in winter and then dried for over a year. The bamboo is usually 2cm–2.5cm thick and 9cm–12cm long.

Being a relatively conservative industry, only a few artisans achieve the skill and meticulous finesse it takes to create a chasen whisk.

Click here to watch the creation of a chasen 

 

a) chajimi (ear) 茶じみ
b) hosaki (teeth) 穂先
c) karami-ito(string) 絡み糸 
d) jiku 軸 
e) fushi 節

 

How to select the proper chasen

The chasen, is usually made out of one of these types of bamboo:

• Aodake (青竹): fresh green bamboo, only December, not advisable to order from abroad because the colour deteriorates considerably). Used for ceremonies of the new year.
• Hachiku oder Awatake (淡竹): dried white bamboo, used by Urasenke School
• Susudake (煤竹): soot-colored by smoke, used by Omotesenke School
• Shikichu oder Kurotake (黒竹): black bamboo, used by Mushanokojisenke School

There are different whisk types, individually designed for thin or thick matcha, depending on the number and thickness of their tines (also prongs or bristles). The main types are:

• Chu-araho: a chasen type with 70 to 80 rough tines, a thick, dense ear at the head, used to whisk koicha (thick matcha) 
• Kazuho: a chasen type with up to 120 finer tines, a thin and sparse ear at the head, typically used to whisk usucha (thin matcha)

The expression "Shin" is also often used together with a chasen type. Shin is usually  translated as "formal". lt corresponds to the shape of a chasen used for formal gatherings in the Way of Tea. The tips of the tines are more rounded.

Other types exists also for special applications:

• Tenmoku Chasen: to use withTenmoku tea bowls
• Nodate Chasen: smaller chasen to use at outdoor tea gatherings
• Chabako Chasen: small, thin chasen for outdoor tea set in a box
• Kotobuki Chasen: with red and white string (or another color) instead of black, as a decorative detail associated with auspicious celebrations (eg: New Year's)
• Hana-chasen: this chasen has three rows of tines, so it can't be placed on the whisk stand. Its irregular shape is not suitable for the Way of Tea

 

Examples

	Kisen Chuaraho Chasen Made by Nakata Kizo in Takayama This chasen is used with by the Urasenke school for the preparation of Koicha.
	Takayama Kazuho chasen 120-Pondate Made by Kubo Sabun in Takayama. A favorite of the main Urasenke tea house, this kazuho is for use with usucha (thin tea).
	Takayama Shin Kazuho Chasen Made by Kubo Sabun in Takayama. The shin kazuho is a favorite of the main Urasenke school tea house. It can be used with usucha (thin tea) or koicha (thick tea). It is easy to use and durable.
	Takayama Chasen Susudake Bamboo Shin Made by Kubo Sabun in Takayama A chasen primarily used by the Omotesenke school in offerings, with "tenmoku" tea cups (tea cups with thin lips, in a style brought back from China by a monk in the Kamakura era). Tea offerings are ceremonies in which tea is reverently offered to gods, Buddhist deities and spirits of the deceased.
	Takayama Chasen Rikyu Made by Kubo Sabun in Takayama A chasen favored by the Urasenke school school and allegedly designed by tea ceremony master Rikyū, Usucha (thin tea) and koicha (thick tea) versions are both available styles such as the "Rikyū-gata" (利休形)or "Sen Rikyū model".
	Takayama Chasen Kankyu-An Made by Kubo Sabun in Takayama A chasen made of black bambo and used by the Mushanokojisenke school.

 

Taking care of your chasen

Chasen Reshaper Stand (Kusenaoshi)

 

The tines are fragile and can break easily. Careless treating may shorten its lifespan. Tea whisk is usually kept standing upright, in a tea ceremony as well.  Resting it on its tines may damage them.

Another tip is leaving the tea whisk in water for about 30 min before each use, if possible. Soaking will make it more elastic, less likely to break, and of course just last longer.

After use, wash it with water and air dry completely to prevent molding. Alternatively use a ceramic or china ware chasen stand (Kusenaoshi) to dry and reshape your whisk and avoid its tines loosing their wave-form. Store in a cool,​ ventilated place to ensure a long life.

Beware of cheap chasen from some countries possibly containing high quantities of toxic substances such as preservatives and anti-mold agents. If they are used in hot water, which is then ingested, they are not safe for the body. In Japan, however, after drying bamboo harvested in winter for over a year, no preservatives and anti-mold agents are used because this bamboo is intended to manufacture chasen.

Appearance of the bamboo can determine a higher price, for example dark ("smoked or sooted") bamboo used for specific schools of tea ceremony is more scarce; or the quality of the bamboo (whether it is grown in Japan or elsewhere, and how stiff it is).

Note:
Commonly the Japanese word for tea whisk is written with the two Kanji 茶= cha and 筅= sen. It is only in Takayama (Nara prefecture) that the Kanji 筌 for sen is used.

Sources:
www.yuuki-cha.com/teaware/matcha-accessories/
www.readcereal.com/chasen-the-bamboo-whisk/
www.everyonestea.blogspot.ch
www.mizubatea.com/blogs/news/
www.studiokotokoto.com/2014/04/29/
www.marukyu-koyamaen.co.jp
www.jcrafts.com
www.maikoteashop.com
www.charaku-tea.com
www.aisf.or.jp/~jaanus/deta/c/chasen.htm