Kama

The kama is frequently confused with the tetsubin (see Tetsubin), but these are distinct objects with different functions: the kama is a ceremony kettle that sits directly over a heat source inside the tea room and from which hishaku (bamboo ladle) draws water; the tetsubin is a pouring kettle brought to the tea table. The kama never has a spout (water is drawn from it by the hishaku, not poured), and it is never removed by hand during the ceremony — to move a hot kama by hand would require the creased cloth pad, the futaoki (lid rest), and careful choreography. The kama’s sound — the sound of water nearing a simmer, described as wind passing through pine trees — is itself considered an aesthetic element of the tea room.

In-Depth Explanation

Structural Characteristics

A kama is distinguished from other iron kettles by:

1. Absence of a spout:

Unlike the tetsubin, the kama has no spout. All water is accessed via the futa (lid), removed with the hishaku (bamboo ladle) or the futaoki (lid rest). Water is ladled with the hishaku, never poured. This is an absolute distinction from the tetsubin.

2. Lugs (鐶付, kannetsuki):

Most kama have two small iron loops or lugs (kannetsuki) on either side of the body. These are for carrying the cold kama with iron rings (kan) — never handled during the ceremony. The lugs and their decorative treatment are often the most refined element of the kama’s surface design.

3. Surface texture:

Traditional kama surfaces are characteristically textured rather than smooth. Common textures include:

Arare (霰): Hammered dot pattern resembling hailstones — the most common and conservative texture
Nishiki (錦): Woven/lattice pattern
Fushi (節): Bamboo-node-inspired
Karahana (唐花): Tang-flower arabesque

The texture both aesthetically elevates the object and provides functional grip.

4. Lid (蓋, futa):

The removable lid sits atop the kama. Its material (iron, clay, bronze), underside design, and the handle (tsumami) are refined elements. Lids rest on the futaoki (見台, a small stand made of bamboo, ceramic, or metal) when removed.

Heat Sources: Furo and Ro

The kama is used with one of two heat sources depending on the season:

Furo (風炉) — summer brazier:

A portable charcoal brazier, typically ceramic or metal, placed in the tokonoma or on the tatami floor
Used from April through October (warm months)
The furo is brought in and out; the kama sits in it

Ro (炉) — sunken hearth:

A square cutout in the tatami floor, lined with clay, in which charcoal is burned
Built into the tea room floor; fixed infrastructure
Used from November through March (cold months)
The kama sits in the ro opening; the heat fills the room subtly
The ro’s position and the ritual of ro-biraki (opening the ro for the first time in November) mark a major seasonal transition in the tea calendar

The shift from furo to ro season is one of the central temporal structures of chanoyu. Different kama designs are conventionally appropriate to each season: lighter, smaller kama for summer/furo; heavier, larger or more rounded kama for the ro.

The Sound: Matsukaze

The sound of the kama simmering — water heated but not boiling, producing a gentle hissing and rushing sound — is described in Japanese tea aesthetics as matsukaze (松風): “wind through pines,” comparing the sound to the sighing of wind through a pine forest.

Achieving the correct matsukaze sound requires:

Correct water temperature: Near a simmer, not boiling. Boiling produces rolling bubbles and a harsher, louder sound. The ideal temperature for matcha preparation (approximately 70–80°C) is approached from below, maintained, and the kama sound reflects this controlled preparation.
Correct charcoal arrangement: The charcoal procedure (sumidemae) that arranges charcoal precisely in the furo or ro is itself a full component of tea ceremony, performed as an aesthetic ritual in its own right. Proper charcoal arrangement ensures even, controlled heat that produces the simmering state.
Kama design: Different kama designs and wall thicknesses produce subtly different sounds. Connoisseurship in kama selection includes assessment of the sound quality produced.

Matsukaze is described in the Nanporoku (南方録), the foundational text of Rikyu aesthetics, as one of the presences that gives the tea room its quality: silence is only possible against the backdrop of the kama sound.

Production: Regional Traditions and Masters

Iron kama production is concentrated in specific Japanese regions and has been closely associated with the major tea schools’ patronage:

Kyoto kama:

Nishimura (西村) tradition: Kyoto-based; associated with Omotesenke and Urasenke school patronage from the Edo period; typically elegant proportions; refined arare or classical surface textures.

Tenmyō (天明) kama:

From Sanotenmyō (栃木県佐野市); the name refers to the town of Sano, historically called Tenmyō. Considered the oldest and most historically important kama production center; robust, deeply textured surfaces; associated with the Wabi aesthetic; made from an iron ore deposit in Tochigi Prefecture. The term “Tenmyō kama” is now applied broadly to kama in this traditional style, even when not made in Tochigi.

Ashiya (芦屋) kama:

Historically from Ashiya, a port town in what is now Fukuoka Prefecture; considered by many historical tea masters the finest kama tradition; production ended in the Edo period (17th–18th century), making genuine Ashiya kama extremely rare antiques. Known for refined, elegant proportions and exceptional surface decoration quality. The rarity of genuine Ashiya kama has made them among the most valuable tea objects at auction.

Care and Maintenance

A kama used regularly requires care to prevent rusting and maintain the interior condition:

New kama preparation: A new iron kama requires seasoning (similar to cast iron cookware): boiling water several times to release industrial residues and develop a light interior patina before use for matcha
Drying after use: After the ceremony, residual water is dried by placing the kama back over low heat briefly; never stored while wet
Not washing with soap: The interior develops a protective mineral/oxidation layer from water minerals over time; washing destroys this
Long-term storage: Dry completely; store in a breathable bag or box; no moisture contact

Over decades of regular use, a kama develops an interior mineral deposit from the water used in it — considered evidence of lineage and use, not a defect. The mineral layer also affects the water’s taste subtly, contributing to the patinated qualities of well-used equipment.

Common Misconceptions

“Kama and tetsubin are the same thing.” They are closely related iron vessels but functionally distinct: kama are for ceremonial use over a heat source with no spout; tetsubin are for table use with a spout for pouring. Using a tetsubin as a kama (or vice versa) is incorrect procedure.

“The kama is moved during the ceremony.” A heated kama is never moved by hand during the ceremony. The choreography of chanoyu assumes the kama’s fixed position relative to the practitioner. Even removing the lid (futa) follows a precise sequence using the hishaku handle and the futaoki.

“Modern electric kama are equivalent.” Electric kama exist and are used for training and informal practice by beginners. However, charcoal-over-clay-lined-ro or furo produces a different heat — radiant infra-red from charcoal — that affects water differently than electric elements. More significantly, the ritual of sumidemae (charcoal procedure) is itself a component of formal tea ceremony, making the heat source part of the practice, not merely functional.

Related Terms

Research

Varley, P., & Kumakura, I. (Eds.). (1989). Tea in Japan: Essays on the History of Chanoyu. University of Hawaii Press. The standard English-language scholarly compilation on chanoyu history; contains multiple essays directly addressing the technical and aesthetic development of iron kettle (kama) production traditions, including the distinction between Ashiya and Tenmyō production centers, the role of San’ami and the Higashiyama aesthetics circle in elevating kama appreciation, and the relationship between Rikyu’s aesthetic values and kama design preferences; primary source for the historical periodization and school-patronage relationships discussed in this entry.
Sen, S. (1998). The Japanese Way of Tea: From Its Origins in China to Sen Rikyu. University of Hawaii Press. Overview of chanoyu development emphasizing the Rikyu lineage; specifically addresses the role of sound (matsukaze) as an aesthetic element in the formative texts of wabi-cha; the Nanporoku passages on the kama’s presence in the tea room are cited and contextualized; addresses how Rikyu’s use of humble Tenmyō-style kama rather than ornate Ashiya pieces embodied the wabi aesthetic — a key art-historical point about kama selection as aesthetic philosophy.