It All Begins with the "Clay" Resting in the Land of Shigaraki

The journey of creating Shigaraki ware begins with its raw material: clay. This high-quality clay, the very lifeline of Shigaraki pottery, is excavated from a stratum called the "Ko-Biwako-sōgun" (Old Lake Biwa Group). This layer was formed some 4 million years ago when the Shigaraki region lay at the bottom of a massive lake.

However, the clay isn't used straight from the ground. One of the most fascinating steps is the "blending" process, where artisans masterfully combine several clays with different properties, tailored to the specific piece they intend to create.

The primary components are "Kibushi nendo" (a highly plastic clay rich in organic matter like plant fossils, making it easy to shape) and "Gairome nendo" (a fire-resistant clay containing coarse particles of quartz and feldspar, which acts as the piece's structural backbone). These clays are mixed and then repeatedly kneaded in a machine called a "dorenki" (pug mill) to remove air pockets and achieve a uniform consistency. This process, known as "tsuchi-neri" (clay kneading), is crucial as it determines the quality of every subsequent stage. Indeed, it is this masterful blending that lies at the heart of Shigaraki ware's versatility, achieving both the strength needed for large-scale works and the suppleness required for delicate forming.

Giving the Clay Its "Form": A Variety of Shaping Techniques

Once perfectly kneaded, the clay moves on to the "forming" stage, where it is finally given the shape of a vessel. Here again, a variety of techniques are chosen depending on the piece being made.

The most iconic method is undoubtedly wheel-throwing. Watching an artisan center a spinning lump of clay on a wheel (`rokuro`) and deftly pull it upward is to witness true mastery at work. Symmetrical, circular pieces like tea bowls, jars (`tsubo`), and vases are made using this technique.

Meanwhile, for asymmetrical shapes or large works like washbasins that can't be made on a wheel, techniques known as "tebineri" (hand-building) are employed. This includes methods like "himo-zukuri" (coiling), which involves stacking rope-like coils of clay. This technique is known for the warm, gentle undulations and unique character that only handwork can produce. Other methods, such as "tatara-seikei" (slab building)—joining flat sheets of clay—and "kata-zukuri" (molding)—pressing clay into a plaster mold to create uniform shapes—are used for specific items like square plates or the famous tanuki raccoon dog figurines.

After shaping, when the clay is "leather-hard" (`namagawaki`), the "kezuri" (trimming) work begins. This involves carving out the `kōdai` (the foot ring at the base of the piece) and refining the overall form. Artisans must precisely calculate the final dimensions from the start, as the clay will shrink by about 13% during the drying and firing processes.

The Quiet Time Before Firing: Drying and Bisque Firing

Once shaped, the piece heads into the "drying" stage to completely remove all internal moisture before it's placed in the kiln. If this step is rushed or overlooked, the intense heat of the final firing will cause the moisture to evaporate rapidly, leading to the piece cracking or breaking. To prevent this, the piece must be dried slowly and evenly in a well-ventilated, shaded spot over a long period, from several days to several weeks. Patience at this stage is the key to success later on.

Once bone-dry, the piece moves on to a process called "bisque firing" (suyaki). This is a preliminary firing at a lower temperature than the final one, around 700°C to 800°C. Bisque firing makes the clay porous, which increases its strength and makes it easier to handle. It also has the advantage of simplifying the subsequent glazing process. Furthermore, it reduces the risk of damage during the main firing, making it a critical preparatory step for a flawless finish.

The Climax: The "Scenery" Born from a Dialogue with Flame

After all the prep work, the piece finally reaches the grand finale of the entire process: the "main firing" (honyaki). Here, the piece is fired at scorching temperatures reaching from 1200°C to over 1300°C. This is the most crucial moment, the one that defines the unique character of Shigaraki ware.

The environment of this main firing dramatically influences the final "expression" of the vessel. In traditional wood-fired kilns like the "noborigama" (climbing kiln) and "anagama" (tunnel kiln), ash from the burning wood settles onto the pieces. At high temperatures, this ash melts and reacts with the clay's components, creating beautiful, glassy patterns. This effect is called "shizen'yu" (natural ash glaze) or "biidoro-yu" (vidro glaze), an art form created by flame, earth, and ash that goes beyond human intention. The firing can last for several days, with artisans working in shifts around the clock, continuously feeding wood into the kiln while reading the weather and the "mood" of the flames. No two pieces ever come out the same. This element of surprise is the real magic of a wood-fired kiln, and it breathes a one-of-a-kind life into each vessel.

On the flip side, the gas and electric kilns that power modern pottery production allow for precise temperature control, making them ideal for mass-producing items with stable quality. They're indispensable for items like tableware that need a consistent finish, but they are less likely to produce the dramatic "yohen" (unexpected transformations in the kiln) that wood-fired kilns are famous for.

What's more, the choice of "firing method," which involves adjusting the amount of oxygen in the kiln, also significantly affects the color. In "oxidation firing" (sanka shosei), where plenty of air is sent into the kiln, the iron in the clay combines with oxygen to create the warm red and orange "hiiro" (fire color) characteristic of Shigaraki ware. Conversely, in "reduction firing" (kangen shosei), which restricts the air supply, the flame undergoes a reaction that strips oxygen from the clay body. This causes the hiiro to take on a duller hue, and a blackish-brown "koge" (scorching) appears on the parts buried in the wood ash. Through this meticulous control of the firing, a process that could be called a dialogue with the flame, a rich and varied "scenery" is painted across the vessel's surface.

Unloading the Kiln, and the Birth of a "Vessel"

Even after the main firing is over, the kiln door can't be opened right away. A sudden temperature change could cause the pieces to crack or shatter, a phenomenon known as "kamaware" (kiln-cracking). After several days of slowly cooling the kiln, it’s finally time for the "kamadashi," or the grand unloading of the kiln. Each piece taken from the kiln is carefully inspected by the artisan's discerning eye. After undergoing final touches like polishing to smooth the base, it's finally ready to be called a finished product.