I make my pottery in Vienna my home, and others make their pottery in their home, and sometimes our paths cross. This a time, this a crossing: my second firing of the anagama woodfired kiln at Atelje Janja Gora, Croatia. I the American living in Austria, firing with others from Slovenia, Croatia, and Taiwan.
We fired for a total of 39 hours, and reached a max of 1293°C. The kiln was packed tightly, very tightly, making it difficult to attain and maintain these highest temperatures. Whereas with other firings it was possible to go from 1200° to 1350°+ without so much as looking at the kiln (perhaps not looking was the trick), with this one we struggled for tens of hours to get just 100 degrees higher. But in a way, better: a longer firing leads to more wood ash building up on the pots, and beautiful wood ash is the hallmark of an anagama kiln.
Not a single piece glazed (I learned from my mistakes last time I fired at this kiln), the clay will develop a color and texture all its own from the path the fire weaves through the kiln. Fire is wood ash, physical objects burning themselves away, and as it lands on pots it sticks to the pots and melts to the pots, yes please.
Anja Slapnicar, at the left, has fired this kiln some 10 times. Branko Šupica, at right, built the kiln in 2013.
Liank Wu here, a Taiwanese potter under whom Anja spent some time working. Wu himself works under (for 19 years, he says) the potter Lin Jui-Hwa: the potter who set the Guinness world record for highest temperature in a wood-fired kiln i.e. 1563°C. Sure there are some potters who fire to such temperatures without needing a Guinness team (sometimes without needing a pyrometer), Kumano Kuroemon comes to mind, but still.
Inside that kiln there is 1200+ degrees C and a meter or two away you’re drinking water trying to stay slightly cooler. The kiln’s walls are thick, thick helps insulate in a way but also maintains temperature. Once it starts getting hot, it starts staying hot. Cooling down takes a good 7 days, from 1200 to 20ish.
Black smoke, reduction, when the kiln’s atmosphere is deprived of oxygen. Fire needs oxygen to breath, so given said dearth it starts to suck it from the pots: the oxides in the glaze, and in the body. This causes deliciously irreversible changes in both glaze and body: a glaze what with enough oxygen will look glossy jade green in reduction turns a blood red, for example.
Kilns often move between oxidation, saturated with oxygen, and reduction; a good firer knows 1. which atmosphere is appropriate for the works inside 2. how to get that atmosphere 3. when to get that atmosphere. Some glazes need reduction, some glazes need capital-R Reduction, some clay bodies need reduction, some need capital-R reduction; sometimes, like this time where we used no glazes on the pots, reduction happens but it isn’t a goal.
And it’s done. The kiln signed and sealed, the pieces waiting till the opening and the delivery.