Raku is a kind of low-fire pottery that is intended for decorative use. It will not hold liquids, and it’s not considered “food safe” because of the unglazed areas and the crackle glaze, which can trap bacteria.
You can, of course, use a raku bowl to hold loose change, dried flowers, etc.
How Raku Pottery is Made
|Soft clay is formed into the desired shape. This can be done by hand, or on a potter’s wheel. The work is then allowed to dry.
The pots are sometimes burnished at this stage with a smooth stone to create a polished surface.
|The work is fired in a kiln, to a temperature of approximately 1800° Fahrenheit, and allowed to cool. This produces a hard, durable form called bisqueware.
The bisqueware is then painted with special raku flazes, including underglazes to create colors, metallic glazes, and crackle glazes.
|The glazed pots are fired in raku kiln, again to temperatures in the 1800° range.
The kiln is opened while the pots are glowing hot. The thermal shock causes the crackle glaze to craze with a network of tiny cracks.
|Wearing protective clothing and using long tongs, the potter removes the pots from the kiln and places them into small cans filled with newspaper, sawdust, or straw. The combustible material instantly bursts into flame, and the can is then sealed.
This process removes the oxygen from the air within the can. As the pots cool, the metallic glazes remain bright and shiny, and the unglazed areas of the pot (including the cracks in the crackle glaze) absorb the carbon from the smoke and become black.
|Once the can is cool, the finished raku pot is removed, scrubbed clean, and sometimes sprayed with a protective lacquer coating to keep the metallic glazes shiny.