Raku pottery was made long ago for Japanese tea ceremonies. It was modernized later into the process you see today. This involves taking a piece of pottery that has been bisque fired and glazed then firing it in a raku kiln (which my husband and I built ourselves). The piece is then fired to about 1800 degrees F and pulled out of the kiln while still red hot then placed in a reduction chamber containing organic materials such as newspaper, sawdust, leaves, etc.