Kaibo (stirring paddle)

Kaibo (櫂棒) is a wooden tool used in sake brewing to stir the contents of the shubo (yeast starter) and moromi (fermentation mash). Wood is generally used, though bamboo is sometimes used as well. The most common type of kaibo is the kaburagai (蕪櫂), which has a wooden board attached to the end of a bamboo or wooden pole. There are various types according to length, including the ogai (大櫂) at about 2.3 m, the sanjakugai (三尺櫂) at about 1.8 m, and the motogai (もと櫂) at about 1.5 m. There is also the heragai (へら櫂), whose tip is flat and spatula-shaped, and which is especially useful for tending kimoto-type shubo (traditional yeast starters). The kaibo plays an important role in the brewing process by promoting yeast activity and making fermentation even. Because the shape and material of the kaibo have a considerable effect on the quality of the sake, the skill of an experienced brewer is required.