Katahaku is a sake (Japanese rice wine) brewing method from the Heian to Edo periods which uses polished white rice only for the kakemai (steamed rice) and unpolished genmai (unpolished rice) for kojimai (malted rice).
It also refers to the sake made by the method.
The name of this method derives from the fact that only one (kata) of the types of rice used for making sake is polished (haku).
It was regarded as being a lower grade sake compared to morohaku which was made using polished white rice for both the kojimai and kakemai. The result was brownish or goldish, and cloudy, with the color of genmai. It is thought to have had a rich taste like modern mirin (sweet cooking sake).
Sake made using unpolished rice for both the kojimai and kakemai was called namizake (regular grade sake).