Flush water; flushing with water

When moving, filtering, pasteurizing or otherwise transferring sake, some remains in hoses, pumps, filters, jakan heat exchangers and other machines or tools. The same is true for the transfer of yeast starter and moromi. Flushing this clean is called oshi-mizu (押水) or mizu-oshi (水押し) , “pushing with water”. Sometimes the quantity of water is matched to the quantity of remaining sake, or it may be judged by taste at the exit point.

This is done to limit the loss of water, yeast starter or moromi. However, if flushing is carried out too enthusiastically at the end of pasteurizing stage, for example, the alcohol level will be lowered, increasing the risk of hi-ochi , so caution is necessary.

Recently, compressed air is sometimes used instead of water, which method is called ea-oshi (エアー押し) or kuki– (long “u”) oshi (空気押し), flushing with air.   Compared to using water, this has less effect on alcohol level and so on.