However, in the Showa period a pure culture of Aspergillus glaucus (a kind of aspergillus) began to be sprayed on katsuobushi, not only to shorten the period of processing but also to prevent unfavorable fungus from generating, and thereafter this method became mainstream.
しかし、昭和以降は純粋培養したカツオブシカビ（コウジカビの一種）を噴霧することで完成までの日数短縮と、好ましくないカビが発生する問題の回避を行なうのが主流になっている。