Goshu-no-nikki (The technical book on sake brewing) (御酒之日記)

Goshu-no-nikki is the first technical book on sake brewing in existence in Japan that was handed down in the Satake clan.

It is one of the records of the time when the Satake clan that would be the lord of Akita Domain later in the Edo period, was Shugo (provincial constable) of Hitachi Province in the Muromachi period, collecting the techniques of sake brewing since the clan was a local ruling family in Satakego of the Province.

There are two theories of 1355 and 1489 regarding the time of completion of the work, but today the latter is accepted more dominantly. Existing copy is a transcription in 1566 owned by Historiographical Institute The University of Tokyo.

This old record is essential to study medieval sake brewed in major temples and the only historical material to know the medieval sake brewing techniques concretely. A variety of recipes are described including superior sake brands of old times such as "Bodaisen" brewed by Bodai-san Shoryaku-ji Temple in Nara as well as "Amano" brewed by Amano-san Kongo-ji Temple in Kawachi Province; and kikuzake (Japanese sake with chrysanthemum blooms) which was used for the Chrysanthemum Festival; and "Nerinuki," a nerizake (antique term for shirozake, or white sake) in Hakata, Chikuzen.

It is interesting to read at the beginning 'Teach orally in confidence' to draw attentions of his successors to keep secrets of the author's techniques.

It shows the high-quality brewing techniques of the time describing a lot of techniques that are used for sake brewing today such as dan-jikomi (the three-stage preparation), morohaku-zukuri (sake made from 100% white rice), pasteurization and lactic acid fermentation.

For example, the topic about pasteurization verifies that the technique was already performed in Japan nearly 500 years before when Louis PASTEUR, founder of bacteriology in the West, 'found' heat sterilization.