Is aeration really necessary?

Hello NB community,

I am currently finishing writing up on a project I did on brewing of sake at university and I accidentially stumbled on a sake article written by some Japanese guys. Now for half a year me and my friends have been vigourously shaking some 30 liters fermenters in order to mix and aerate the mash. But in this article and several others they make a completely anaerobic primary fermentation (without presence of oxygen). Sake yeast require oxygen for production of sterols, which are the components of a healhy cell wall. However in sake brewing, these sterols are provided by Koji and as a result makes it so that yeast cells do not need any added oxygen…

So you may want to reconsider that excessive amount of aeration especially during the primary…

Source: … 097-06.pdf

(Search for ergosterol)

Just a quick question, does aeration hurt the process for the first week of fermentation? I don’t aerate the whole time.

I will need a little clarification on that question :slight_smile: when you say the first week of fermentation do you mean (moto, build up, primary fermentation?)