Every now and then we come across a great page of information about the sake brewing process. This one is from Sake Story and it has a neat little diagram which if you click on parts of it you can see each separate process in detail. Click on the link below to have a look.
It also explains the two fermentation processes, namely the koji stage and then the yeast stage (or moto). Later the mixture is transferred into the tank nad this is called the moromi where it lies for around 30 days (the time period varies depending on what and how you are making your sake).
We hope you will find this delightful resource informing and educational.