I'm Making Shio Koji - I Have Questions About The Process

So I’m fascinated by what I have read about the myriad culinary possibilities at my fingertips using shio koji.

Bought some good rice koji (IseSo Miyako Koji) and have started two similar mixtures of approximately 5:4:1 (water:koji:salt) – for both mixtures I used bottled water and one was warmed slightly prior to mixing. I’m stirring them vigorously each day. House temperature varies between 67°F and 70°F.

Both samples are porridge-ing nicely as described but I’m not quite sure (1) how to evaluate the smell of the transforming product, or (2) how to know when to terminate the transformation by refrigeration.

Most descriptions of the smell have been broad and unhelpful (to me) – everywhere from “sweet and citrus-y and mildly funky” to something like “fruity gym socks”. Most references assure me that I will know if something is wrong – but I don’t feel confident in that since I have no idea how to wholly identify what is right.

My samples are EXTREMELY funky smelling but not offensive (the overwhelming funk is what worries me) – not what I would think of as gym socks (which I associate with some cheeses) – surely there is a clear underlying sweet smell and a distinctive smell of grapefruit rind (at least to me).

If any of you have had rewarding experiences developing shio koji from rice koji, I would appreciate your observations and personal impressions/descriptions of the transformational odors. I embarked on this anticipating a product where the sweet/citrus smell was predominant over the funk but I am experiencing the opposite (and I have no way of knowing if what I have read as a description of funk is the same as what I am smelling in my developing mixtures).

Also, most of the references I have read indicate that I need to develop my shio koji for seven to ten days at room temperature before refrigerating. For any of you who might have significant experience with shio koji, do you have a better way of judging when the process has reached a peak?