Is the  “Nihonshu-do” or “sake degree” a useful reference?

First of all, I am not a critic. Please read this article with that understanding. My answer is “it’s better than nothing.” 

In a previous article “Dry sake has been booming in Japan”, I explained that the Sake degree is just the specific gravity of the sake relative to the water. So how many indicators are there for the taste of sake? Sweetness, sourness, astringency, bitterness, umami, aroma, alcohol concentration, etc. Furthermore, there is not just one type of each. And the balance of each changes depending on various factors such as the time it is in contact with oxygen in the air, the temperature of the sake, the air temperature, the humidity, the material of the glass, and the shape of the glass. With all these factors intertwined, it is very doubtful how much meaning an indicator of specific gravity alone has.

So I say again. It’s better than nothing. So you have no choice but to check it out with your own tongue. 

Conveniently, restaurants and izakayas that focus on sake have something called a “sake tasting set.” They serve small amounts of several types of sake. One thing to note in this case is that there may be a set that combines the same brand of junmai, ginjo, and daiginjo. This can be educational in itself, but if possible, choose a set that combines different types of sake. Some places will let you choose the sake to pair with them. In that case, it’s a good idea to ask the store manager for consultation. You may make some unexpected discoveries.