Updated: May 15, 2020
Talking about Japanese sake, we often hear about rice polishing grades. But this sake rice polishing grade, what is it really? To be honest, on a sake label, it is probably the most confusing component, but also a great indicator for it's characteristics.
Sake Polishing Rates Explained
The rice polishing rate in Japanese is called semaibuai (se-ma-i-boo-a-i) and it is probably the most technical and equally confusing for non-Japanese speakers. Why is that, you may ask? Well, let's start with the obvious. For most of us looking at the label of any bottle of alcohol, as son as we see a percentage displayed we assume it is the alcohol content of said beverage. However that is not the case with Japanese sake, as the percentage on a sake label does not reflect the alcohol content, but indicates it's polishing ratio. Meaning how much of the rice remains after the grains outer layer has been shaved off.
I guess this misconception when looking at a sake label, is also the reason why many people refrain from drinking sake. Personally, I did not drink sake for many years, because I assumed it was high percentage and way too strong. I certainly did not want to have the equivalent of a shot of vodka with my dinner. However, once I realised my mistake, I gave it a shot and well the rest is history...
Let’s Start With The Rice
To produce great sake often a special rice variety is being used, which to be honest, is a whole topic by itself and I will go deeper into the subject in the next article. For now what we need to know about is what a rice grain looks like.
Taking a closer look, as with many other grains we find different layers in a corn of rice. With the husk being at it's very outside and as we look further inside, we will find a starchy centre. Now for sake production, we need exactly that starchy part that lies at its core, also called the "Shinpaku", meaning the heart of the grain.
But how do we get to this core? This is why we polish the rice. Because in order to get to it, the rice corns are being carefully polished, to slowly remove the outer layers. And the percentage in relation to this, is what we mean when we talk about the rice polishing rate in Japanese sake. An absolutely vital process in the making of the sake production and a great indicator of what a particular sake will eventually taste like!
Different Polishing Ratios
Polishing rice is a very common process in all rice production, as rice, so we can consume it, is polished to some extent. With brown rice being polished at the lowest percentage. And it is up to each brewery to decide at what rate they would like this ratio to be, depending on the type of sake they intend to make.
For comparison, white table rice is generally polished at about 10%, so this would give it a polishing ratio or semaibuai of 90%. Wait a minute. Why would it not be displayed as 10%? Well, this is another tricky part and highly confusing at the start. Because the semaibuai states what is left, not what has been removed...
As a rule of thumb for Japanese premium sake, a minimum of 30% is removed. As an example, if you read 40% on a label, that means 60% of the outer layer of the rice has been removed, leaving us with 40% to be used for the sake production. That means, basically less than half of the rice corn is used. That is a lot of waste right? Yes it is, but again, as we are trying to get to the starchy part of the rice corns, the more that is removed, the finer the sake will become.
Why Does Rice Polishing Matter?
Well, it does and it doesn’t. However, it affects the taste of the end product significantly. Putting it quite simply, removing more of the outer layers of the rice corn often creates a sake with a more refined taste (with some exceptions).
I keep thinking about eating a potato. Peeling it, it will make it taste smooth, but leaving the skin on, will give it a tougher taste, more earthy and rough.
The same happens when you polish rice to make sake. Not removing a high amount of the outer layer will not make the sake worse, it will just make the taste different. And so it is often not a question of the more the better, but eventually comes down to taste, which will always be a very personal matter.
What Does The Rice Polishing Rate Tell Us?
I think one of the most useful things about it, is that you can tell it’s classification and therefor get an Idea of what a particular sake will taste like. So even if you are not able to read Japanese, from the polishing rate you can tell if it’s a “DaiGinjo” (50% or less Polishing), “Ginjo” (60% or less Polishing), or “Futsu” (70% or less Polishing). Which are some of the official sake classifications.
Also, although not highly scientific. It is a way that helps you choose and find a sake you may enjoy. For example, if you like a sake that is easy to drink with somewhat finer aromas, it is quite likely that a sake with polishing rate of 50% or lower, will be to your liking.
So this was an overview what the rice polishing grade tells us and how it can help when choosing a sake.
Although, as you will also find out or already know, there is of course so much more to the taste than just the semaibuai. With aromas and flavours varying so much, not just from region to region, but of course also from styles and brewing methods. It is a joy to discover them all, but more about this next time...
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