Sake is a Japanese product of fermented rice through a special yeast ‘koji kin”, with an alcohol strength of between 14° and 20° after filtering or not, that is then either pasteurized once, twice or not at all. It lies within the family of “Nihonshu” meaning Japanese alcohol which can be, non-filtered like Nigori or pasteurized like a Jun mai, slightly aged or even distilled, but then it would be “Shochu”.
The best approach would be to think that in France we have wines filtered, non-filtered and oxidized, fortified wines and distilled wines.
My principal experience has been with Masuda San, 14th generation of the Tsukino Katsura “Kura” (Brewery) established in 1675!! We are near Kyoto.
Different rice strains can be used, there are as many as 50 but the names that pop up the most are Yamada Nishiki, Mayami Nishiki and Omachi. I believe that Masuda san uses Yamada Nishiki grown not too far away from the Kura. There are many regions for nihonshu, Kobi, Niigata, Ishikawa, Kochi to name but a few.


“Seimaï” Rice polishing
The quality of the nihonshu is directly proportional to how much of the outer case is polished off. The more that is taken off, the closer to the very heart of the rice grain where the highest concentration of starch lies. This remains a delicate operation, cracked grains are not good and if too much heat is created during the polishing then the grain will not absorb as much water when being soaked in the next paragraph. The powder remaining after the rice has been polished is called “nuka” and is used in biscuits, and low quality alcohol products. The percentage left is called “seimaibuai”.

The rice is then washed to remove the powder coating, the nuka. The rice is then soaked in tubs as a pre preparation for the steaming. The timing appears to be crucial and there is someone from the kura brewery team,”kurabito” counting the time that the rice stays in the water.

Now the very small grains of rice are put into a steaming tun called a “koshiki” and rice is pumped up from the bottom into the rice. This will soften the rice up and ready it, once it has cooled down to go into the koji room “koji muro”. Here I was dressed up as if I was in an operating room. Cloak, hair cover, covers over my shoes; if the seimai was a delicate operation this is even more fragile. It’s quite warm inside the koji room with a higher humidity.


Saccarification.
The rice is laid in small wooden trays with a cloth around each batch and green koji spores (Aspergillus oryzae) are sprinkled onto each batch or tray. The rice will be mixed and taken care of for a couple of days. The rice mixed with the koji kin is developing enzymes that will break down the starch, but this in turn creates extra heat which must be evenly distributed in the kura muro, turning the rice every two hours, even at night time, the kurabito relaying.

After two days the rice looks as if it has been frosted with a slight woody/walnut smell


“Moto”
To start the fermentation process a concentration of rice, koji and extra concentrated yeast is used. This is called the “Moto’. A two week operation that will add steamed rice and koji into a turbo powered fermentation starter.

Then the moto is transferred into a sort of ‘wash back’. The wash is called “moromi”
Four days of developing the mash (moromi) 1st day, an addition of rice, koji and water, second day, the moromi is left alone “odori’, the third day, the double of what was put in before of rice, koji and water is added and on the fourth, the double of the third. This is “sandan shikomi”, San being ‘three’ evoking the three steps. The fermentation can take the alcohol level naturally to 18 -20°abv which is very high. A vin doux naturel does have a residual strength of 21.5°, but, 5 to 10% of very pure alcohol would have been added during its fermentation. In the sake, nothing has been added.

1 month later, or less, it’s time to put the mash into bags and let the liquid run off


Filtering
Pasteurization; the nihonshu is pasteurized if it’s not meant to become “Nigori”, a slightly milky, with a faint natural effervescence. But in order to keep this not pasteurized nihonshu stable, it must stay in the fridge. The name for un pasteurized sake is “nama –saké”. But sake can be thus or pasteurized once or pasteurized twice depending on a personal descision. The usual method passes the sake through a serpentine which itself is steeped in HOT water, just the opposite of what happens in alcohol distillation.



Types of Saké or Nihonshu
Nigorizaké means cloudy wine. This is the non-filtered saké that resembles the historical beginnings of saké brewing. It’s slightly fizzy with a sweet and dry flavor accompanied with a light texture resembling that of a macha tea. The opening of the bottle is quite a ritual in itself and should be done slowly in order to let the gas rise and mix perfectly at the same time the wine.

A ordinary saké called Futsūshu that seems to be the most popular but it is also of the least quality. There are not many rules attached to its polishing or really how it is made at all. It can even be watered down before bottleing.

Tokutei-meishoshu. This is the base of the good saké level with controls on the polishing and added or not alcohol. It’s the everyday saké.

Honjozo-shu. The rice has had 30 % of its original volume polished off. The term used is “seimai-buai 70%. Alcohol will be added before the wine is filtered. This is a very popular sake although some purists do not like the idea of adding alcohol.

Junmai-shu. This is really agreable to me, pure and perfumed with absolutely no alcohol added. However, due to the different levels or depths of rice polishing “seimai-buai” it opens a sub sub category!

Tokubetsu-junmai-shu is an especially pure saké
Junmai-ginjōshu 30 to 40% of the rice has been polished down giving a seimai-buai of 70 to 60%.

Ginjō-shu 40% polished off so seimai-buai of 60% with a slow fermentation at a low temperature.

Daiginjō-shu. This one has the rice that is really, really polished down so I’ll say directly a seimai-buai of 35 to 40%. So it’s expensive. Oh! And it has alcohol added!

Junmai-daiginjō-shu. My favorite, the same rice polishing as the above, possessing a seimai-buai of 40 to 35% but remaining beautifully pure. A bouquet that is lovely reminding me of the koji and sakura, the cherry blossoms, at the same.