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I’ll try not to make this too much of a technical post but we’re gonna delve into brewing techniques a bit. You see there’s more than one way to skin a cat (although I don’t know any) and there’s more than one way to brew sake.
After all the milling, washing and steaming rice preparation is done and it’s time to get down to brewing sake what’s called a moto or yeast starter is made. This is basically a small concentrated nucleus containing koji rice, steamed rice, water and yeast. This is the kick-start to making the sake. More rice, koji and water is added to this moto in larger amounts in three stages till we get to a full batch of sake. In the beginning all moto was called kimoto which was made using a method called yama-oroshi. This involved using wooden poles to mash-up the contents in to a puree like consistency believing this was necessary to get the starch to sugar fermentation process active. This was a very long and tiring process the brewers endured for hundreds of years. Then one day in 1909 a researcher from the National Institute for Brewing Studies discovered that all this puree making business wasn’t actually necessary and if left alone with a bit more water and a slight rise in temperature the koji would dissolve the rice and fermentation would take place.
I would’ve loved to have been at the team meeting when the boss walked in and told the brewery workers that all that laborious yama-oroshi wasn’t actually necessary. I’m sure there would have been some priceless looks on the faces of the brewery team.
Things were sped up even more when it was discovered that adding a bit of lactic acid at the beginning of the moto making process would cut the production time in half. You see, in the kimoto way of making sake this lactic acid came from naturally occurring bacteria that would get in to the mash and wipe out the bad bacteria. Adding the lactic acid at the beginning meant no longer waiting for nature to do its thing.
So that gives us three types of moto making:
Kimoto-the moto is mashed into a paste and naturally occurring lactic acid sanitizes the mash.
Yamahai-this is when they leave the moto to do its thing without turning it into a puree. This method also relies on naturally occurring lactic acid. (the name yamahai comes from yama-oroshi haishi suru which means to discontinue yama-oroshi)
Sokujo-this is the modern method where no mashing of the moto is done and lactic acid is added by the brewer at the beginning to speed things along.
Now it would be fair to wonder why the Yamahai and Kimoto methods are still used when the Sokujo is faster and less labour intensive. Well, it turns out that the Kimoto and Yamahai methods produce a different style of sake. Due to the wild bacteria that are present at the initial start of the moto making process this seems to produce a wilder, some say ‘gamey’ style of sake richer in acidity. Traditionally the yeast used was also wild but these days cultured yeasts are the norm. In the grand scheme of things Yamahai and Kimoto are very much minor styles of sake. Most breweries don’t bother to make them but they are out there and it seems they are quite easy to find in Australia. I believe this to be due to the competition between importers to come up with something unique.
And on that note I present Kaishun’s Kimoto Junmai Ginjo. From Shimane Prefecture this is a great example of kimoto with the added bonus of it being ginjo which is not unheard of but a little unusual for a kimoto. Because yamahai and kimoto are a little wilder they tend to not have the elegance of the ginjo grades, particularly yamahai. Also interesting is this sake has a seimaibuai (rice milling rate )of 50% meaning it could actually be classed as a Dai-ginjo but obviously the brewery has decided as far as they are concerned it sits well as a ginjo. It’s the brewer’s choice. Aromas of peach and melon with a bit rice at the back, finishes long and dry. It would probably work warmed but I didn’t try as it was good enough chilled. It doesn’t really have much of the wild gamey flavours yamahai is more known for but it does have the zippy acidity.
Here is a pretty cool video of the brewers at Uehara Brewery in Niigata making a moto in the kimoto style. Notice the singing. Traditionally this was done to kill time and also as a method of keeping rhythm during the fairly laborious task. Sadly many of these brewing songs are forgotten as they disappear with the old guard.