Japanese Culture in New York - Chopsticks NY

HOMEFeatureFoodBeautyShopSchoolTravelJapanese Forum
Japanese Culture

The Magic of How “Kobo” and “Koji” Affect Sake

It always amazes me to think that sake is made from only a few ingredients, yet it has such a variety of flavors and aromas.  I knew that the quality of the rice and water that go into it plays a huge role in its taste, but at a recent sake tasting and lecture I was able to learn about how the other two ingredients, yeast (kobo) and rice kernels with mold (koji), affect the sake making process.  This event was held at the Japanese Culinary Center and hosted by Mr. Kosuke Kuji, the fifth generation brewer of Iwate Prefecture based Nanbu Bijin Brewery.  He captivated the audience with his extensive sake knowledge, and I came away with a greater appreciation for this complicated drink.

Creating sake requires three important processes, the first of which is koji making.  This occurs by sprinkling koji-kin, a mold used to break down starch into sugar, on steamed rice that has been cooled and partially dried.  The next step is to add water to the koji and rice and put it in a tank before introducing kobo, which will begin digesting sugars and converting to alcohol.  The final step in the process is for the resulting mixture, or mash, to undergo what is called “double parallel fermentation.”  With this fermentation style, the koji within the mixture converts starch to sugar at the same time the kobo converts sugar to alcohol, a process unique to sake.

With all this talk about technique, we were ready to try the sake that Mr. Kuji had brought from his brewery. The first was a tokubetsu junmai that utilized two types of kobo, both designated as “national kobo” (There are over 3000 kinds of kobo, but only 18 receive this title).  Kuji described the first (#9) as “a country bumpkin with a backbone,” a strong yeast which needs to be balanced out by the second (#18), which is more aromatic and elegant and “NYC style.”  #9 had a banana aroma, whereas #18 was apple or mango, so together they created a fairly fruity sake that kicked off our sampling. The next sake, a daiginjo, was purely #18.  Even though it was made from the same rice as the previous sake, it was more floral in flavor due to the difference in kobo, which really determines the flavor.  The daiginjo was also sweeter than the tokubetsu junmai, and Kuji explained that this is due to its koji-kin: “Sweetness comes from the way in which the enzymes break down the sugar during the sake making process, and this is part of the craftsmanship that the brewmaster employs.”

The third sample was all koji, making it a rich, big-boned sake that packs a punch.  It has a distinctive brown color which can become as dark as soy sauce over time.  Ideally it goes best with meat, whereas the first two are more suited for sushi/sashimi.  Personally I found it a little strong compared to the lightness of the previous two.

The last sake was a true treat, as it was a type that has not yet been released here in the States.  It was a pink ume shu (plum wine) made from junmai sake and plum, to which no sugar had been added.  For me this was the most delicious of the four, and a nice break from the sweetness of typical ume shu which can sometimes be cloying.  Kuji calls this his “miracle ume shu” due to the fact that it is only 7% glucose and low calorie, and says that it is perfect for heavy foods with mayonnaise and meat.

I had never tried such a wide variety of sakes at one time before, and with this experience came a newfound respect for the special techniques involved in making them.  I feel like some of the mysteries of the sake brewing world have been revealed to me, and I will enjoy my next glass of sake even more as a result of knowing what was behind its creation.

1. Mr. Kuji regales the audience with everything they ever wanted to know about sake making.  2. The koji-kin sprinkled on steamed rice. 3. The four sakes sampled were a tokubetsu junmai, a daiginjo, an all koji and an ume shu. 4. The author enjoying the unprecedented sugar-free ume shu.

—— Reported by Stacy Smith

Nanbu Bijin

Japanese Culinary Center