There are two things that make nihonshu unique among the world’s alcoholic beverages. One is the process known as heiko fukuhakko, or multiple parallel fermentation. In short, this means that saccharification and fermentation take place simultaneously in the same vat, as opposed to sequentially, as in other fermented beverages. The other thing making sake unique is the use of koji.
Well, sort of. In fact, other beverages in Asia, most noticeably shokoshu and baichu from China, use a form of this marvelous mold. But the way it is done is a bit different.
As readers may recall, koji is a mold that creates enzymes as it grows. These enzymes break starch molecules down into sugar molecules that can be fermented by yeast cells. Koji also breaks proteins down into flavor-enhancing amino acids.
In Western malt-based beverages, koji is not necessary because enzymes are created when the barley is malted. In Asia, as milled rice is used, no malting is possible and, therefore, the enzymes must come from something else.
In the beverages of China and other Asian countries, rice, barley, chestnuts and other starchy grains are ground into a powder and mixed with water. This is allowed to firm up and then cast into forms varying in shape and size, from little balls to small bricks. It is on this that the koji mold is either deliberately propagated or allowed to occur naturally.
From here, the enzymes produced by the mold convert the starch to sugar, and following that, fermentation and/or distillation takes place. This type of koji is known as mochi-koji, and the methods of creating it have been around for about 2,700 years.
In sake, however, koji mold spores are sprinkled onto rice that has been cooked (steamed) and left to cool and dry just a bit. This is then mixed up every couple of hours, so that at the end of the two-day koji propagation period, each and every one of the grains has the koji mold growing on its surface and into its center. As they have dried out a bit, too, the grains are not stuck together, but exist as discrete little enzyme factories, so to speak. This type of koji is known as barakoji, as the rice grains are bara-bara (all broken up), and this is really what makes nihonshu what it is.
Beyond this propagation technique, the molds themselves are different as well. In Japan, sake is made using a koji mold known to botanists as Aspergillus oryzae. Rhizopus and mucor, which might sound like a couple of alien characters from a sci-fi movie, are the two main molds used in mochi-koji. These two molds are typically found on fruit and bread.
Sake brewing in Japan was influenced in the early days (the Nara Period 710-794) by brewers from China and Korea, most famously by a brewer known as Susukori. Back then, it seems, mochi-koji was in use in Japan as well. Over the next several centuries, however, experimentation led to the bara-koji methods, which were much better suited to the climate of Japan.
These various strains of koji have other differences as well, including the amount and type of enzymes produced, as well as color. The strains used in Chinese mochi-koji are grayish, whereas the barakoji of Japan is a mellow amber when properly propagated. (Shochu uses yet another strain of koji, which is actually black.)
While all beverages made using koji have their own rich heritage and history, they are all extremely different from each other in terms of the final product. Such is the leveraged effect that koji can have — in whatever form it is used.
On Nov. 17, Rob Yellin and I will host another sake and pottery seminar at Mushu. For reservations, e-mail email@example.com or fax (0467) 23-6895.
While Tokyo may not be the bastion of sake-brewing tradition that Kobe, Kyoto and Niigata are, there is still some fine sake being brewed here, a point that is all too often overlooked. Sawanoi, brewed out in Tama, just 60 km from the center of Tokyo, is made with some of the finest water in the country. They are so proud of it that the mineral analysis results are posted for all visitors to see.
This junmai ginjo has a light apple trace to the nose, bolstered gently by a drying acidity. The flavor is light, yet with a solid and slightly grainy feel to the tongue and a clean finish.