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Koji - All You Wanted to Know (Part 1)

# 10

June 2000

Sake World Sake e-Newsletter

Issue #10
June 23, 2000



-All you ever wanted to know about koji , PartI
-Of Rice and Region, Part I
-Sake to look for
-Sake-related events
- Subscribe/unsubscribe information
-Publication information


The sake brewing process is still quite etheric to most of us, being unlike any other brewing process we might be familiar with. It' not something most people have seen, and is a bit of a big "lack box"for the majority of sake fans. That' fine, really. No one says you need to know how something is made to enjoy it.
But should you have an interest, when you begin to read up on the topic, you soon hear about this mystery stuff called koji. The creation of sterling koji is indeed the heart of the sake brewing process. But just what is it, and why is it so important?
Koji works to break down starch molecules into sugar molecules which can then be processed by yeast cells, which is what fermentation is all about.
In winemaking, there is sugar already present in the juice of the grapes, and the yeast can then be added to that. For beer and other malt-based beverages, malted barley contains enzymes that are activated when soaked in hot water at very specific temperatures. These enzymes break down the starch in the barley into sugar to be used as food for the yeast. After this step, yeast is added, and fermentation begins.
In sake brewing, there is no way to malt since the husks have been milled away, and only white rice remains. This means that enzymes cannot be extracted from the rice itself. Still, these enzymes must be supplied from somewhere, or the starch will remain starch, and there will be no sugar for the yeast to use as food, turning it into alcohol and carbon dioxide.
Enter the mighty mold Aspergillus Oryzae, the scientific name for koji spores. Although koji spores are found floating freely in the air, for sake brewing they are cultivated and sold by one of a half-dozen companies that specialize in that.
he dark greenish-yellow, extremely fine powder is sprinkled lightly over freshly steamed rice and coaxed into propagating on and into the rice grains. The process takes 42 to 50 hours or so, and is done in a special room, warmer and more humid than usual.
As it does so, the highly sought enzymes are created and activated, turning starch into sugar along the way. When finished, koji looks like rice with a bit of white frosting on it, and smells a bit like chestnuts. This finished koji is used in the brewing process four times, being mixed with water and plain steamed rice in the fermenting mash.
Simplifying the koji-making process, about which reams of research and eons of experience have been accumulated, into the above few paragraphs borders on insulting. As if to make up for this, we will look at the koji-making process in a bit more detail in later issues of this newsletter.
Should you ever get dragged into a conversation on this topic, keep in mind that the word koji itself refers to the finished product; i.e. the rice with the koji mold grown onto it. The koji mold itself (i.e. the spores, in the form of the greenish powder) is referred to as tane-koji, or koji-kin. It is often nicknamed moyashi by those in the industry.
Tane-koji was first brought over in its isolated form from China in about 200 A.D., and eventually harnessed and studied and manufactured. The word itself is a shortened form of the word kabitachi, meaning "loom of mold."There are about four billion spores in a single gram of tane-koji, and it takes about 100 grams to make a large tank of sake.
There are several thousand strains of tane-koji. Various strains are used in the production of shoyu and miso as well as sake, shochu and awamori. It is also used in production of the Chinese beverage lao-chu, although the methodology is somewhat different from that of sake brewing.
Koji is produced by only about a half-dozen companies in Japan. This is surprising in light of the fact that annual production of shoyu, miso and sake combine to exceed one trillion yen, and make up almost two percent of the gross national product of Japan.
These various strains of tane-koji differ in their capacity to produce various enzymes, specifically proteolytic, lipolytic and amylolytic enzymes, for those that simply must know. Each enzyme performs a different chemical activity, and different types of sugars are produced by each as well. Naturally, shoyu, miso and other products all call for different types of enzyme activity.
The tane-koji is prepared at the koji-mold factory by inoculating the spores onto brown rice, treated with wood ash which acts as a preservative and source of mineral nutrition. This is how the sake brewers receive it; it looks like exactly what it is ?moldy rice. As the tane-koji is shook inside a screen-bottomed can or small cloth bag, the spores come delicately dancing out and lay to rest upon the rice. From there the mold begins to grow.
Even within those tane-koji strains used for sake brewing, there are subtle differences. Several types are mixed in exacting proportions, not unlike a recipe, to create a blend for very specific needs. A catalog from Akita Konno, one of the handful of tane-koji producers, lists about a dozen selections for sake brewing. All have proprietary names, and a description of their special characteristics.
For example, one may be specifically for making fragrant sake, another for ginjo-shu in general, yet another may help create sake with a higher than average acidity. The chemical characteristics of each, including the relative strength of the various enzymes, are listed in chart form for perusal and comparison.
There is not, it seems, a lot of experimentation with tane-koji in the sake-brewing industry, in the way that there is with rice and yeast. Most brewers stick with one producer and specific tane-koji for a specific job, preferring it to be one of the few constants of the brewing process. With so much affecting the quality of the final koji while making it, one more variable is not needed.
Perhaps the reason that more information about koji is not available on labels and such is that its use is so deep in the recesses of the process. Perhaps it is simply because most laymen would not likely be interested. In the end, the flavor of a sake and our preferences are all that matters, but the moldy world of tane-koji at least deserves a look.
Of Rice and Region
Japan is not a large country. The entire land mass would fit inside the state of California. Yet, the diversity of culture, language and cuisine from one end to the other is astounding. Naturally, just as wine is closely associated with region, sake from throughout Japan has styles that developed in the various regions that are distinct and representative.
These distinctions are not nearly as clearly delineated as they once were. As recently as a few decades ago, before the transportation infrastructure became the well-oiled machine that it is now, the various regions were a bit more isolated from each other than they are now. Recently sake styles throughout the nation have become a bit homogenized.
Yet enough differences remain to warrant discussion and study. There are a number of factors that contributed to the development of these differences in style. Some of these are similar to conditions in the world of wine and fairly obvious. Others are less obvious and unique to Japan.
One reason is, of course, rice. Rice varietals tend to grow well in some regions and climates but not well in others. Originally, sake breweries tended to use rice grown locally whenever they could, and this led to the creation of different flavors and nuances. Note however that this is no longer a major factor in determining regional distinction. Why? Because in Japan, rice can be shipped from any region to any other region. Some of the best sake rice grows in the western part of Japan, for example. This is routinely shipped all over the country to kura (brewery) for brewing (although it still constitutes a very small amount of the total rice used in brewing; not much of this top-grade rice is grown). There is no limitation on keeping rice in the region it was grown.
Technology has also allowed many new varietals of rice to be developed, so that kura are no longer limited to what they once were, in terms of rice.
A second factor contributing to sake styles is water. Today water can to a certain degree be doctored to produce precisely what is wanted, but long ago kura were often set up in a particular place precisely because of the quality of the water. (The largest brewing region in Japan, the Nada ward in Kobe, exists because of the famous water found there.) But there are definite limitations to this filtering and chemical adjusting of water. If a kura does not begin with decent water, all the technology in the world will not help to brew good sake.
Most water used for sake brewing in Japan is either well water, often from deep wells, or water that runs down from the mountains, filtered ever so slowly by layers and layers of ancient rock. But environmental changes sometimes require that water like this, once pure, now be filtered or altered chemically.
Styles and flavor profiles developed based on the local water. Although overall Japan has slightly soft water (on the pH scale) in most places, hard water, soft water and everything in between can be found, with various mineral and chemical components affecting flavor and impact, viscosity and mouth feel. Water, in fact, may have more of a profound affect on the final product than any other factor.
Sake flavor profiles were further affected by local cuisine. Japan has a fairly diverse landscape, with warm regions, very cold regions, several long mountain ranges, and of course plenty of seacoast. People living near the coasts and in large populous plains had access to much fresh fish and other lighter-flavored food. Those living in mountainous regions or areas isolated by mountain ranges had to rely more on preserved foods, often fermented, with perhaps stronger flavors (Japanese mountain food is wonderful cuisine, by the way). Naturally, locally brewed sake would be made to go well with the food, and sake going with light food would be different from that going with stronger flavors.
Yet another factor is the culture that grew surrounding sake brewing in which the actual people doing the brewing were rarely if ever (indeed, even today there are few examples to the contrary) the owners of the kura. They were seasonal workers, farmers from the countryside with nothing to do in the winter.
The head brewer of each brewing team, known as a toji, often resided near other toji when home in the summer, as most of these seasonal workers came from the same towns. They generally formed groups like labor unions, and would exchange techniques and notes, creating styles of brewing based on certain methodologies. Different toji groups performed the various steps in different ways, which led to identifiable differences in their respective sake. This has long contributed a great deal to regional styles, and often the ryuha, or regional group from which a toji has come, is listed on the back label of a bottle of sake.
All of the above circumstances and conditions came together to create flavor profiles and sake styles distinct to each region. These have been around for centuries, but over the last few decades the distinction between the various regions has begun to blend and become fuzzy. Styles are to some degree homogenizing.
This can be attributed in part to the distribution system and infrastructure. That same wonderful technology that allows one to get sake from anywhere with relative ease also transforms the local market of any kura into a national market. Competition comes streaming in, as does marketing information and public opinion. The preferences and tastes of the masses change. Whether they like it or not, brewers need to make sake that is popular.
But enough regional distinction remains to keep things interesting and make it worth noting where a sake is from. In fact, in Japan anyway, it is very rare indeed to hear or read the name of a sake without the name of the prefecture parenthetically trailing close behind.
Over the next few issues of this newsletter, we will look at the most well-known, famous, and important sake brewing regions, their various characteristics, and representative sake from each region.
Sake to Look For
Wakatsuru "oushin" Junmai Daiginjo (Toyama Prefecture):
Soushin is a nice, classy daiginjo with a bit of melon and apple lacing the nose, and a crisp, dry flavor overall. It has recently become available in the US, at least in New York.
Founded in 1861, Wakatsuru means "oung Crane."Wakatsuru has two breweries close to each other, and each has a toji (head brewer) from a different regional "chool." As this kind of thing goes quite far in determining the style of the sake, it is somewhat rare to have a situation like this. 

Hiroki (Fukushima Prefecture):
Hiroki has recently surged in popularity. They have several products that are worth tasting, including a muroka (unfiltered) nama (unpasteurized) genshu (undiluted sake). In fact, most of their products readily available seem to be muroka and nama. Slightly dry but thick and crisp, with a light fragrance and excellent balance all around. Fairly representative of sake from Fukushima.
The current president, the 9th generation, is also the toji. This is as amazing as it is rare, and came about when the former toji (head brewer) passed away in 1996. Chances are he has not much free time. They almost threw in the towel, but decided to continue, encouraged by several sake specialty shops. Their sake has become much more popular since. Hard to find as it doesn' stay on the shelves long, Hiroki is only available in Japan.

Juyondai, Yamagata Prefecture
Looking back over the year or so of these newsletters, it is hard for me to believe that I have not yet written up Juyondai. It suffers from so much media attention and hype that it has become annoying. Juyondai this and Juyondai that, heaps of praise on the young brewer who is also the successor of the helm, accolades and praise above and beyond the call of media hype.
And, after all that, I must admit: their sake is excellent; one of my personal favorites. Almost anything they make is delicious and moderately priced. When fame came along, unlike many other breweries, they refused to do two things: raise their prices or increase their production. As such, it can be hard to get. It is not available in the US except in an aged form which will not impart the awe-inspiring impression of its younger cousins.
Generally elegant and fragrant, balanced and layered and lively, but never cloying or obnoxious. Most Juyondai is fruitily fragrant to some degree. Various rice strains are used in their different products, each imparting a noticeable character.

Umenishiki, Ehime Prefecture
Umenishiki has long been famous, and has slowly grown over the years to be of formidable size in the brewing industry. They make a wide range of sake styles and products that have an appropriately wide range of flavor profiles. They seem to be able to brew with great precision almost any kind of sake.
Most of their sake is fairly full flavored, crisp, and with a higher than average acid presence the flavor. Some of their sake, however, is very soft and absorbing, melting fast into the palate and disappearing. A group of wives of sake retail shop owners gathers each year at the brewery to help brew a tank or two of sake that will bear their names; this sake is of that soft type. There are several Umenishiki sake (but not the wives'brew) available in the US.

 Kotsutsumi, "enraku"Junmaishu, Hyogo Prefecture

The name Kotsutsumi refers to a small drum used in a form of traditional Japanese dancing. The grandfather of the current president was a haiku poetry student of a famous haiku poet, and the name Kotsutsumi was given by that famous poet. The labels are all created in a funky, hard-lined and colorful style that make products from this sake brewery immediate recognizable.
Somewhat different from the typical sake from this region. A very unobtrusive and subtle flavor, wonderfully intuitive. You don' realize how good it is until about two seconds after you taste it. It also presents fairly different faces at chilled, room temperature, and warmed manifestations. Available in a limited basis in the US.

Sake-related events
Japan Times Ceramics Scene writer and Japanese pottery expert Robert Yellin and I will be doing a joint seminar on sake and pottery in either late August or early September, at the sake pub Mushu in Awajicho, near Shin Ochanomizu/Awajicho Stations, from 6pm to 9pm. The evening will include a meal, half a dozen or so good sake, and lectures by Rob and I. Seating is limited and fills up fast.
To make a reservation, silly though it may seem since the date has not yet been firmly set, email me or fax me.
Famed sake critic Haruo Matsuzaki will be holding a sake seminar on Saturday, June 24, from 6:30 until the last train at Romantei in Akebono-bashi (Yotsuya Yanagicho). Although this seminar will be entirely in Japanese, Matsuzaki-san' level of knowledge and experience are incredible. Seminars feature a short lecture with tasting, and an optional but highly recommendable konshinkai (party) with food afterwards downstairs. Although there is not much time before this Saturday, those interested can make a reservation through me at The next such event, by the way, will be Saturday July 22.
On Sunday, July 23, Matsuzaki-san will then lead a tour up to Tochigi Prefecture, to a sake brewer called Shimazaki Shuzo, brewers of Azuma Rikishi, in a small town called Karasu-yama. The trip will take about two hours from Tokyo. Although no brewing is presently going on at the brewery, the town is old and picturesque, and there also happens to be a festival taking place that weekend for which Karasu-yama is famous. Although the festival may be interesting, the owners of Shimazaki Shuzo are very warm and congenial, and wonderfully generous to visitors. (Read: copious amounts of fine sake for free tasting.) If interested, contact me and I will be happy to put you in contact with the right people.
Also, those interested in attending any of Haruo Matsuzaki' seminars can now check out the topics and schedules for themselves at
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Sake World is distributed free via email only with the intent of disseminating useful information about sake and the culture and world that surrounds it. Information on sake, sake production, sake shops and sake pubs, sake events and sake culture are included, targeting audiences both in and out of Japan.
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Copyright 2000 Sake World




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