Nav barEmail eSakeeSake Site MapJapanese Language eSakeSake Links - Other Web ResourceseSake HomepageStore Help, FAQ, Legal Issues

Sake Brewers Sake Knowledge Sake Store Sake-Food Sake Links About eSake

eSake Logo

Newsletter Archive 2003

Types of Sake
Making Sake
Pub Guide
Sake FAQ
Sake Glossary
Sake Tasting
Serving, Storage
Vital Statistics
Free Newsletter

   Newsletter Archive red check
 Japan Times Archive

Kanji for Sake




Index to All Stories




Top Story

Sake Filtering; Rice Steaming

# 49

Nov. 2003

Sake World Sake e-Newsletter

Issue #49
November 1, 2003

-- Sake Filtering
-- A Steamy Scene
-- Sake Professional Course Announcement
-- Sake Worth Seeking
-- Sake events/Announcements:
-- Subscribe/unsubscribe information
-- Publication information

Sake Filtering
Last month, we looked at nigori-zake, cloudy sake. As mentioned in that article, I try to consistently refer to the step of the process that removes the rice solids (in all sake that is not nigori-zake) as "pressing," rather than "filtering." While in a sense it is "filtering" the lees out, the mash is "pressed" through a mesh. But the real reason I consistently refer to it as pressing is that there is another filtering step used later in the sake-brewing process later.

Soon after having been brewed, most sake is filtered in a curious process in which powdered charcoal is mixed in, and the resulting black liquid is run through a series of filters that look like they are made of coffee filter paper. This is done for a number or reasons, but the most important ones are to filter out unwanted facets of the flavor, and to remove the naturally occurring faint amber color of the sake.

It seems that this charcoal filtering began around 1930. Back then, the level of Ginjo-shu that we enjoy today - taking availability almost for granted -  was what they were submitting to national tasting competitions. Since the judges were showing a tendency to favor sake with lighter coloring, brewers began to strip away some of the natural coloring with these new techniques to appeal to the judges. It soon became the norm. Perhaps because transparent sake exudes more of a "refined" image, consumers too showed more liking for less color. Today, most sake is filtered in this way.

On an interesting tangent, these days the glasses used at the highest level tasting competitions for ginjo-shu are amber colored tumblers. These are used instead of clear glass to actually prevent the tasters from seeing the color, thus preventing them from exhibiting a prejudice for more transparent sake. In the end, color is easily controllable and is not related to the quality of the sake, at least not in such special sake brewed just for contests.

On another interesting tangent, perhaps the leader in this "colorless equals refined" trend was all the Niigata prefecture sake brewers. I was recently at a tasting for one Niigata brewer, and the toji (master brewer) was saying to a well-known retailer that he was not satisfied with his daiginjo as it had a bit of an amber color to it. The retailer laughed and said, "the only ones that worry about that are you Niigata folks. Sake is supposed to have a bit of color!"

In recent years, other methods of filtering have become more common place as well. In place of the charcoal, or sometimes in addition to it, some brewers use mechanical filters with mesh holes as small as one or two micrometers. But the use of powdered charcoal allows for a bit more play and subtle adjustments.

Actually, this charcoal filtering can be incredibly accurate. By varying the size of the charcoal particles, the amount used and the time, brewers can filter for color and to clean up rough spots in the flavor, but they can also filter for either one separately. The technology, so to speak, is actually quite advanced, and most kura are quite adept at using such filtration techniques.

Yet, at times it is overused, and occasionally we find sake over-filtered, and stripped of any character whatsoever. It becomes like "weighted water." When really overdone, it is even possible to taste a semblance of charcoal in the recesses.

However, at the other extreme, this filtering step is not always done. In fact, "muroka," or unfiltered sake (i.e. non-charcoal-filtered), has become popular in Japan over the last few years. A bit too popular, methinks. It seems to be a backlash of the super-refined and very dry sake era of the 80s and 90s, and while backlashes in consumer preferences and normal and desirable, this one often goes a bit too far.

I say this because very often this "muroka" unfiltered sake is also sold as nama (unpasteurized) genshu (undiluted) sake. This combination of being unfiltered, unpasteurized, and undiluted, "muroka nama genshu," while not only being a hassle to remember, also adds up to a huge increase in width, depth, and height of flavor. In other words, this adds up to a huge sake, albeit (to some) appealingly rough-n-ready . While those consumers that clamor for such sake seek stuff close to its most natural state, too often it robs sake of its greatest treasures and quality: subtlety and demureness. But this is a rant for another day.

And, in all fairness, this is not to say that *all* unfiltered sake has such a big, rough- around- the- edges flavor. Not at all. There are some brewers that do not charcoal filter any of their fine sake, never have, and never make a big deal out of it. (Nanbu Bijin sake, produced by Kuji Shuzo in Iwate, is one such example.) A combination of outstanding water, superb skill on the part of the brewers, and massive experience makes such sake wonderfully clean, focused and refined with no filtering whatsoever. There are many brewers that eschew filtering, and still have wonderfully subtle and refined sake - and they don't make a big deal out of it; in fact, they don't even tell you it has not been charcoal filtered..

So, while almost all sake out there has indeed had some charcoal filtering done, some has not. And amongst that sake that is unfiltered, some is fuller and impacting, yet some is elegant and refined. In the end, charcoal filtering is intrinsically neither good nor bad; it is just one more option open to brewers.

There is an interesting historical anecdote tied to the origins of charcoal filtering. It is said that long, long ago in the erstwhile famous brewing town of Itami, a disgruntled brewery worker, fired for ineptitude, sought revenge on the offending toji (master brewer) by secretly dumping a bunch of powdered charcoal into a tank of just-brewed sake on his way out the door. The dismay of the brew crew was soon replaced by surprise, curiosity, and a willingness to experiment when they tasted the result and found it cleaner and more enjoyable than their regular sake. Instead of instilling ire, the discontented lad made a great contribution to the sake brewing world. 

A Steamy Scene: "Cooking" Rice for Sake Brewing
The rice used to make good sake is vastly different from the rice we eat in bowls and under fish as sushi; this point is something that readers of this newsletter have certainly encountered often enough. Yet, even more importantly, the way that sake rice is prepared, or "cooked" as it were, before being used in the brewing process is just as important, and is vastly different from the way normal rice is prepared.

First, let us consider the objectives: one, to get the koji mold to flourish, growing into the rice and creating the array of enzymes needed to chop the starches into fermentable sugars for yeast food, and two, to help the rice to dissolve in an even, predictable way inside the fermenting mash.

Second, why do we need to cook the rice at all? If it has starch in it, is that not enough? Actually, not. "Cooking" the rice softens it, and breaks down the starches to a certain degree (converting beta starches to alpha starches). Without this initial step, the enzymes later can not do their sugar-conversion work. Also, the thorough heat treatment sterilizes the rice, killing any and all bacterial comers that may have been picked up along the way.

But the "cooking" method is somewhat unique. In short, the rice sits in a large cauldron-like vessel called a koshiki while steam is blasted up through it from holes in the bottom for the better part of an hour. Contrast this to the way rice is usually cooked: by mixing it with water, boiling that, and then simmering it until the water is all absorbed. In preparing rice for sake brewing, it never sits in water, but is exposed only to the steam.

In the end, it is all about moisture content. The koji mold needs a very specific water content to propagate properly: just about 38% to 40%. When the rice is soaked in water for a precise period of time and then steamed like this, the water content is perfect. However, if it is prepared by boiling with water first, the water content is about 65%; this is too moist for vigorous koji mold propagation.

Note that rice can also be fried or grilled, i.e. dryly heated, to accomplish the starch breakdown. However, as might be imagined, the water content if far too low for sake brewing.

Also, when rice is properly steamed in the cauldron-like koshiki, it ends up soft on the inside yet firm on the outside; much more so than rice that is eaten. This is good for two reasons: one, the mold has a field day once into the center of the rice grains, and two, the rice dissolves nice and slowly and evenly inside the fermenting tank.

Perhaps the most interesting observation that can be drawn from this discourse is that sake developed as it did over the centuries in a very natural progression. Long ago, people in Japan steamed their rice, they did not boil it. As such, this was naturally how the rice for sake was prepared, and it was miraculously perfect for sake brewing in many ways. So sake is what it is because of the way they cooked the rice in the old days.

When they went back and tried other methods (like boiling or grilling), this one still proved to be the best for sake brewing. It is interesting to note that if people had boiled or grilled their rice long ago, sake today would likely be a completely different animal. The ties to culture are deep.

This is but one example of how sake is closely tied to the history, culture and even anthropology of Japan. In fact, just about any aspect of sake brewing and sake appreciation could be likewise connected to Japan's long past. And certainly this could also be observed for any traditional alcoholic beverage, perhaps anywhere on the planet.

Announcing the Second Annual Sake Professional Course
>From Sunday night, January 11, 2004 to the morning of Saturday, January 17, 2004, I will hold the second annual Sake Professional Course here in Japan. Open to anyone with an interest in sake, this course will provide the environment for a focused, intense, and concerted training period. It will consist of daily classroom sessions on all things sake-related, followed by relevant tasting sessions, and will include several sakagura (sake brewery) visits, and exposure to countless brands and styles in several settings, both in comparison to other sake, and with food.

Participants will stay together at a hotel in Osaka. Lectures will take place inside a sake brewery, and evening meals will be off-site at various sake-related establishments (sake pubs of all shapes, sizes and environments). The optional final night will be spent at "onsen ryokan" (a traditional Japanese inn at a hot spring resort). 

The course is geared toward wine professionals and other industry professionals wishing to expand their horizons in a thorough manner into the world of sake, but anyone is welcome to participate. It will certainly be fun! The course lectures and tastings will begin with the utter basics and will thoroughly progress through and cover everything related to sake. There will be an emphasis on empirical experience, with plenty of exposure to a wide range of sake both in class sessions and with evening meals.

The dates (Sunday night, January 11, 2004  to the morning of Saturday, January 17, 2004) allow participants (from the US at least) to leave on a Saturday and arrive home the following Sunday. (A second weeklong course period is being considered for February.)

The weeklong course, with all instruction, materials, sake, accommodations, and evening meals with sake is JPY350,000 (at 120 yen to the dollar: US $2999). Participation is limited to ten (10) individuals.

For a more detailed description of the course, its content, pricing, and a testimonial reference, please go to

Sake Worth Seeking
Having last month discussed nigori-zake and this month muroka, below are a few relevant recommendations. The sake reviewed here, except where noted, are available in the US. (Apologies to readers not in the US or Japan!)

Tsuki no Katsura Nigori (Kyoto)
This is the brewery that first made nigori-zake legal again in the 60's, and they still make more of it than anyone else in the country, despite their relatively small output. Balanced, smooth and creamy, with an overall sweet flavor profile.

Rihaku Nigori (Shimane)
Tokubetsu Junmai-shu
A rather thin nigori (deliberately so; known as "usu-nigori," a direct translation), but one with a mildly fruity aroma. Too thick a nigori would not allow such an aroma, and this product balances premium sake and the nigori style. Note, this brewery also makes a ginjo version of this product (although that ginjo is available only in Japan) that is even more balanced and aromatic.

Shirakawa-go Sasanigori (Gifu)
Junmai Ginjo
Quite elegant, smooth and creamy, especially considering the pina-colada-like texture. Not as sweet as its appearance would lead one to believe, and mildly fruity with a touch of refinement - for a nigori-zake.

Shinkame Nigori-zake (Saitama)
This one will have its friends and foes, although I am personally quite fond of it. As far as nigori-zake goes, it is a bit thin, and rather than sweet it is decidedly tart and spicy. However, it is also ever so slightly carbonated, not deliberately but rather because it was bottled while very fresh, without fermentation totally halted. Be careful when opening it and drink it soon. (Not available outside of Japan.)

Biwa no Choji Nigori (Shiga)
Another unique nigori-zake: very thick and rich, some of the rice grains are still discernible. It's so chunky, you'll be tempted to eat it with a fork. Mildly tangy yet sweet in the background. Fun and enjoyable. (Not available outside of Japan.)

Sake Events and Announcements
In the US:
Wednesday, November 5, The Japan Society of Boston
Thursday, November 6, Japan America Society of New York
On these two consecutive evenings, there will be a presentation on sake and pottery followed by a tasting of dozens of sake. The evening is co-sponsored by the Sake Export Association, and presentations will be given jointly by myself and Robert Yellin, Japanese pottery specialist, with whom I give regular seminars together in Tokyo. Sake will be poured by the ten or so sake brewers in attendance. For more information and those all-important reservations, contact:

The Japan Society of Boston at 617.451.0726
The Japan Society of New York at 212-715-1229

Most past issues of this newsletter are posted at the below URL:

Questions and comments should be directed to John Gauntner
Copyright 2003 Sake World


Bottom NavbarHomeSake BrewersSake KnowledgeeSake eStoreSake and FoodAbout eSakeSake Workshop