Sake

General Info – all information from sakeworld.com

Five crucial elements are involved in brewing sake -- water, rice, technical skill, yeast, and land / weather. More than anything else, sake is a result of a brewing process that uses rice and lots of water. In fact, water comprises as much as 80% of the final product, so fine water and fine rice are natural prerequisites if one hopes to brew great sake. But beyond that, the technical skill needed to pull this all off lies with the toji (head brewers), the type of yeast they use, and the limitations entailed by local land and weather conditions. Please visit the links shown above for a detailed review of the crucial ingredients.Rice is washed and steam-cooked. This is then mixed with yeast and koji (rice cultivated with a mold known technically as aspergillus oryzae). The whole mix is then allowed to ferment, with more rice, koji, and water added in three batches over four  days. This fermentation, which occurs in a large tank, is called shikomi. The quality of the rice, the degree to which the koji mold has propagated, temperature variations, and other factors are different for each shikomi.This mash is allowed to sit from 18 to 32 days, after which it is pressed, filtered and blended.

 

Steps of Production

Rice Milling

After proper sake rice (in the case  of premium sake, anyway) has been secured, it is milled, or polished, to prepare it for brewing good sake. This is not as simple as it might sound, since it must be done gently so as to not generate too much  heat (which adversely affects water absorption) or not crack the rice kernels (which is not good for the fermentation process). In the photo on left, the rice in top left corner is  unmilled, the rice next to it has only 70% of kernel remaining, while the rice at bottom has been milled  so only 35% remains. The photo at top right (with red  background) shows rice ground to 50%. The amount of milling greatly influences the taste.

Washing and Soaking

Next, the white powder (called nuka) left on the rice after polishing is washed away, as this makes a  significant difference in the final quality of the steamed rice. (It also affects the flavor of table rice; try washing your rice very thoroughly and notice the difference in consistency and flavor.) Following that, it is  soaked to attain a certain water content deemed optimum for steaming that particular rice. The degree to which the rice has been milled in the previous step determines what its pre-steaming water content  should be. The more a rice has been polished, the faster it  absorbs water and the shorter the soaking time. Often it is done for as little as a stopwatch-measured minute, sometimes it is done overnight.

Steaming

Next the rice is steamed. Note this is different from the way table rice is prepared. It is not mixed with water and brought to a boil; rather, steam is brought up through the bottom of the steaming vat (traditionally called a koshiki) to work its way through the rice. This gives a firmer consistency and slightly harder outside surface and softer center. Generally, a batch of steamed rice is divided up, with some going to have koji mold sprinkled  over it, and some going directly to the fermentation vat. (Photo at left: rice steaming in koshiki, or vat). 

Making Koji (Seigiku)

This is the heart of the entire brewing process, really, and could have several chapters, if not books, written about it. Summarizing, koji mold in the form of a dark, fine powder is sprinkled on steamed rice that has been cooled. It is then taken to a special room within which a higher than average humidity and temperature are maintained. Over the next 36 to 45 hours, the developing koji is checked, mixed and re-arranged constantly. The final product  looks like rice grains with a slight frosting on them, and smells faintly of sweet  chestnuts. Koji is used at least four times throughout the process, and is always made fresh and used immediately. Therefore, any one batch goes   through the "heart of the process" at least four times.

Making Yeast Starter

A yeast starter, or seed mash of sorts, is first created. This is done by mixing finished koji and  plain steamed white rice from  the above two steps, water and a concentration of pure yeast cells. Over the next two weeks, (typically) a concentration of yeast cells that can reach 100 million cells in one teaspoon is developed.

The Mash (Moromi)

After being moved to a larger tank, more rice, more koji and more water are added in three successive stages over four days, roughly doubling the size of the batch  each time. This is the main mash, and as it ferments over  the next 18 to 32 days, its temperature and other factors are measured and adjusted to create precisely the flavor profile being sought. 

Pressing (Joso)

When everything is just right (no easy decision!), the sake is pressed. Through  one of several methods, the white lees (called kasu) and unfermented solids are pressed away, and the clear sake runs off. This is most often done by  machine, although the older methods involving  putting the moromi in canvas  bags and squeezing the fresh sake out, or letting the sake drip out of the bags, are still used. (Photo at right: bags of moromi from which sake is being drip-pressed. Below Photo: a fune, used  for pressing sake out of bags of moromi).

Filtration (Roka)

After sitting for a few days to let more solids  settle out, the sake is usually charcoal filtered to adjust flavor and color. This is done to different degrees  at different breweries, and is goes a long way in dictating the style.

Pasteurization

Most sake is then pasteurized once. This is done by heating it quickly by passing it through a pipe immersed in hot water. This process kills off bacteria and deactivates enzymes that would likely adverse flavor and color later on. Sake that is not pasteurized is called namazake, and maintains a certain freshness of flavor, although it must be kept refrigerated to protect it. 

Aging

Finally, most sake is left to age about six months, rounding out the flavor, before shipping. Before shipping it is mixed with a bit of pure water to bring the near 20 percent alcohol down to 16 percent or so,  and blended to ensure consistency. Also, it is usually pasteurized a second time at this stage. It is somewhat unfair to the sake-brewing craft and industry to reduce sake brewing down to the short explanation above, but excessive detail would soon go beyond the scope of this book. The basics are as explained here.

 

Types of Sake

Junmai-shu                  

This can be translated as pure rice sake. Nothing is used in its production except rice, water, and koji, the magical mold that converts the starch in the rice into fermentable and non-fermentable sugars. Junmai-shu is made with rice that has been polished  (milled) so that at least 30% of the outer portion of each rice grain has been ground away. The taste of junmai-shu is usually a bit heavier and fuller than other types, and the acidity is often a touch higher as well.

Honjozo-shu        

Honjozo is sake to which a very small amount of distilled ethyl alcohol (called brewers alcohol) has been added to the fermenting sake at the final stages of production. (Water is added later, so that the overall alcohol content does not change.) Honjozo, like  Junmai-shu, is made with rice that has been polished (milled) so that at least 30% of the outer portion of each rice grain has been ground away. This, plus the addition of distilled alcohol, makes the sake lighter, sometimes a bit drier, and in the opinion of many, easier to drink. It also makes the fragrance of the sake more prominent. Honjozo often makes a good candidate for warm sake.

Ginjo-shu         

This is sake made with rice that has been polished (milled) so that no more than 60% of its original size remains. In other words, at least the outer 40% has been ground away. This removes things like fats and proteins and other things that impede fermentation and cause off-flavors. But that is only the beginning: ginjo-shu is made in a very labor intensive way, fermented  at colder temperatures for a longer period of time. The flavor is more complex and delicate, and both the flavor and the fragrance are often (but not always) fruity and flowery.

Daiginjo-shu        

Daiginjo-shu is ginjo-shu made with rice polished even more, so that no more than 50% of the original size of the grain remains.  Some daiginjo is made with rice polished to as far as 35%, so that 65% is ground away before brewing. Daiginjo is made in even more painstaking ways, with even more labor intensive steps.

Nama-zake        

A term for any unpasteurized Sake

 

Junmai Ginjo

This is sake made with rice that has been polished (milled) so that no more than 60% of its original size remains. In other words, at least the outer 40% has been ground away. No alcohol added.

 

Junmai Daiginjo            

Daiginjo-shu is ginjo-shu made with rice polished even more, so that no  more than 50% of the original size of the grain remains. No alcohol added.

 

Nigori-zake

Nigori-zake is cloudy sake, sake that has not been pressed fully from the fermenting rice solids. Most people have seen it:  the white, cloudy, usually opaque sake sometimes seen in shops and restaurants. That is nigori-zake, which simply means "cloudy sake."The "clouds"are nothing more than unfermented rice solids deliberately left floating around inside. There are several styles or forms that nigori-zake can take. Much nigori-zake is sweet and smooth and creamy in texture. Then there is the "o chunky you'll want to eat it with a fork"variety of nigori-zake. Naturally, nigori-zake does not offer the subtlety and refinement of good premium sake. Although it can indeed be tasty and fun, the remaining lees and their flavor easily overpower any other fragrances or gentle nuances of flavor. Also, nigori-zake should always be served a bit chilled.

 

Yamahai-shikomi

From hundreds of years ago until the early 1900's, it was thought that the rice and koji had to be mixed and crushed into a puree when creating the moto in order for them to work properly together and convert the starches to sugars. To achieve this, kurabito (brewery workers) would ram oar-like poles into the small vat for hours on end to make a smooth paste of the contents; exhausting work to say the least. This pole-ramming activity is known as yama-oroshi. This yama-oroshi pole ramming is one of the most classic sake-brewing scenes around , and is commonly seen in paintings, and on old films at sake museums such as those at the larger breweries in Nada. It is during such activities that kurabito of old would sing traditional brewing songs, all but forgotten now, to keep them awake and active, and to help them count strokes. Then, in 1909, Mr. Kinichiro Kagi at the National Institute for Brewing Studies discovered that all that hard work simply wasn't necessary. If left alone, the enzymes in the koji would eventually dissolve all the rice in the developing moto anyway. No tiring pole -ramming was needed. The only catch was that you had to add a bit more water, and keep the temperature a bit warmer, a comparatively painless process. *Now you tell us!* rose the silent cry from countless exhausted brewery workers, past and present. When it became known then that the rough part (yama-oroshi) could be ceased (hai-shi),  yama-oroshi hai-shi, shortened to simply yamahai, was born. But technology wasn't finished poking fun at tradition. Ah, no, there was more mockery in store. In 1911 it was discovered that by adding a bit of lactic acid to the moto at the beginning, the whole thing could be accomplished in about half the time. Lactic acid is a product of the yeast life cycle, and when present in sufficient amounts, it prevents wild yeast and unwanted bacteria from proliferating and adversely affecting the flavor. When the yamahai process is used, since the lactic acid comes into existence more slowly, a bit of funky bacteria and even wild yeast cells inevitably make it into the moto as it develops. This gives rise to gamier, more unabashed flavor profile in the end. Yamahai moto takes about a month to develop, and can be nerve wracking as those stray bacteria and wild yeast cells can ruin a whole batch if they are not kept in check to some degree. Sanitation is paramount, and pains must be taken to keep the developing moto covered and protected. Adding lactic acid at the beginning speeds the process up, allowing the moto to be ready for use in about two weeks. It also protects it from the start, putting everyone at ease. This alter-ego of yamahai, in which a bit of lactic acid is added in the beginning, is known as sokujo moto, or *fast-developing* moto. Due to a characteristic resistance to new -fangled technology, it took about ten years for sokujo-moto to gain acceptance on an industry-wide basis. However, most sake today is created using sokujo moto method, as it is faster and easier and leads to a cleaner flavor. In a sense, yamahai is for those with more eclectic tastes.

 

Kimoto

Beyond the standard method (sokujo moto) and the yamahai-shikomi method discussed above, there are a few other ways of creating this yeast starter. One such method is known as kimoto. As mentioned above, until about 1920, all sake was made by mixing rice, koji, and water to a puree in order to help the yeast cells reproduce faster. This was the original method, and since originally this was the only method there was, there was no name to differentiate it from other methods. Later, they needed to give it a name, and this name was Kimoto. Kimoto, then, is the original method. Indeed, even today, brewers creating sake made using a kimoto yeast starter will stand around a small tub and mix, mix, mix in a rhythmical, robotic action to mash up the rice, koji and yeast to a paste-like consistency. Monotonous and tiring work to be sure, but aren't all traditional methods? This activity, by the way, helps speed up the natural production of lactic acid in the moto. Lactic acid will then protect the developing moto from stray bacteria that would contribute to strange flavors or even spoil the sake. A kimoto yeast starter takes a bit longer than yamahai to create, but ironically, the sake that results from these two methods is similar in flavor profile. Like sake brewed with yamahai moto, sake brewed with a kimoto moto has a higher sweetness and acidity, with richer, deeper, significantly more pronounced flavors. Bitterness in the recesses is not uncommon. As with all sake brewing methods, though, the moto used is only one factor. In fact, the intention and skill of the brewer will dictate more about the final product than how the yeast starter was created.

 

Glossary of Terms

甘口	Amakuchi	Sweet in flavor
普通酒	Futsu-shu	Normal sake -- anything without a special monicker
原酒	Genshu	Undiluted sake (most are slightly diluted)
吟醸酒	Ginjo-shu	Sake brewed with rice  milled so that no more than 60% of the grain remains
火入れ	Hi-ire	Pasteurization
本醸造	Honjozo	Sake to which a small amount of distilled alcohol is added
地酒	Jizake	Sake from smaller kura -- originally, sake from the boonies
純米酒	Junmai-shu	Sake brewed with only rice, water, and koji -- no additives
辛口	Karakuchi	Dry in flavor
粕	Kasu	The lees remaining after  the sake has been pressed from the fermenting mixture
麹	Koji	Rice onto which koji-jin  has been propogated (see FAQ page, Q14)
麹菌	Koji-kin or Koji-kabi	Aspergillus Oryzae -- a  starch dissolving mold
蔵	Kura	A sake brewery -- also  known as a sakagura
蔵人	Kurabito	A brewery worker
蔵元	Kuramoto	Head of brewery
銘柄	Meigara	The 'brand name' of a sake
諸味	Moromi	Fermenting mixture of rice, water, koji, and yeast which yields sake
元	Moto	The yeast starter of a  batch of sake -- also, shubo
日本酒度	Nihonshu-do	The specific gravity of a  sake -- an indication of dryness or sweetness (see FAQ Page, Q16)
精米	Seimai	Rice polishing (milling)
精米歩合	Seimai-buai	The degree to which rice  has been polished before brewing
清酒	Seishu	The official name (as far  as taxes are concerned) for sake
焼酎	Shochu	A traditional Japanese  distilled beverage
酒母	Shubo	The yeast starter for a  batch of sake
杜氏	Toji	The head brewer at a kura