Sake is made from rice but the enzymes that convert the starch to sugar are on the outside of the rice.  The outer shell of sake rice is removed before being introduced to the brewing process so sake brewers use a special kind of mold called Koji-kin to convert the starch in rice to sugar.  The thing that makes the sake process unique is that the process of converting starches to sugar occurs at the same time as the fermentation.  No other alcoholic beverage uses quite the same process as sake.

The rice used to make sake is called Sakamai and is very different than the rice that we eat.  Sakamai rice grains are 25% larger than table rice and are much more challenging and time intensive to grow.  The rice stalks grow very tall and due to the large size of the grains are prone to tip over and fall into the water in the rice paddy during storms which will ruin them.  This height means the rice must be harvested by hand rather than by machine.  Sakamai is also more susceptible to insecticides, and requires optimal growing conditions.  As a result of all these factors sake rice is three times more expensive than table rice.

The starches for sake rice are concentrated in the center of the kernel.  The proteins, minerals, and fats which can adversely affect the flavor of the sake are distributed on the outside.  For that reason sake rice is milled to remove the outer shell before the brewing process begins.  The milling of the rice must be done slowly and carefully as if it’s done too quickly, the rice will heat up which will adversely affect the flavor of the finished product.

The more of the outside shell that is milled away, the more pure the sake will be.  Premium sake is rated by different classes and a major determinant of class is the degree by which the sake is milled.  Junmai Dai Ginjo which is the highest grade of sake is made with rice that has had up to 65% of the rice grain removed.  The powder that is milled away is not wasted but is reused for livestock feed and consumer foods such as crackers.

After the rice has been polished it is washed and soaked.  The washing removes any remaining powder from the milling.  Soaking allows the rice to absorb water which is controlled very carefully in premium sake.  The amount of water absorbed by the rice will greatly affect how the rice dissolves during the fermentation process.

Once the rice has finished soaking it is steamed.  The rice must be steamed to a point where it is neither too mushy nor too firm.  After the rice is steamed it is spread out on large pieces of cloth to cool.

The next phase is a crucial one where some the rice (usually around 30%) is set aside and mixed with a special mold called Koji-kin.  The mold is sprinkled onto the rice and mixed over the course of two days.  The resulting mix is called Koji and it takes many years for a sake brewer to understand this part of the process.  Sake brewers typically do not sleep much if at all when the Koji is being made.

When the Koji is complete it is mixed with yeast and a small amount of lactic acid to protect against bacteria.  The yeast feeds off the sugars created by the Koji to begin the fermentation process.  Gradually more rice is added over a 2-3 week period to create what’s called Moto.

The Moto is then combined in much larger vats with the remainder of the rice and lots of water.  The rice and water are added in phases over a four-day period to create what’s called Moromi.  The Moromi is then allowed to ferment for 18 to 32 days.  The brewer must take care to stop the fermentation process at the proper time as too long or too little fermentation will dramatically impact the sake flavor.

The next phase is pressing.  Pressing has changed radically over the years and is automated in many breweries today.  In olden times the Moromi was put in cloth bags which were then put into presses and squeezed to eject the liquid which was in fact the sake.  Modern breweries use an accordion-like machine to press the sake but there exist breweries today that still use the manual method and many people find that the flavor is noticeably better.  Sake typically sits for 10 days after pressing to allow sediments to settle and chemical processes to finish.

The next step is filtering where the bits of rice are removed from the sake.  After this the sake is pasteurized by heating it to 150 degrees Fahrenheit.

Finally, water is added to the sake to bring its alcohol content down from its natural amount of 20% to around 16%.  Most sakes then age for 3-6 months before bottling.

This is an extremely simplistic overview of the brewing process.  Sake has been being made for thousands of years and the evolution of the brewing process is a complex and fascinating topic.  There are numerous web sites and resources that go into much more detail about the sake brewing process including:

http://www.sake-world.com/html/brewing-process.html
http://en.wikipedia.org/wiki/Sake

I hope this post was informative.  Next I’ll be reviewing a delightful little sake that I picked up locally and can’t wait to open.  Stay tuned.

Yama

The next time you’re at a sushi bar sharing a hot flask of sake between friends, or at a high-end sake bar sipping a daiginjo, keep in mind that the beverage you are enjoying has a history dating back several thousand years.

Sake is Japan’s national drink but had its origins in China at around 4,000 BC.  Sake came to Japan around 300 BC when the practice of wet rice cultivation was introduced.  In the 1300’s mass production techniques evolved and sake became Japan’s most important drink

The brewing process has been refined over the thousands of years since Sake was first invented, and as a result there are many different types of sake today.  From super premium to table sake, there is a sake for every budget and taste.  Some important types of sakes include:

Jumnai Only rice polished down to 70% of its original size.  Koji (mold to initiate the fermentation process), Koji Rice, and water are used as the ingredients.  No brewing alcohol, sugar, or anything else has been added during its brewing.

Junmai Daiginjo Considered one notch above the Junmai-type.  The rice used in making any sake labeled as the Ginjo-type must be polished down to at least 60% of its original size.

Junmai Daiginjo Considered to be the ultimate achievement of sake brewing, the rice is polished down to at least 50% of its original size.  This type typically has a light and mildly dry taste, and a delicate fragrance not found in most sakes.

Honjozo During the brewing of Honjozo, raw alcohol (100% alcohol) is added to the mix of mold, rice, and water (this mix is called Moromi).  The raw alcohol interacts with the elements of the mash resulting in a mild yet rich-tasting sake.

Daiginjo Shizuku Somewhat time consuming to brew, this special sake is allowed to slowly drip from its mash, aided only by the force of gravity.

Genshu Genshu means “raw sake”.  After filtration, unlike most sake, it is pasturized without reducing its alcohol content with water.   Genshu is 20% alcohol compared with most sakes which are 14-17%.

Nigori “Unclear Sake” where a course filter is used which allows some of the minute rice and koji particles to flow through with the finished product giving it a milky appearance.  With a medium heavy body, it has a slightly sweeter taste due to traces of sugar left in the particle.

Taru Sake Also known as “Cask Sake”, it is aged in wooden casks (traditionally cypress) to impart some of the color, taste, and aroma of the wood into the sale.

Nama Sake Literally meaning “fresh” or “living” sake, it is bottled immediately after filtration and is unpasteurized.  The yeast is still active giving it a tart, zesty flavor.  It usually has a light lemon flavor with a tinge of green.

Koshu “Old Sake” as this is called, is aged in sealed ceramic vats for an average of three years, and sometimes longer.

Kijoshu Sake that is made by replacing half of the water used in the brewing process with sake.  It is extremely heavy and sweet and is usually served as an aperitif.

I hope everyone has a great labor day weekend.  I’m planning a trip to Korea in October and am looking forward to exploring the sake scene in Seoul.  If anyone has any tips or recommendations I’m all ears!
Mtn.

“The History of Sake” was used as a source for some of the material in this post.  http://www.asianartmall.com/historyofsake.htm