Archive for August 2010

The Sake-Brewing Process (Part 3)

August 30, 2010

For information on the first steps of sake brewing please visit part one and part two of the sake brewing process.

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.

Changes Over the Years
Over the centuries, there were many adjustments and changes to the sake brewing process. These arose to either make better sake, or to make sake more economically. Sometimes, advances in the economic forum also lead to improved sake quality.

One of the most important advances was the improvement in rice-polishing equipment. Originally, rice was stomped in a vat to remove the husks. Later, water wheels and grinding stones were used. Today, there are great computer-controlled machines that will polish off the specified percentage of the outside of the grains, and do it in a specified amount of time (with longer being better). This minimizes damage from friction heat and cracked grains.

Another major advance was the use of ceramic-lined or stainless steel tanks, now the standard, over cedar tanks, which were used for hundreds of years. This has drastically improved the quality and purity of sake since the beginning of this century.

Then there is the pressing stage. Until the early 1900’s, all sake was pressed by pouring the moromi into canvas bags which were then put into a large wooden box called a fune. The lid was then cranked down into the box, squeezing out the sake. Now almost all sake is pressed with a huge, accordion-like machine that squeezes the moromi between balloon-like inflating panels, making disposal of the lees (called kasu) simple.

Almost all breweries will still press some of their best sake in the old way, using a fune. It does make noticeably better sake. But the accordion-like machine (called an Assaku-ki) is so much more efficient, and the fune so labor intensive, that the trade-offs are only worth it for top-grade sake.

Most controversially, however, is the koji making equipment. It is truly amazing how the slightest differences in koji can affect the flavor of the final product. Traditionally, koji is all made by hand in wood-paneled rooms kept warm and humid. As this is such a labor-intensive step, many changes have come about, and a lot of them are rejected later. (It is interesting to note that almost all super premium sake like daiginjo is made using hand-made koji.)

There are now large machines that will perform part or all of the koji making process, doing the work of several individuals.

Visual Explanation
If you would like an even more in depth look at brewing sake take a look at the Sake Production Slideshow, an indispensable tool to help you visually understand how sake is made. Confused by some of the terminology?  Get the Sake Dictionary, a downloadable guide to Sake terms, there’s also an iPhone app, so you can easily look up terms when you’re on-the-go!  Plus, if you’d like to sample more than 90 varieties of Sake, join me at the Sake Professional Course  in Portland, Oregon on November 7, 8 and 9. For more information, click here, or email us at info@sake-world.com.

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The Sake-Brewing Process (Part 2)

August 23, 2010

For information on the first steps of sake brewing please visit part one of the sake brewing process.

Koji Making (Seigiku)
This is the heart of the entire brewing process,  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 where 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.

The yeast starter (shubo or moto)
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 steaming and koji making 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 – 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.

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.

More to come
There are some final steps to brewing sake that will be covered in next weeks’ post. If you would like an even more in depth look at brewing sake take a look at the Sake Production Slideshow, an indispensable tool to visually understand how sake is made.  To learn more about Sake and sample more than 90 other varieties of Sake, join me at the Sake Professional Course in Portland, Oregon on November 7, 8 and 9. For more information, click here, or email us at info@sake-world.com.

The Sake-Brewing Process (Part 1)

August 16, 2010

The many steps of the sake brewing process are so inter-related, yet with each one constituting a universe unto itself, it is close to futile to try to put it into a few words. But we must try and the simplest of overviews would look something like this;

Steamed rice and koji (rice cultivated with koji mold, technically known as aspergillus oryzae) are first mixed with yeast to make a yeast starter, in which there is a very high concentration of yeast cells. After that, more rice, koji, and water are added in three batches over four days. This mash is allowed to sit from 18 to 32 days, after which it is pressed, filtered and blended.

This would be enough to get you through most conversations. But let us look at the process a bit more closely. Here are the main steps and processes:

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 not too much heat is generated (which adversely affects water absorption) or not crack the rice kernels (which is not good for the fermentation process).

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.

More to come
There are many other steps involved in brewing sake that will be covered in future posts. If you would like an even more in depth look at brewing sake take a look at the Sake Production Slideshow, an indispensable tool to visually understand how sake is made.

What is Sake, Actually?

August 9, 2010

Thought it was time to go back to basics for new readers and give you veterans a little refresher to remind you how sake is produce and how it differs from other drinks.

Many liken sake to wine as it is not carbonated and has a similar alcohol content, others to beer since it is made from a grain. Technically, it is more like beer but no reason to split hairs, let’ just allow it to have its own category, sake.

Looking at how wine, beer and sake are brewed should make it more clear just what sake is.

Wine is a fermented beverage. Fermentation is the process in which yeast converts sugar to alcohol and carbon dioxide, which in the case of wine, is allowed to escape. Sugars are already present in the grape, and these sugars are ready for use by the yeast cells as food and nutrients. Although this simple and short explanation does not do justice to the age-old art of making wine, it serves our purposes here.

Beer calls for another step. There is no fermentable sugar in barley grains, only long starch molecules that must be broken down into smaller sugar molecules, some that will ferment and some that will add to the flavor in other ways. Several other steps are also necessary:

  1. The barley must be malted. The grains are moistened and warmed to start the germination process. This creates enzymes that patiently wait in the grain for their opportunity to create sugar from starch.
  2. The malted barley grains are cracked and mixed with water, and kept at specific temperatures for periods of time. This activates the enzymes, which chop the starch molecules into smaller sugar molecules, a process called saccharification.
  3. After these sugars come into being, yeast is added, and fermentation is allowed to proceed.

Sake is also made from a grain; rice. However, the enzymes that break the starch molecules into fermentable sugars in sake making come from koji, which is steamed rice that has been carefully cultivated with a mold called koji-kin, Aspergillus Oryzae in English.

This magical mold eats its way into the rice grains, and chops the long starch molecules into smaller molecules that can be used by the yeast cells as food. The resulting mixture is put in the same tank with the yeast and more steamed rice, so that sugars are being produced by the koji and fermented by the yeast in the same tank at the same time. This has been dubbed “multiple parallel fermentation” a direct translation of “heiko fukuhakkoshiki.”

That’s just an overview. The process itself, however, is complex. It is very difficult to convey in a few words what people spend a lifetime learning.

So to learn more about Sake production, purchase the Sake Production Slideshow; a 15-minute, gorgeously presented slideshow of the sake production process, indicating every step from rice production and milling to rice cleaning and steaming to koji propagation to yeast starter to mash to bottling — all done in traditional old breweries in Japan.