Sake Production: The Basics

To speak of Sake in simple terms is like speaking about the simplicity Rachmaninoff’s Piano Concerto No. 3 – it just can’t be done. There are just too many technical attributes that must be considered if you are to discuss the production methods of this great beverage. Sake is by no means simple; it is one of the most difficult, regimented beverages to make.  But, as regimented as it is, we must also speak about how many variations on the same theme of production there exists - it’s like following Muddy Waters around the U.S. and listening to how many ways he can play “Hoochie Coochie Man.”  I have visited my share of Sake breweries in my life, but after spending time with some of the best in the business, learning as well as doing my fare share of production, I have a newfound respect – along with just a little bit more information. So I will do best to walk you through a very complex process, in the simplest of terms, from a Sommelier’s point of view. 

    

Now to the meat and potatoes of production (or the fish and rice):  There is one thing that does remain constant between all of the sake producers – timing. The art of organization truly is the key. One must be an incredible taskmaster to be able to make sake.  As I take you through these steps I will stop for a moment to give you “Variations on a theme.” These are places through the process that must be done at around the same time, but this is where the artistic license comes into play. This blog, or stream of conscience, is not meant to be an insanely detailed timeline into the production methods, but more of an insight about all of the components that add so many variables into the production. With wine with think of clones, wood, green harvest…. With Beer we have grains, different hops, yeast, water…

 

Rice. Not much more needs to be said when it comes to the ingredient that defines sake.  It is used for the ferment, the starter, the koji, as well as the base to grow the mold that makes koji, koji-kin. There are many types of rice that can be used to make sake, but Yamada Nishiki is the rice that is TYPICALLY used to make the best sake’s. I stress the word typically, because there are also some great sake’s that are made with other, sometimes local, varieties of rice and they should not be overlooked.  I have come to find that something so precise has so many variations. To quote John Gauntner, by far one of the leading experts of sake “There are 10,000 different ways to make sake, and not one is better than the other – just different.”  So, in many ways, Yamada Nishiki is the best rice (but not always).  My first recommendation: After trying a sake you should look up the producer and their location, then find out what type of rice they use. You will find that many will use Yamada Nishiki, but you will also find that the rice will change regionally.

There are two important steps to the rice before it can be made into sake - milling and steaming.

Milling: Of course we all know that the more that the rice is milled the better quality the sake. This is true but needs more definition. The rice that is used as the ferment will make better quality sake the more it is milled. Milling gets rid of the proteins that will add less than desirable flavors. But, the rice that is used to make koji is typically always milled the most to make the best koji.

Equally important to the milling is how it is steamed. Moisture content before and after the steaming of the rice will give different characteristics to the rice and koji, and therefore the sake.

Step 1: Rinsing and soaking

Rice is taken from the premeasured bags, usually 50lbs or another set weight, and rinsed for a set amount of time, then soaked for a set amount of time.  This is to achieve specific moisture content in the rice, which will help the rice steam consistently. After soaking the set amount of rice is weighed, and by post-soaking weight they can tell the moisture content. Due to relative humidity and outside temperature they may adjust the soak time to change moisture content to the desired percentage. This process is very rigorous, as the start times to each rinse and soak has to be very specific. One mistake and they will change the board to reflect time changes. It is also a very time consuming process, as they must do this in small quantities for a lot of rice.

There are many different types of yeast that are used in the production of Sake, I recommend going to www.sake-world.com to see a comprehensive list.  Some rice yeast, some flower yeasts, as well as what they call foaming and non-foaming. The type of yeast can drastically change the flavor and aromas of the sake. Foaming vs. Non-Foaming – these are exactly what they sound like. The foaming yeast causes the ferment, or Moromi, to foam up during fermentation. Many believe that these yeasts make more flavorful sake, but they do require more work, as you need to scrape the foam off of the sides of the tank as to not allow for residue to aid in the formation of “Bad” bacteria. The non-foaming yeast takes this problem out of the picture. So, once again, not necessarily better – just different.

Probably the most special thing about the yeast is how the starter, or “Moto”, is produced and this is also where the organization really begins to be the most important.  Two weeks before you start to make the actual sake, you need to make the moto (2days before the moto is made the koji needs to be produced – we’ll talk about that later). 

To make the starter you need 4 things:

(Remember these things because you will use this for each step in the production)

 

Water, koji, rice and water are mixed together with a set amount of the propagated yeast. From here they are trying to propagate it further and get as many functioning yeast cells to make it through the fermentation while the koji simultaneously converts the starch in the rice into sugar.  Temperature is by far the most important factor in propagating the yeast.  From the picture of the chart you can see they spike up the temperature to get the yeast going, then it is brought back down and then stair-stepped up. This is done to produce the highest quantity of viable and strong yeast cells, rather than producing many very quickly that will not make it through a longer fermentation.  So, at the end of the two weeks prior to fermentation you end up with strong and viable yeast, regardless of yeast type.

Koji is the miracle taskmaster of the sake production. It is the bases for the multiple-parallel-fermentation (What is that?). When all 4 elements listed above are added together there is no sugar for the yeast to eat. The koji makes fermentation possible. Koji (aspergillus orzyae) is the mold that converts the starch in the rice into sugar while the yeast simultaneously convert the sugar into alcohol.

First the rice is steamed. Then, the rice is broken up and cooled down by hand (Yes by hand, which for the first time can be a very painful process).  The rice needs to be taken care of my hand so that it can be broken up from bunches that occur naturally, from the rice sticking together, to achieve more surface area. After the rice is cooled a bit it is taken to the koji muro (koji room) and placed on a large table. From here, the rice needs to be brought down to 33 degrees Celsius (91.5 F).  (Variation Time: At one kura the temperature was brought down to 33 in about an hour, at another it was brought down to 33 over the course of 5 hours. Not better, just different). Important to note is that the temperature of the muro is usually hot and humid, with the temperature and humidity level varying depending upon the kura. During the cooling down process, the rice must be turned and broken up gently so it can dry consistently, as well as expose the most amount of surface area of each kernel of rice. After the desired temperature is reached the koji-kin is added. Koji-kin is the actual mold that is sprinkled onto the rice. This sprinkling process is very delicate and hence called “Tegiri - the dance, or cut, in Japanese”. A set amount of koji-kin is used for a set amount of rice. The koji-kin is sprinkled on the rice and then the rice is flipped over and the process is done again. The purpose is to distribute the koji-kin as evenly as possible. Another reason for allowing the rice to dry slightly on the outside is so the koji-kin works its way into the rice in search of moisture.

At this point the rice is now formed into a mound and covered with canvas. While the koji-kin propagates the temperature rises. The mound will be broken up and reformed to help distribute the growth evenly. (Variation Time: Different kura will do this at different intervals, amount of times, and temperature).  After a set time the mound is broken up and distributed into vented flats. The ventilation is to help keep the temperature consistent. After the ice is put onto the flat, some producers will put a circular design into the rice to also give a means for heat transfer and cooling. Important to note is that the size of the flat may vary depending upon the style of sake. Daiginjo koji will usually be made in smaller flats, whereas other styles are made in larger flats. From here the rice will remain the flat for another 30-36hrs. During this time the rice may be moved around, smoothed out, then the design drawn again to help with the consistency of growth. No after the two days are up you have koji. The koji will feel “fluffy” and have a white film on the outside. Its flavor will also be sweeter, yum!

We now have our moto, koji, rice and water. How does it come together?

 

Now that our sake is made it will go through a handful more steps before its release into the market. Depending upon sake styles these things may vary: Pressing, filtering, pasteurizing, bottling.

Check out the next blog on the way: What is done differently for the different levels of sake.