Sake (soc-KAY) is an alcoholic beverage brewed from rice that has been produced in Japan for over 2000 years. The term ‘Sake’ literally means ‘alcohol’ in Japanese so what we are actually speaking about is what the Japanese call: nihonshu which translates to ‘alcohol made from rice’. The application of this beverage ranges from ceremonial to an everyday libation. The quality, the styles and the flavors vary as much as in the world of wine.
All sakes are made using the time- honored, traditional methods that have been used for millennia. In the simplest terms, sake is produced using 4 ingredients: rice, koji, water & yeast. Different production methods and the introduction of additional grain alcohol offer different categories and levels of quality that affect the final product. Sake that is made with the original 4 ingredients is called Junmai. There is a parallel category to Junmai that has the addition of a 5th ingredient, grain alcohol, for increased texture and mouthfeel.
Sake is made in almost every prefecture of Japan. Similar to wine, regional factors suggest stylistic similarities but there are no AOC –type appellation laws to determine production methods or guarantee continuity of sake profiles of a particular zone. The rice, water, climate and cuisine of an area will have an effect on the finished style of the sake but owing the fact that rice is routinely imported from its region of origin effects the overall regional character. There is a movement to try to go back to traditional production of sake using locally sourced rice, water and yeast but due to demand and economic factors, this model is not widely embraced by the larger industry.
The first and main ingredient of sake is rice. There are 70 different rice varieties that are used to produce sake. These rice types differ from the rice on our dinner plate. Sake rice grains are larger with less protein and fat. There are four main species of rice used for sake production that make up nearly three-quarters of the rice plantings: yamadanishiki, omachi, gyohakumangoku, and miyamanishiki. Similar to grape varietals, different rice types offer differences of flavor and texture. The first two rice types pre-dates World War II and produce riper, more savory sake with a full body. The latter two rice varieties were developed in the post-war years to withstand the colder climates in northern Japan. These rice varieties offer clean, fresh flavors. However, popularity is gaining at smaller Kura (sake brewery) to use locally sourced or a single variety rice mash to make small batches of unique sake.
Sake production begins with the polishing of the rice. This process removes fats, proteins, and other compounds that give off-flavors. The amount of milling of the rice kernel dictates the type and quality- level of the sake. For all sake, the rice kernel has at least 30% of the husk (the outer portion) removed. The more polishing a kernel goes through the more delicate, refined and elegant the sake.
Sake Milling Chart
|Rice Milling %||ALCOHOL ADDED (Rice, Water, Koji, Yeast + distilled COH)||Pure Rice Style (Rice, Water, Koji, Yeast)|
|50% or less remaining||Daiginjo||Junmai Daiginjo|
|60% or less remaining||Ginjo||Junmai Ginjo|
|70% or less remaining||Honjozo||Junmai|
|No minimum requirement||Futsu-shu||XXXXXXXXXXX|
Once the rice is milled, it is washed to remove the ‘nuka’ or rice dust. Once rinsed, the rice kernels are then soaked for increased hydration. The soaked, hydrated rice is then put through a steaming process. This step is essential to change the molecular structure of the rice’s starch to be easily be broken down into yeast-edible sugars. The moisture within the rice grain is a critical component to the next step, the inoculation of the Koji-kin.
Since rice, unlike fruit, does not have easily accessible sugars for yeast to consume and therefore produce the desired alcohol, Toji (sake brewers) use the Koji-kin to help facilitate the transformation of starch into sugars. Koji-kin is a mold that releases enzymes that ferment food by decomposing its carbohydrates and proteins to break them down into sugars and amino acids. In the next step of production, 20% of the steamed rice is then transferred to a hot room with long tables. The rice is spread out on the tables to dry, slightly. Koji-kin mold spores are sprinkled onto the grains. The mold on the dry outside of the kernels breaches the outside coating of the rice seeking essential moisture and enabling growth. This initializes the transformation of the rice starch into fermentable sugar. It takes about 4 days for the mold to grow, flourish and convert the rice into a fermentable state. Once the inoculation is complete, this rice is called Koji-rice.
Preparations are now complete to create sake. The reserved steamed rice, Koji-rice, yeast and water are combined to start fermentation. The Koji-rice gradually converts the other rice’s starches into sugars which are converted into alcohol by the yeast cells. This is a natural process that lasts around 20 days until the mixture reaches 20% alcohol by volume.
Once the Sake reaches the 20% threshold, the yeasts die out and the fermentation is complete. The next step is for the sake to be pressed. The alcoholic liquid (the sake) needs to be separated from the rice solids and dead yeast cells. Before technology, the sake must would be placed in a porous bag and hung from a rafter allowing gravity to press the liquid from the must. Today, however, large pneumatic presses literally squeeze the liquid from the rice solids. This allows for maximum extraction of liquor from the mass. The rice solids are then used for cattle feed, composted or other culinary uses.
Fresh Sake has been created! It is from this point on that the different styles and types of sakes are created. After pressing the sake from the rice solids, the liquid has the option to go through further filtration to make the liquid clear. Should the decision not to filter the sake it becomes a Nigori sake. This style of sake leaves the rice particles and gives the sake a milky appearance. Most Nigori sake are slightly sweet.
The next step for most commercial Sake is pasteurization. This process quickly heats the sake to 150⁰F. The sake is run through a heated pipe until the desired temperature is achieved that deactivates enzymes, kills bacteria and any remaining yeast. This allows for the sake to be shelf stable without refrigeration If a Toji chooses not to pasteurize sake it is then called a Nama Sake that tend to be light and fruity.
After the sake has gone through these two steps, it is allowed to mellow in a tank for 3-6 months. There are sakes that are aged for longer and even in barrels or casks (Taru in Japansese). These are rare, but as interest grows for new sake options, these Taruzake are becoming more available in the United States.
When the sake is ready to be bottled, it is usually pasteurized again and then diluted with water to bring the alcohol content to about 15%. If a sake is only pasteurized once, it is labelled a Draft sake. If the choice is made NOT to dilute the sake, then it becomes a Genshu sake, which will carry the alcohol content of about 19-20%. The bottles are then capped, sealed and boxed for shipping!
Toji can decide to combine any of these techniques, so you might see a few of these terms on one sake. As an example: Nama Genshu will be an unpasteurized, undiluted option. Each of these expressions offer a different mouthfeel, flavor profile and overall tasting experience. I strongly recommend trying as many different types of sake as you can to find. As the Japanese say: there is a sake for every occasion!