What is sake?
Sake is an alcoholic beverage derived from rice and water that has gone through a fermentation process. Traditionally referred to as ‘Nihonshu’, this translates to “wine of Japan”.
History of Sake
Sake plays a major role in the rich history and culture of Japan, dating back to about 500BC. This ancient art-form has undoubtedly transformed over generations. Current methods of brewing sake are sophisticated and scientific in precision.
Temple-made sake is seen as a major revelation in sake brewing. Sake is an integral part of religion in Japan and unsurprisingly temples were the ideal place to start brewing sake. Temples not only owned rice fields with high production, but they also controlled the main water sources of a city. Not to mention they were filled with monks, which meant a devoted workforce.
Monks then became the guardians of sake. With sake left in the hands of the monks more advanced techniques in sake brewing and chemical differences in water were recognised. This allowed different qualities of sake to be made based on brewing technique. Thus, the famous Bodaimoto method was born.
The moto or seed mash is created by allowing naturally occurring yeast in the air to propagate on steamed rice. Next a small amount of this is combined with raw polished rice and water. This mixture is then left to incubate for about three days. During this process the mixture will start to bubble and a sour liquid is produced. At the end of the three day process, the mixture is strained. This sour liquid is to be used with steamed rice and koji in the main mash. Because this process produces a large population of lactic acid bacteria the resulting sake has a certain degree of tartness.
Pasteurisation was also discovered in this era. By heating up the end product, it would have a longer shelf-life. This meant the product could also be transported further away and could be consumed for longer post-production.
This critical time period in sake brewing saw a rise in varying brewing processes across Japan. Brews varied in both tastes and flavours. Some regions produced better sakes than others and word travelled.
Moving on from temple-made sake, to locally brewed sake.
How many types of sake are there?
There are five main types of sake, Junmai-shu, Honjozo-shu, Ginjo-shu, Daiginjo-shu, and Namazake.
Each type of sake arises from a different brewing method and seimaibuai otherwise known as the percentage of rice milling. Through changing these two characteristics, different flavour profiles are achieved.
Junmai-shu: pure rice wine, distilled alcohol is not added during the brewing process. Most junmais are polished between 30%-40%.
Honjo-shu: about 40% of rice is polished away and a small amount of distilled alcohol is added.
Ginjo-shu: at least 40% - 50% of the rice is polished away. When labelled Ginjo, distilled alcohol has been added. When labelled Junmai Ginjo, there is no added alcohol.
Daiginjo-shu: At least 50% of the rice is polished. Similar to the Ginjo, when labelled Daiginjo distilled alcohol has been added and when labelled Junmai Daiginjo, no alcohol is added.
Namazake: Is unpasteurised sake and can range from a Junmai to a Daiginjo.
How is Sake made?
Making the perfect sake is both an art and science. This process takes place in a kura (sake brewery), and is headed by a Toji which is in charge of the whole process. The kura-bito (‘brewery people’) on the other hand are the workers who man the breweries and warehouses. Traditionally, sake is made during winter when the rice farmers had finished harvesting crops and had extra time on their hands.
The three main pillars of sake brewing include, Seikiku which is preparing the koji mould or koji. Secondly, is creating the Moto or yeast starter. Third and lastly is making the fermenting mash known as the moromi for the fermentation process, referred to as tsukuri. As previously discussed changes to each brewing process along with the different degrees of seimai (polished rice), results in an array of flavours from only rice and water.
The sake making process begins by milling the rice grains to remove the husk. This process is known as seimai, and leaves behind the soft white grain of rice. The rice is then washed and soaked in water for a specific amount of time, as controlled by the toji. This process is important as the amount of water absorbed by the rice grain core affects the end product.
The rice is then transferred into a koshiki which is a large bamboo basket used to steam the rice. After the steaming process, the toji assesses the consistency of the rice by squeezing it into a ball, referred to as hineri-mochi. When the rice is of the right consistency, it is cooled as it is prepared for the next step in the process.
Long ago, seikiku was a laborious process which involved steamed rice placed in a room called a muro or koji-muro (koji culture room) which was high in both humidity and temperature. Koji mould spores were then sprinkled evenly over the rice by hand and would then be wrapped up in cloth. It would then be left in the muro to allow for the even propagation of the koji mould. After a few hours, the clumps of rice would then be gently broken up and divided into wooden trays called koji buta. This will allow the koji propagation to continue overnight. The koji buta were then emptied out and thoroughly mixed by hand. This process requires focus, patience, and concentration. When this process is done right, it allows for the even propagation of koji. Even today, some daiginjo sakes are made in the same way.
Currently, with the advancement of technology and knowledge the seikiku can be completed with the help of machines. Steamed rice and koji mould spores are placed in a koji-making machine that controls the temperature as well as mixing of the rice and koji mould. The process takes approximately 38 hours. Once complete the product is removed from the machine as ready to be used koji.
Another key ingredient in sake is the yeast starter that will be added to the moromi. Currently, most motos are made using a high quality of yeast with commercially available lactic acid. It has been referred to as “quick fermentation” method or sokujo-moto. This process yields results in approximately two weeks.
When preparing the moromi or fermenting mash, the steamed rice initially prepared, along with water are placed into a tank. The koji and yeast starter are then sequentially added to the mixture. The brewing of sake, especially Junmai sakes are unique in that during the fermentation process the moromi goes through “multiple parallel fermentation”. In which the koji converts the starch in the rice into glucose, whilst the yeast converts the glucose into alcohol.
Once the mixture has reached its optimum fermentation, it is ready for pressing or filtration, known as Assaku. Long ago, the moromi would be put into bags and the refined sake would slowly separate with the help of gravity. Alternatively, the bags were squeezed in a traditional stick lever-type press. The caked lees or sake kasu were then removed and the process done again.
Currently, the main mash is placed in an automatic press. This machine separates the moromi into ‘new sake’ and caked lees and can process about 80, 000 litres/day.
To increase the longevity of the sake, most are pasteurised and later stored before bottling. Unpasteurised sake known as namazake on the other hand must be kept at no more than 5°C, for the live cultures to survive.
Frequently asked questions
How long can I keep an open bottle of sake?
Sake is meant to be had fresh. But once opened, it will last for about 6 weeks. But we do recommend you finish it within 2 weeks as the flavour and fragrance diminishes.
How long can I keep an unopened bottle of sake?
Refrigerated and away from heat and direct light, sake can be kept for two years from the date on the label. Namazake are unpasteurised, therefore should be refrigerated in temperatures below 5°C.
What should I look for in a sake?
Clean refined flavour, crisp and refreshing.
When should I have cold or hot sake?
Junmai ginjos and junmai daiginjos are recommended to have cold.
How do I pronounce sake?
What is the difference between a junmai, junmai gingo, and junmai daiginjo?
The seimai or the percentage of polishing of the rice. Junmais are normally polished about 30% - 40%, junmai ginjos 40% - 50%, and junmai daiginjos are polished from 50% upwards.