OUR PROCESS
How Dassai Blue is made
A lot of time and effort put into a single glass or a single bottle.
From the standpoint of rationality and efficiency, it is not a good idea, but we believe that this "labor-intensive" process is very important.
And we don't believe that taking the time and effort = manual work only. We also use the latest technology, using data and not a black box.
Everything is for good sake.
How is Dassai Blue sake made?
1. Polishing rice
Dassai Blue exclusively uses the king of sake rice, Yamada Nishiki, and produces only junmai daiginjo that has been polished by more than 50%. In the rice polishing process, the outer layers, which contain proteins and fats that can cause off-flavors, are removed to create elegant sake.
The rice powder left after polishing is utilized as an ingredient in food products, ensuring nothing is wasted.
2. Washing rice
We rinse the white rice to remove the rice bran in 10 kg units in running water, then soaking in the water for about 15 minutes. We apply the “limited water absorption method” for all the rice we use. The important thing is to achieve the exact moisture content in the white rice, which is the first critical point in the production process. Moisture content has to be managed within a 0.1% tolerance of the target of each purpose for Koji or other use. The person in charge needs to keep in mind the amount of moisture naturally contained in white rice and fine-tunes the soaking time in seconds for each 10kg according to changes of environment, such as air and water temperature.
3. Steaming
We create Koji that sustains enzyme activity throughout the long fermentation period of 35 days for the MOROMI (mash). To do this, each grain of steamed rice must be finished with a hard exterior and a soft interior. We value the traditional method using Japanese steamers. Tasks such as placing the rice and retrieving the steamed rice require hard works, but they are necessary techniques for producing good steamed rice.
4. Making Koji
To make Koji as intended, experienced human hands are essential. However, rather than relying solely on the five senses and experience, we effectively use analysis technology to visualize and quantify the process, facilitating the sharing of information and unity of intentions among brewers. DASSAI faces Koji making by investing the necessary effort by human hands rather than relying on automation. We evenly sprinkle Koji mold onto the steamed rice. Koji continuously supplies glucose for yeast to play the fermentation, giving the mash its depth of aroma and taste, which is the most important role in the sake brewing process. Historically, it has been said, "First Koji, second starter, third fermentation." To express the aroma and taste of DASSAI, we ensure that the Koji mold spreads on each rice grain, allowing the Koji to grow into the core of the rice grain. Team members repeatedly handling koji rice in a hot and humid Koji room close to 40℃ (104℉) Machines cannot fully grasp the information humans perceive through their five senses and experience. Therefore, we value human hands for Koji making. Koji is a living organism, requiring continuous attention and caring for 55 hours, or two and a half days and nights, until completion. Because each Koji box has different status such as the growth of koji molds and temperature, it requires detailed adjustments tailored to their individuality. This demands the sensitivity and perseverance of the team in charge.
5. Fermentation
If washing rice and making Koji are compared to playing the violin or piano, the person in charge of fermentation acts as an orchestra conductor. Finally, it’s the climax. DASSAI features an entirely long-term low-temperature fermentation process for the mash. We start the main fermentation at a temperature of 41℉, which is close to the yeast's survival lower limit. Instead of seeking efficiency with larger tanks, we use small 5000-liter tanks. By making the tanks smaller, we can closely monitor temperature and fermentation situation, enabling us to continue to pursue the best delicious taste of DASSAI. Throughout the fermentation period of about 35 days, we do not choose a high product temperature in order to prioritize labor saving and safety. We believe it is necessary to control the fermentation mash at a low temperature with an accuracy of 0.1℉. Generally, it may be considered that such temperature control can be easily managed through mechanical means, but such simplified operations cannot respond to the actual fermentation conditions of each tank. In this scenario, it is also essential to collect the live information with human sensitivity and perform detailed, individualized caring.
6. Bottling&Pasteurization
The effort up to this point can be ruined during the pressing stage. Each brewing tool, such as hoses and pumps for transporting fermented mash and the press machine, can add off-flavors to the sake depending on how they are cleaned up. Cleaning the production site and maintaining the tools are mundane and persistent tasks, but they are fundamental basics necessary to craft delicious sake. The sake, once pressed, begins to deteriorate due to external influences like ultraviolet rays and oxidation. From this point, it becomes a race against time. We conduct multiple tastings the morning after pressing and promptly bottle the approved sake. After bottled and capped, we heat the sake in an ultra-short time of 3 minutes to deactivate the remaining enzyme components and bacteria, then store it in a super-cooled warehouse at 14℉（-10℃） for about 3 months to stabilize the sake quality before shipping.
