Want to know how premium Sake from Hakutsuru is made? This article describes each stage of the traditional methods used to create the handcrafted sake, specifically Daiginjo!
To find about more about Hakutsuru, check out our previous Masterclass blog here
The rice grain (Yamada Nishiki) must be large, hard and low in protein and for the clear sake taste - it is grown in Nadagogo and polished at 38% instead of the standard 70%, which requires delicate care to create the premium sake.
Sake Brewers - Kurabito, all start off with a morning stretch outside overhead speaker. They then wash and sanitise their hands, in a clean environment.
Each grade of rice is washed and soaked - this is a critical part in the process as every second counts. Even a 3 second extra soak can increase water content by 0.1% - this is known from hundreds of years of knowledge and experience. They can gage and infuse the water with each grain of rice in a carefully controlled process - using a timer for accuracy.
A day later, the rice goes through the steaming process (mushimai) - the rice is loaded into the rice steamer called koshiki, this holds approximately 350kg of rice in an hour, it allows the brewers to change the steaming temperature which takes skill.
The long fermentation process allows the koji to grow attaining a perfect balance. Brewers check the condition of the steam - they pay special attention to avoid ‘namamushi’ which are rice grains that aren't fully cooked. If hard uncooked rice gets into the ‘moromi’ and then the sake lees, it doesn't create good sake. It is all about team work during this process.
Removing the rice has to be done quickly to ensure the rice cools down properly. The rice is separated for different stages of the sake crafting production. The rice is extremely hot but the brewers still use their hands to spread it as it is the only way they can truly tell the conditions of the rice.
The perfect temperature to cool the rice is 40 degrees - the rice is moved to the ‘kojimuro’ where the koji is allowed to grow, like a sauna. It is rested for 2 hours, under strict conditions to make sure the brewers can detect the slightest of changes in the rice by feel and sight.
‘Tanekiri’ - the stage where the koji spores are spread onto the rice and are evenly distributed. The koji spores break down the starch and the sugar to make alcohol. Brewers massage the koji seeds onto the rice so each grain is coated, they then wrap the rice to keep in the moisture to help the mould grow. The table is also a scale, this is so that the brewers know how much water remains.
Overnight the rice naturally becomes harder and sticks together, brewers use their hands and sifters to separate each grain of rice called the ‘kirikaeshi’ process. Rice is then placed into wooden trays called ‘koji buta’ to further encourage koji growth - it is split into smaller piles which is easier to keep an eye on temperature and water content of each grain. This is to ensure the koji mould grows at the same rate.
The rice is then let to rest for a day and is monitored throughout the day and night, some brewers live in the brewery to check humidity, growth and water content. The hardest part of growing the koji mould is monitoring the conditions and environment, one miss calculation can result in the koji mould growing too fast or too slow. The detailed process is necessary to create the premium sake. The most important thing is to not disturb the koji growth, brewers have to be careful to maintain a high temperature and do the work quickly, making koji takes 48-50 hours and deciding when to cool it down is critical.
Rice to alcohol: matured rice koji, yeast, and water are mixed together. Mountain water with uniquely high mineral content is used - a key ingredient for the clean sake taste. Hakuturu uses their own special blend of yeast in the handcrafted sake. They have 400 different types of yeast, developing the exact flavour for each Sake.
The three ingredients are mixed together 3 times over 4 days. Their specific blending technique and ingredients create the perfect consistency. After nearly a month of fermentation ‘fukuro tsuri’ - hanging bags, filtering by hand. The final stage is the taste test and is approved for shipping.
