The Brewing Process Of Quality Handcrafted Sake
1. Sourcing Ingredients
As with making any great beverage, making great sake starts with sourcing the finest ingredients. Sake is made essentially from water and rice, with the help of important catalysts yeast and koji spores. Koji spores are dusted onto some of the rice in order to convert rice starches into sugar, which is consumed by yeast to create alcohol.
At Ontario Spring Water Sake Company we use very special spring water from northern Ontario chosen for its suitability to sake production, and in fact this special spring water shares many chemical properties with the spring water used in the famous Fushimi sake brewing district of Kyoto. The rice we use is a fine sake rice produced in California, where our supplier mills the rice grains down to 70% of their original size in order to eliminate some of the harsher tastes produced by proteins concentrated in the outer layers of the rice grain. Special sake yeast and koji spores are imported from the same Japanese suppliers used by our brewing consultants, the venerable Miyasaka Brewing Co., Ltd. (established in 1662), brewers of the MASUMI line of fine sake.
2. Rice Washing And Soaking
Every production day a carefully measured amount of rice is washed and soaked in preparation for its steaming. While large breweries in Japan would normally (that is for all but the finest brews) measure, wash and soak rice for brewing by various machine processes, at Ontario Spring Water Sake Company we use traditional rice washing bags and tubs to achieve the perfect pre-steaming consistency, which is judged by texture of the soaked rice using the hands and experience of the brewmaster rather than a simple calculation of time.
After the washed and soaked rice is at the perfect condition for steaming, the rice is hand-loaded into our rice steamer, which was manufactured in Japan especially for the production of small- batch sake rice for the highest quality sakes (large breweries use mechanized continuous steaming systems). Unlike rice for the dinner table which is typically boiled in hot water either in a pot or automatic rice maker, sake rice is prepared by steaming, which allows the rice to maintain a firm outer texture and soft centre, thereby helping the brewing process.
4. Rice Cooling
When rice is taken out of the steamer it is very hot and must be cooled prior to being used in further stages of production. While in a large commercial sake brewery a refrigerated conveyor system is used to adjust the temperature of just-steamed rice, we are using traditional methods of rice tossing and kneading to adjust the temperature, which also allows the brewmaster to assess in detail the texture of the steamed rice and choose how to best use it within the brews.
5. Koji Making
The heart of a sake brewery is its “koji muro”, the cedar-lined room in which koji is made. Our koji muro is lined with western red cedar from British Columbia, which has a delightful aroma in addition to having natural anti-bacterial resins which help to create a clean environment conducive to efficient koji production.
Koji making is a 48-hour process which involves the inoculation of rice with koji spores, careful kneading and control of temperature and humidity, resulting in very sweet and white koji, ready for becoming about 20-35% of the rice used in the production of sake depending on recipe.
The operating temperature in the koji muro is typically 30-32 degrees Celsius, which makes for a challenging work environment for our brewery staff!
Once the first batch of koji is ready, it is time to start mixing it into chilled spring water and yeast in a fermentation tank, then adding steamed rice. The tank is filled gradually, in three stages over a 4-day period. This allows the yeast to retain its strength to keep consuming sugar and producing alcohol throughout the fermentation period, which typically continues for 21 days. Temperature within the fermentation tanks is carefully controlled using cooling jackets, as the sake’s pleasant tastes are enhanced by not allowing the yeast to act at its ideal productive temperature of 28 degrees Celsius, rather at a lower temperature ranging from 8-18 degrees depending on the stage of fermentation. The brew, called “moromi”, is carefully mixed by hand on a daily basis to ensure consistent fermentation. Each day tests are performed to check specific gravity, acidity and alcohol content.
7. Pressing And Racking
Once the moromi reaches completion as determined by the brewmaster, it is drained by gravity into cloth bags which are placed in the traditional “Fune” press which works with gravity and hand-applied mechanical pressure (in a large commercial brewery the moromi is machine-pumped into a large accordion like hydraulic press called a “Yabuta”). The first juice of sake starts emerging from a spout at one end of the press under the natural weight of the filled bags, resulting in a light-and-fruity first-pressed sake known “arabashiri”.
Gathering around the press and tasting the arabashiri is a reward to the brewery staff who have worked very hard to create the batch! It is also perhaps a treat to be savoured by those who visit our brewery on pressing days.
While large commercial brewers will usually add activated charcoal to the pressed sake and then mechanically filter the batch, we simply rack our pressed sake via siphon hoses, creating a 100% handcrafted sake for you to enjoy by the glass in our brewery or by the bottle wherever it is available!
Once pressed and racked the sake may either be bottled immediately or temporarily tank-stored at close to 0 degrees Celsius. Our small bottling operation is conducted entirely without pumps, relying on gravity to fill the bottles gently. We currently use two sizes of bottles, 300 ml and 1.8 litre, both imported from Japan. The dark brown colour of glass is used to best protect the sake from ultraviolet rays which damage the sake’s flavour and appearance.