Process

A grain of rice.
A drop of water.
Eleven stages of Sake brewing.

A grain of rice.
A drop of water.
Eleven stages of Sake brewing.

1. Rice Growing / Harvest

Kome and Shukaku 米と収穫

Rice grows Spring to Summer and is harvested in late August to late September. Premium sake is made with sake-specific rice, which is larger than eating rice. Sake rice is difficult to grow as it is taller than other types of rice and therefore easily damaged by wind. Each region has a different variety of rice. The most popular types of rice for sake are Yamadanishiki and Gohyakumangoku.

2. Rice Milling

Seimai 精米

This process removes any dust from polishing and adjusts moisture levels to allow optimal penetration of water during steaming. The aim of rice polishing is to remove the outer layers of rice to reach the core starch, producing elegant aromas. Modern rice milling machines can control polishing ratio, speed and temperature, however human judgement is still the most important part in the rice milling process.

3. Washing / Soaking

Senmai and Shinseki 洗米と浸漬

Rice is soaked to achieve an optimal level needed for perfectly steamed rice. The time spent in water is monitored to a fraction of a second by using a stopwatch and visually checked. After soaking, rice is drained and put aside for several hours or overnight prior to steaming. For premium Daiginjo grade Sake, the rice is washed in small batches by hand, the traditional way.

4. Steaming

Mushimai 蒸米

Rice steaming is the first task at the sake brewery each morning. It is steamed for forty minutes to one hour to cook the rice evenly. The aim is for the rice to have a hard outside and remain soft on the inside. The Sake maker takes a small amount of steamed rice and checks it by shaping it into a small round cake in the palm of his hand. Steamed rice is transferred into the Koji muro (koji room) to make koji.

5. Koji Making

Koji Zukuri 麹づくり

Process takes 2 days. Once the Koji-kin is propagated, the Sake maker puts small amounts of rice into wooden boxes and keeps them at the desired temperature. Koji is steamed rice onto which a mould, called koji-kin has been cultivated. Koji mould works its way into the rice grains and releases enzymes to break down the starch. The starch in rice needs to convert to sugar so the yeast can ferment into alcohol.

6. The Yeast Starter

Shubo 酒母

Shubo means 'mother of sake', this is a super-concentrated fermentation starter. It has koji, steamed rice, water and yeast. This yeast starter is made in a small tank. Usually a small amount of lactic acid is used to make a suitable environment so that the yeast is protected from bacteria. This is the modern way to make Shubo, the traditional way is not to add lactic acid, but wait until it occurs naturally.

7. Main Fermentation / The Mash

Moromi もろみ

Shubo is then transferred into a larger tank or vat where rice, koji, and water are adde—this is the main fermentation process and takes around 3 to 4 weeks. The first 4 days of fermentation are called. Day one, the shubo, rice and water are mixed. Day two the mix is set to rest. Day three and four the volume increases and is then left to ferment into sake. Temperature is constantly monitored and adjusted.

8. Pressing

Shibori 搾り(上槽)

When fermentation is finished and the sake is ready, the newly borne sake is separated from the solid remains of the fermented rice. For high grade sake such as Daiginjo, a traditional press machine called ‘hune’ is used or a cotton bag is used to collect drips of sake. But generally sake breweries use a press machine to gently press the sake. New sake has a 20% alcohol level.

9. Filtering

Roka 濾過

After sitting for 10 days after pressing, the sake is filtered (Roka). Very fine powdered active carbon is used to eliminated unwanted colour and flavour. A recent trend with sake makers is to skip this process and keep the flavours more natural. This type of unfiltered sake is known as ‘Muroka’.

10. Pasteurisation / Maturation

Hiire 火入れ

Sake has no preservatives, instead it goes through a pasteurisation process, either by passing it through heated tubes or bottled and put into hot water for a period of time, then cooled. This is a more gentle process used for premium sake. The heating of sake during the pasteurisation process alters the aroma, leaving it with an unrefined taste. Sake is set to rest for 6 mths+ for it to settle and the flavours integrate.

11. Adjustment / Bottling

Chogo, Warimizu and Bindume 調合、割水、瓶詰

The heating of sake during the pasteurization process alters the aroma and leaves it with an unrefined taste, so sake is set to rest for 6 months or more, for it to settle and the flavours integrate. Sake brewers mature sake in different ways such as temperature controlled tanks, or in cool rooms.

1. Rice Growing / Harvest

Rice grows Spring to Summer and is harvested in late August to late September. Premium sake is made with sake-specific rice, which is larger than eating rice. Sake rice is difficult to grow as it is taller than other types of rice and therefore easily damaged by wind. Each region has a different variety of rice. The most popular types of rice for sake are Yamadanishiki and Gohyakumangoku.

2. Rice Milling

This process removes any dust from polishing and adjusts moisture levels to allow optimal penetration of water during steaming. The aim of rice polishing is to remove the outer layers of rice to reach the core starch, producing elegant aromas. Modern rice milling machines can control polishing ratio, speed and temperature, however human judgement is still the most important part in the rice milling process.

3. Washing / Soaking

Rice is soaked to achieve an optimal level needed for perfectly steamed rice. The time spent in water is monitored to a fraction of a second by using a stopwatch and visually checked. After soaking, rice is drained and put aside for several hours or overnight prior to steaming. For premium Daiginjo grade Sake, the rice is washed in small batches by hand, the traditional way.

4. Steaming

Rice steaming is the first task at the sake brewery each morning. It is steamed for forty minutes to one hour to cook the rice evenly. The aim is for the rice to have a hard outside and remain soft on the inside. The Sake maker takes a small amount of steamed rice and checks it by shaping it into a small round cake in the palm of his hand. Steamed rice is transferred into the Koji muro (koji room) to make koji.

5. Koji Making

Process takes 2 days. Once the Koji-kin is propagated, the Sake maker puts small amounts of rice into wooden boxes and keeps them at the desired temperature. Koji is steamed rice onto which a mould, called koji-kin has been cultivated. Koji mould works its way into the rice grains and releases enzymes to break down the starch. The starch in rice needs to convert to sugar so the yeast can ferment into alcohol.

6. The Yeast Starter

Shubo means 'mother of sake', this is a super-concentrated fermentation starter. It has koji, steamed rice, water and yeast. This yeast starter is made in a small tank. Usually a small amount of lactic acid is used to make a suitable environment so that the yeast is protected from bacteria. This is the modern way to make Shubo, the traditional way is not to add lactic acid, but wait until it occurs naturally.

7. Main Fermentation / The Mash

Shubo is then transferred into a larger tank or vat where rice, koji, and water are adde—this is the main fermentation process and takes around 3 to 4 weeks. The first 4 days of fermentation are called. Day one, the shubo, rice and water are mixed. Day two the mix is set to rest. Day three and four the volume increases and is then left to ferment into sake. Temperature is constantly monitored and adjusted.

8. Pressing

When fermentation is finished and the sake is ready, the newly borne sake is separated from the solid remains of the fermented rice. For high grade sake such as Daiginjo, a traditional press machine called ‘hune’ is used or a cotton bag is used to collect drips of sake. But generally sake breweries use a press machine to gently press the sake. New sake has a 20% alcohol level.

9. Filtering

After sitting for 10 days after pressing, the sake is filtered (Roka). Very fine powdered active carbon is used to eliminated unwanted colour and flavour. A recent trend with sake makers is to skip this process and keep the flavours more natural. This type of unfiltered sake is known as ‘Muroka’.

10. Pasteurisation / Maturation

Sake has no preservatives, instead it goes through a pasteurisation process, either by passing it through heated tubes or bottled and put into hot water for a period of time, then cooled. This is a more gentle process used for premium sake. The heating of sake during the pasteurisation process alters the aroma, leaving it with an unrefined taste. Sake is set to rest for 6 mths+ for it to settle and the flavours integrate.

11. Adjustment / Bottling

The heating of sake during the pasteurization process alters the aroma and leaves it with an unrefined taste, so sake is set to rest for 6 months or more, for it to settle and the flavours integrate. Sake brewers mature sake in different ways such as temperature controlled tanks, or in cool rooms.