SAKE 101

Sake, pronounced SAH-keh, is an alcoholic beverage made from rice. The production of sake is unique, creating the highest naturally occurring alcohol content of any fermented beverage (15-17% abv. on average). Sake is predominantly produced in Japan, however, it can be produced anywhere in the world.

WHAT IS SAKE

Sake, like wine and beer, is a fermented beverage. Sake production is different than wine production as sugar is not readily available in rice, as it is in grapes. Sake production is similar to beer production as rice has starch within the grain that needs to be converted into fermentable sugars. Similar to both wine and beer, once sugar is available, alcoholic fermentation is conducted by yeast. The below sections will break down the unique production of sake.

THE MAIN INGREDIENTS

Sake is required to be made from four main ingredients: rice, kōji, water, and yeast.

RICE:

Rice is the base ingredient for sake production. After rice is harvested it must be prepared before it is ready for sake production. The preparation steps for the rice are: polishing, washing, soaking, and steaming.

POLISHING:

  • Polishing is the removal of unwanted, exterior layers of the rice grain.

  • After the rice is harvested it has a hard exterior shell known as a husk. The husk must be removed to access the rice grain. Once the husk is removed the layer below is known as the bran. The bran has a brown color, rice with the bran is known as brown rice. The bran layer is not desirable for sake production and is also removed. Now that the bran is removed, the rice is now white rice. 

  • Now we have the choice of polishing down the white interior layers, known as the endosperm. These layers are full of nutrients which result in a sake with rich, savory flavors. The more we polish these layers down, the more delicate and clean the sake will be. Based on the percentage we polish the grain, we can label our sake with these unique names:

    • HONJŌZŌ: if 70% or less of the rice grain is remaining, meaning 30% or more of the grain was polished away.

    • GINJŌ: if 60% or less of the rice grain is remaining, meaning 40% or more of the grain was polished away.

    • DAIGINJŌ: if 50% or less of the rice grain is remaining, meaning 50% or more of the grain was polished away.

  • The core of the rice grain is full of starch and is known as the shinpaku.

Rice Diagram

HUSK: hard exterior shell

BRAN: brown exterior layers

ENDOSPERM: white interior layers

SHINPAKU: starch center

 

 

WASHING:

  • Once we polish the rice grain, there is a fine dust of rice particles on the rice grain.

  • These particles were intentionally polished away and need to be removed.

  • Washing the rice grains ensures that all rice grains are clean and free of residue.

SOAKING:

  • Rice grains are hard to protect the starch center. 

  • We must soak the rice to encourage the absorption of water and softening of the grain.

STEAMING:

  • Once the rice has absorbed water, heat will be applied to make the grain malleable. 

  • Heat is applied in the form of steam which softens the rice grain and allows enzymes to access the starch core.

  • Steaming also allows the rice grain to break down during fermentation.

Once the rice is steamed it must be cooled down. After the rice is cooled, 2/3 of the batch will be used for fermentation and 1/3 of the batch will become kōji.

Sake Polishing Machine

Polishing Machine

Sake: Polishing Stones

Polishing Stones

Sake: Rice Washing

Rice Washing

Sake: Traditional Rice Steamer

Traditional Steamer

Steaming Machine

 

 

WHAT IS KŌJI:

Kōji is steamed rice that has had the starch within converted into sugar.

Once the batch of steamed rice is cooled, 1/3 of the batch will go into a warm, humid room known as a kōji muro. The steamed rice will be laid out on long beds in a thin, even layer. The brewer workers will sprinkle mold spores, known as kōji-kin, over the top of the rice. The moisture of the rice and the humidity in the room will encourage the mold to grow. As the mold grows, it releases enzymes that convert the starch within the rice into fermentable sugar. Over the course of two days, the brewery workers must take special care of each batch to make sure the mold grows evenly. After two days, the room is cooled down to halt the growth of the mold. The steamed rice is now covered in a white, powdery mold, and tastes sweet with aromas of roasted chestnuts. This batch is now known as kōji.

Polished Rice

Steamed Rice

Kōji

Sake: Koji Muro

Kōji Muro

Kōji Muro and Kōji

 

 

WATER:

Sake is 80% water and requires high quality water to make high quality sake. Hard water and soft water are both suitable for sake production. The softer the water, the more delicate the sake will be.

YEAST:

Once the starch in the rice grain has been converted into sugar, it is the yeast's responsibility to convert that sugar into alcohol. Sake yeast is similar to wine yeast, however, they have been bred to be more alcohol tolerant. This allows for the yeasts to continue to convert sugar into alcohol after the batch has reached 15% abv. 

HOW SAKE IS MADE

Now that our rice and kōji is prepared. We can build the fermentation starter, known as the moto. Similar to making bread, a starter must be created to ensure a healthy population of yeast can carry out the fermentation. Once the starter is complete, and the population of yeast is healthy and strong, the starter is moved into a large vessel. In the vessel we will add a combination of steamed rice, kōji, and water three separate times over the course of four days. This three step process, is known as sandan jikomi.​ This process ensures the main fermentation mash, known as the moromi, is large and strong enough to begin fermentation.

FERMENTATION:

During fermentation, enzymes in the kōji are converting starch in the steamed rice into sugar at the same time yeast is converting any sugar in the vat into alcohol. This process of simultaneous conversions is known as multiple parallel fermentation, and is unique to sake production.

While the yeast is converting sugar into alcohol, it is also creating carbon dioxide, heat, aromas, and flavors. Brewers can choose between a variety of yeasts all of which perform uniquely and create their own aromas and flavors. An important factor during fermentation is temperature. Warmer fermentations create a richer and more savory styles of sake. Cooler fermentations create a more delicate, fruity, and floral styles of sake.

OPTIONAL ADDITION OF DISTILLED ALCOHOL:

Once the batch has finished fermentation, the brewer typically adds distilled alcohol to the vat. This addition is not to raise the alcohol level, rather it is to preserve the integrity of the brewer's work. Aroma and flavor compounds in sake are more soluble in alcohol than in water. This addition ensures that all aromas and flavors carry through to the final bottled product. The addition of distilled alcohol also lightens the body, creating a more delicate style of sake. If a sake has not had distilled alcohol added to the batch, the brewer will indicate so by stating "junmai", meaning pure, on the label.

PRESSING:

Once the fermentation is complete, the liquid needs to be separated from the rice solids in the tank to legally be called sake. This can be conducted by three separate methods. First is by an automated machine, known as a Yabuta, this is the industry standard as it is fast and precise. The second method is using a traditional press known as a fune. This requires extra labor and time and is typically only used for premium sake. The final method is by gravity which is extremely laborious and time consuming and typically only used for competition or super premium sake.

FILTRATION:

After pressing, sake has a slight yellow-green color. Most sake is filtered with activated carbon to remove the coloring components and create a clear sake. If a sake has not been carbon filtered, the brewer will indicate so by stating "muroka", meaning not carbon filtered, on the label.

OPTIONAL ADDITION OF WATER:

Once fermentation is complete, the alcohol level of the batch is typically between 17-20% abv. Most sake is diluted after filtration with water. This brings the alcohol level down to roughly 15-16% abv. and creates a smoother drinking experience. If a sake has not been diluted, the brewer will indicate so by stating "genshu", meaning undiluted, on the label.

PASTEURIZATION:

Pasteurization occurs for almost all sake produced. This process rapidly heats the sake to kill any active microorganisms and creates a stable product. If a sake has not been pasteurized, the brewer will indicate so by stating "nama", meaning unpasteurized, on the label. Nama sake must be treated similarly to milk, keep it refrigerated and consume it quickly.

STORAGE:

After bottling, the sake is typically stored for roughly six months prior to release to allow the sake to become optimally balanced. If the sake is stored for over two years, it is known as koshu, or aged sake.

CLICK THE PICTURE BELOW TO BE LINKED TO A VIDEO BREAKING DOWN THE PRODUCTION OF SAKE:

SAKE STYLES

Now that we understand how sake is made, lets dive into the most common styles of sake.

FUTSŪ-SHU:

Basic or entry level sake. This grade of sake has minimal regulations: it does not have a polishing requirement, it typically includes the addition of distilled alcohol, and it permits the brewer to adjust the final flavor of the sake. Futsū-shu production is on the decline and is roughly 65-70% of all sake production, ranging from mediocre to great quality.

PREMIUM LEVEL SAKE:

Premium sake has strict regulations, it may only be made with rice, water, kōji, and yeast and may be permitted to have a small addition of distilled alcohol. Premium sake grades are dictated by the rice polishing ratio and typically become more delicate and refined as we go down this list. Premium sake is on the rise and is roughly 30-35% of all sake production.

JUNMAI:

  • No rice polishing requirement.

  • Only produced with rice, water, kōji, and yeast.

  • The addition of distilled alcohol is not permitted.

  • Styles vary per producer, however, typically are moderate in acidity, savory, and less fragrant.

  • If a brewer produces a bottle of Junmai that is more special than their typical bottling, such as it has specialty rice or a low polishing ratio, the brewer may indicate so by stating "TOKUBETSU JUNMAI" on the label.

    • ​Styles vary per producer, however, are typically more refined than a basic Junmai.

HONJŌZŌ:

  • 70% or less of the original rice grain remains (70% polishing ratio).

  • Produced with rice, water, kōji, and yeast

  • The addition of distilled alcohol is allowed.

  • Styles vary per producer, however, typically are moderate in acidity, savory, and less fragrant.

  • If a brewer produces a bottle of Honjōzō that is more special than their typical bottling, such as it has specialty rice or a low polishing ratio, the brewer may indicate so by stating "TOKUBETSU HONJŌZŌ" on the label.

    • ​Styles vary per producer, however, are typically more refined than a basic Honjōzō.

JUNMAI GINJŌ:

  • 60% or less of the original rice grain remains (60% polishing ratio).

  • Only produced with rice, water, kōji, and yeast.

  • The addition of distilled alcohol is not permitted.

  • Styles vary per producer, however, typically are low in acidity, delicate, and fragrant.

GINJŌ:

  • 60% or less of the original rice grain remains (60% polishing ratio).

  • Produced with steamed rice, water, kōji, and yeast.

  • The addition of distilled alcohol is allowed.

  • Styles vary per producer, however, typically are low in acidity, delicate, and fragrant.

JUNMAI DAIGINJŌ:

  • 50% or less of the original rice grain remains (50% polishing ratio).

  • Only produced with steamed rice, water, kōji, and yeast.

  • The addition of distilled alcohol is not permitted.

  • Styles vary per producer, however, typically are low in acidity, delicate, clean, and fragrant.

DAIGINJŌ:

  • 50% or less of the original rice grain remains (50% polishing ratio).

  • Produced with steamed rice, water, kōji, and yeast.

  • The addition of distilled alcohol is allowed.

  • Styles vary per producer, however, typically are low in acidity, delicate, clean, and fragrant.

SPECIALTY SAKE:

These specialty sakes can be made with any of the above entry level or premium level grades of sake.

KOSHU:

  • Aged sake.

  • Koshu is not legally defined, however, typically it is aged in the brewery for a minimum of two years.

  • As the sake ages:

    • The texture becomes more rounded.

    • More savory and earthy notes develop along with increased richness and complexity.

    • The color darkens with time turning from clear to yellow to amber.

NAMA:

  • Unpasteurized sake.

  • Nama is fresh, vibrant, and uniquely aromatic.

  • Due to active microorganisms, nama sake should be stored at chilled temperatures and consumed quickly.

NIGORI:

  • Cloudy sake.

  • Nigori sake is filtered through a coarse mesh filter that allows some solids to pass through.

  • Resulting in a cloudy, white sake with a fuller body and richer texture.

  • Sweetness levels vary from dry to sweet depending on the producer's style.

  • Due to contact with the solids, nigori sake has a reduced shelf life and should be stored at cool or chilled temperatures and consumed within a year.

SPARKLING SAKE:

  • Sparkling sake can be created in several ways:

    • Injected carbon dioxide into the sake (not common, poor quality)​.

    • Capturing the carbon dioxide during fermentation in a closed tank (good to high quality).

    • Capturing the carbon dioxide during fermentation in a bottle (good to high quality).

  • This style is typically lower in alcohol (5-10%) and on the sweeter side.

TARUZAKE:

  • Sake that is aged in Japanese cedar vats.

  • Typically the sake is aged for one to two weeks as Japanese cedar is very fragrant.

  • Cedar alternatives such as planks, chips, etc. are not permitted.

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