Sake 101: A Beginners' Guide

🍶 What is Sake? Ingredients, Types, Varieties, and the Brewing Process

What is Sake?

Sake, Japan’s iconic traditional beverage, is often likened to wine due to its fermentation process, but it’s crafted from rice rather than grapes.

Unlike wine, which relies on the natural sugars in fruit, sake requires water and a unique mold called koji to transform rice starch into fermentable sugars.

Sake typically has its distinct character—a smooth texture, lower acidity, no tannins, and a slightly higher alcohol content than most wines.

For wine lovers eager to expand their horizons, sake offers a fascinating world of flavors and traditions waiting to be discovered. This beginner’s guide will walk you through everything you need to know, from its key ingredients to production methods and styles.

Let’s dive into what makes sake so unique and explore the elements that define this remarkable drink.

Sake Ingredients

The production of sake revolves around four key ingredients, each playing a vital role in shaping its character: rice, water, kōji, and yeast.

Rice

At the heart of sake is rice, but not just any rice will do. Japonica rice varieties are used. Among these, sake-specific-rice with round grains and large starch cores, prized for its purity and suitability for brewing. Yet it is used in only 2–3% of all sake due to its rarity and cultivation challenges. As a result, table rice still accounts for the majority of sake production in Japan.

Water

Unlike grapes used in winemaking, which naturally contain water, rice requires the addition of water during sake production—making up approximately 80% of the final product. Many sake breweries are located near pristine mountain streams or underground springs, where mineral-rich water contributes to both the brewing process and the flavor profile of the sake.

Kōji

Kōji mould is the powerhouse of sake brewing, driving the transformation of rice starch into fermentable sugars through the enzymes it produces. The type and quality of kōji play a crucial role in shaping the final flavor profile, acidity, and umami of the sake. Cultivating kōji is regarded as a highly skilled craft, essential to the artistry of sake production.

Yeast

Yeast is responsible for converting sugars into alcohol and carbon dioxide, shaping the aroma and flavor of the sake. Since rice, water, and kōji themselves are relatively neutral in flavor and aroma, yeast plays a critical role in defining the sake’s aromatic profile. Brewers often rely on specific strains isolated and shared within the industry, but innovative approaches—such as using indigenous or unconventional yeast strains from wine or cheese—are gaining popularity, adding new dimensions to sake production.

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How is Sake Made?

The sake brewing process is a meticulous craft, combining traditional techniques with modern innovation.

1. Rice Polishing
   The process begins with polishing the rice to remove the outer layers of protein and fat, revealing the starchy core. This step determines the rice-polishing ratio, a key indicator of sake quality. Premium sakes often use rice polished to 50% or less of its original size.

2. Washing and Soaking
   After polishing, the rice is washed to remove any remaining parts and soaked to achieve the optimal moisture level for steaming.

3. Steaming
   The rice is steamed in specialized vats, which gelatinize the starch molecules and prepare the grains for fermentation.—preparing it for fermentation.

4. Kōji prepration
   Kōji refers to steamed rice inoculated with kōji mould cultivated in a temperature- and humidity-controlled room. The koji converts starch into fermentable sugars.

5. Fermentation Starter (Shubo)
   The koji rice is mixed with water, yeast, and steamed rice to create the fermentation starter, known as shubo. This mixture develops a strong, healthy yeast population essential for main fermentation.

6. Main Fermentation (Moromi)
   Additional rice, kōji, and water are added to the shubo, creating the main fermentation (moromi) in three stages. This ferments for several weeks, producing alcohol and developing the sake’s unique flavors.

7. Pressing and Filtration
   Once fermentation is complete, the liquid is separated from the rice solids through pressing, which extracts the sake. Most sakes undergo additional filtration for clarity and to refine the flavor profile.

8. Pasteurization and Aging
   Most sakes are pasteurized to stabilize the product by deactivating enzymes and microorganisms. The sake is then aged for about six months to enhance its complexity. Before bottling, water is often added to adjust the alcohol content to the desired level.

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Exploring Sake Styles

Sake is broadly divided into two categories: basic sake (Futu-shu) and premium sake. Premium sake can only be made using rice, water, kōji mould, yeast, and, in some cases, a small amount of distilled alcohol.

Premium sake, which makes up about one-third of all Japanese sake, is often the preferred choice for wine enthusiasts. The rest is categorized as basic sake.

Unlike wine, which is typically classified by grape variety, premium sake is distinguished by two main factors:

1. The degree of rice polishing

2. Whether distilled alcohol has been added

Japanese sake labels are exceptionally beautiful, often featuring traditional imagery and calligraphy, but they can be challenging to decipher. Here are some key terms to help you navigate the categories:

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Junmai

Junmai, meaning "pure rice," refers to sake made without the addition of distilled alcohol. When distilled alcohol is added, it serves to subtly enhance aromas and lighten the body.

Junmai sake is generally full-bodied and savory, offering pronounced rice-like flavors.

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Ginjō

The rice-polishing ratio and the fermentation temperature are key factors in determining sake style.

When rice is polished to 60% or less of its original size, most of the proteins and lipids from the outer layers are removed, leaving almost pure starch. Sakes made this way tend to have delicate, clean flavors, a light body, and low acidity.

This style of sake is fermented at extremely low temperatures, often producing aromas of green apple and fresh banana. This type is called Ginjō.

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Daiginjō

Daiginjō is a more refined version of Ginjō, made from rice polished to 50% or less of its original size. This sake style is known for its elegance, with even purer and more delicate flavors.

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Honjōzō

Like Junmai, Honjōzō sake requires rice polished to at least 70% of its original size. The difference is that Honjōzō contains a small amount of distilled alcohol, which enhances the flavor and aroma.

Honjōzō sake is typically light-bodied and versatile, making it an excellent choice for beginners. It’s equally enjoyable whether served warm or cold.

This is the Japanese Sake Classification System.

With these basics, you're ready to dive into the diverse and fascinating world of Japanese sake!

The further detail will come soon.