If you are new to sake, you may have heard it described as “Japanese rice wine”. That description sounds convenient, but it does not explain how sake actually works. So, what is sake made of, and is sake really a type of wine?
Sake uses a surprisingly short list of ingredients. Rice, water, koji mould and yeast form the foundation of most sake production. However, the way producers prepare and combine these ingredients makes sake unique.
For students beginning the WSET Level 1 Award in Sake, understanding these ingredients is one of the first steps towards making sense of this fascinating Japanese beverage.
Is Sake Just Rice Wine?
Not quite.
Wine comes from fruit that already contains fermentable sugar. During winemaking, yeast converts the natural sugars in grapes into alcohol.
Rice works differently. It contains starch rather than readily fermentable sugar. Therefore, sake production requires an additional step. Producers must first convert the starch into sugar before yeast can turn that sugar into alcohol.
This difference makes sake production particularly interesting. In fact, learning how rice, koji and yeast work together helps explain many of the styles you eventually encounter in the glass.
So, while “rice wine” may offer beginners a quick reference point, it does not accurately describe the production process.
What Are the Key Ingredients of Sake?
Despite the complexity of its production, sake begins with a few essential ingredients. Each one performs a specific role.
Rice: The Foundation of Sake
Rice provides the starch needed to make sake.
Producers may use special sake rice varieties. These grains can have characteristics that make them particularly suitable for sake production, including larger grains and a concentrated starchy centre.
However, producers do not simply cook the rice and ferment it.
First, they polish away some of the grain’s outer layers. This process helps producers access the starch-rich centre while reducing components in the outer portion that can influence the finished sake.
The degree of polishing can also play an important role in sake classification and style. Therefore, understanding rice preparation provides a useful foundation for anyone studying a formal sake course.
Water: More Important Than You Might Think
Water forms a large proportion of the finished sake. Consequently, its quality and composition matter greatly.
Producers use water at several stages of sake production. Moreover, differences in water composition can influence fermentation and the overall character of the final drink.
For example, harder and softer water can contribute to different production outcomes and styles.
It is easy to focus entirely on rice when first learning about sake. However, water plays an equally fascinating role in understanding why different sakes can have distinctive characteristics.
Koji: Turning Starch into Sugar
This is where sake production becomes especially interesting.
Yeast needs sugar to produce alcohol. However, rice contains starch. Therefore, producers need a way to convert that starch into fermentable sugar.
Enter koji mould, or Aspergillus oryzae.
Producers cultivate koji mould on a portion of steamed rice. The koji produces enzymes that break rice starch down into sugars. As a result, those sugars become available for yeast to ferment.
You can think of koji as an essential bridge between rice and alcohol.
This process is also one reason why simply calling sake “rice wine” misses an important part of the story. Grapes already contain fermentable sugars, whereas rice needs this conversion stage.
Yeast: Creating Alcohol and Aroma
Once sugars become available, yeast can get to work.
Yeast converts those sugars into alcohol during fermentation. At the same time, it contributes to the aromatic character of sake.
However, sake fermentation has another fascinating feature. The conversion of starch into sugar and the conversion of sugar into alcohol can occur alongside each other.
Therefore, sake production differs significantly from the basic fermentation process used for wine.
Understanding this relationship between rice, koji and yeast is fundamental to understanding how sake is made.
The Secret Sauce: Lactic Acid?
Lactic acid also plays an important role in sake production.
It helps create an environment that supports healthy fermentation by controlling unwanted microorganisms. Depending on the production method, the required acidity may develop naturally or producers may introduce lactic acid.
For beginners, however, the key idea is simple: acidity helps create suitable conditions for the yeast to carry out fermentation successfully.
The WSET Level 1 Award in Sake at Sonal Holland Academy offers beginners a structured introduction to this category. You will explore sake’s key ingredients, fundamental production methods, principal categories and grades, speciality styles, and essential storage and service principles.
The qualification is an excellent starting point for hospitality professionals, beverage students and enthusiasts who want to build credible sake knowledge. Click here to know more about our upcoming batch.
