The Secrets of Sake Kasu: Expert Guides on Everything from Flavor Types to Use and Storage Methods

Sake kasu, or sake lees, is produced during the sake brewing process. Traditionally, kasu was used in everyday cooking in Japanese homes, but in recent years, while disposal has become a problem due to decreasing demand, it is now becoming popular again due to its high nutritional value.

One person who loves sake kasu more than anyone else is Mari Shimura, a.k.a. Sake Kasuko. She is a certified nutritionist and is currently enrolled in the doctoral course of Niigata University's graduate school's sake studies program.

According to her, sake kasu is as diverse and enjoyable as sake! She talked to us about its use.

Sake Kasuko (Mari Shimura)
Registered dietitian. After graduating from the Department of Food and Nutrition, Graduate School of Agriculture, Tokyo University of Agriculture, she worked as a working adult before enrolling in the doctoral program of the Niigata University Graduate School of Sake Science. While at Tokyo University of Agriculture, she encountered sake kasu and was impressed by its taste and high nutritional value. Currently, while engaged in research on functional ingredients of sake kasu at Niigata University, she organizes sake kasu cafes and study groups with the hope of conveying the concept of “eating food that pleases both body and soul” through sake kasu.

Lees of delicious sake is delicious

Her first encounter with sake kasu was as an undergraduate student at Tokyo University of Agriculture. She loved sweets, especially whipped cream, but suffered from acne and other skin problems.

“When I wanted to eat without holding back, but didn't want to gain weight, a senior student at the university told me about sake kasu. I was attracted by the fact that it was creamy and rich, yet healthy. When I was a graduate student, I even used sake kasu amazake as my staple food because I had neither money nor time.”

She has eaten more than 100 kinds of sake kasu so far. Sake kasu is also known for its various healthy functions, but the most important reason for her love is that it is tasty.

“Sake kasu can be used for a variety of purposes, but I personally prefer to eat it as is. I like sake kasu that has a slight sweetness, a moderate sourness, and little bitterness.

It was the sake kasu of the Tatenokawa Sake Brewery in Yamagata Prefecture that led me to learn that the taste of it differs from brewery to brewery. I had always liked Tatenokawa's sake, but when I tasted it, I was shocked to find that it tasted completely different from the sake kasu I had been used to. Here is how I learned that the sake kasu of good sake tastes good.

Tatenokawa’s sake kasu is sold almost exclusively for food use, and the supply is so small that it cannot keep up with the demand. I buy sake kasu from various breweries, but have never heard of this from other breweries.”

Recommended usage by type

“Sake kasu has as much diversity as sake,” Sake Kasuko passionately states. First, according to her, there are four main types of forms.

“The form of sake kasu changes depending on the way the moromi mash is pressed, which in turn affects its flavor and usage.

The first is plate lees. It is pressed strongly in a machine such as the Yabuta method, so its flavor is often as rich as cheese. In addition to being added to stews and other rich dishes, this type of cheese is recommended for vegans.

The second is chopped lees. It is pressed without too much pressure, such as by fune (a traditional vertical pressure press) pressing, so it is looser than plate one. It retains the sweetness and sake-typical aroma, and is tasty even when eaten as is. This type is recommended to make amazake.

The third is paste lees. Since it is matured, many of them have a peculiar taste typical of sake kasu, and when added to cooking or baking, it gives richness and flavor.

The last one is the loose type. It is the lees of sake squeezed without pressure, such as fukuro or hanegi, so it is loose. Many of them are fruity or sweet, and are heated a little and added to dressings and other dishes. There is quite a bit of alcohol left in them, so those who are weak drinkers should be careful.”

Four Types of Sake Lees

The flavors also vary from fruity to rich and bitter. As for what is sold in supermarkets and what is sold directly by sake breweries, she said, “Sake kasu from supermarkets are delicious, but you can get the freshest ones if you buy them from a sake brewery."

Maturation and storage of sake kasu

Just as freshly opened sake may not have much flavor yet, freshly pressed sake kasu may not have much flavor either.

"Just like sake, sake kasu tastes sweeter and tastier when it is allowed to sit for a while. This is because the rice grains are digested by enzymes. It depends on the temperature, but if you leave it in a dark place at about 20 degrees Celsius for about a week, it will take on a lot of flavor."

Of the above four types, plate kasu is the best suited for aging.

"To taste, but it gets denser as it ages. Loose lees can also be aged, but depending on the product, water may come out and they may become crumbly. Sake kasu that has turned brown after aging is delicious when added to stewed dishes.”

The longest that Sake Kasuko has aged by herself so far is two and a half years, and the longest that she has purchased is 10 years. When she ages her own lees, she keeps it at room temperature in enameled jars, which are easier to store. The one shown to us at the interview had been aged for a year and a half, and had turned a dark brown color like miso.

"The great enemies of sake kasu storage are sunlight and oxygen, so try to keep it as oxygen-free as possible and keep it in a cool, dark place or some other place that is not exposed to light. I sometimes hear people say, 'The refrigerator fills up with sake kasu,' but it is okay to store it at room temperature. Freezing stops the aging process and preserves the flavor, so it is best to put it in the freezer when it has matured to a good taste.”

Sake Kasuko recently purchased a refrigerator for her sake kasu collection: she was concerned about the lack of space and the smell of other food in the refrigerator.

"Sake kasu can persist for a long time, but it can absorb odors and become unappetizing. Packaging for sale often has pores to release gas from sake kasu, so replace it with a double-layered Ziploc bag. Freezers are especially prone to transferring the smell, but covering the bag with aluminum foil over the top will keep oxygen from getting through.”

Points for storing sakekasu
・Store at room temperature.
・Seal in a ziplock or jar to prevent exposure to air.
・Store in a dark and cool place or in a light-shielded container to avoid exposure to sunlight.
・If you feel to keep the current flavor, put them in the freezer.
・Store in a cool, dark, and sun-shielded container or in a freezer to preserve the flavor.

Include sake kasu in your daily diet

Sake Kasuko is currently studying the ingredients of sake kasu at Niigata University's graduate school. While reminding us that “it's not something you can just eat and be healthy right away,” she gave us the details of the previous research.

“Sake lees has as much dietary fiber as avocado, and I often hear stories of improved bowel movements. It contains as much protein as steamed soybeans, which means that it has the highest level of protein among plant foods. In addition, according to experiments with mice, animal experiments using sake kasu powder and sake-kasu fermented products have reported a lowering of blood cholesterol and neutral fat, as well as an obesity-inhibiting effect (*). It is my own personal experience that it makes me less likely to gain weight.”

Although there are many aspects of the health effects that cannot be stated explicitly, it is possible to try to have a healthier diet by replacing your usual food with sake kasu.

“Sake kasu is a good substitute for cheese. Cheese is high in animal fat and contains a lot of salt, so if you are concerned about your health, replacing it with sake kasu is recommended. Cheese is also a fermented food, and in the case of cheese, the solid part is left and the whey, the liquid part, is discarded, so it has a lot in common with sake kasu in terms of making.

For those who want to avoid cheese for health reasons or those who cannot eat cheese due to their constitution, sake kasu is a good alternative. There are many vegans overseas, and I feel it could be promoted as a healthy, plant-based food.”

Just as Sake Kasuko, who loved whipped cream, was attracted to the rich and creamy sake kasu, people who like dairy products are likely to like sake kasu.

Reference:
・Toshiro Watanabe, 健康と美容に貢献する 「酒粕」 の成分 [Ingredients of “Sake Lees” that contribute to health and beauty]. (2012)
・Hisako Kubo, et al. "Sake lees extract improves hepatic lipid accumulation in high fat diet-fed mice." Lipids in Health and Disease 16.1 (2017)
・Kazumi Mochida, et al. ラットのコレステロール代謝改善効果を有する酒粕粉末の調製. [Preparation of sake kasu powder with the effect of improving cholesterol metabolism in rats.] Journal of the Japanese Society for Food Science and Technology 47.2 (2000)

Recommended way to eat for who are not familiar with sake kasu

Because sake kasu is rich in nutrients, Sake Kasuko says, “I want people to take it in a health-conscious way."

“For example, if you use it in baking, but make a cake with lots of sugar, it will not be associated with good health. Using sake kasu, with its natural sweetness and aroma, you can reduce the amount of sugar. Incidentally, there is also a good thing about adding it to baked goods: it makes them moist. Also, amazake made with sake kasu has a moderate sweetness, but we recommend using rice malt amazake instead of sugar to add sweetness.

Also, if you want to consume a large quantity, you can marinate the meat in a mixture of sake kasu and miso for a while before grilling. As I like to eat sake kasu, I feel it is a bit of a waste because I have to peel off the sake kasu before grilling the meat to prevent it from burning (laughs), but it makes the meat softer and more delicious.”

Finally, she gave us some advice for those who have sake kasu but don't know how to use it.

When you get sake kasu, spread it on aluminum foil and bake it in a toaster for now. Baked sake kasu is a quick and delicious way to eat kasu. When baked, it looks just like cheese, and I think it will make you realize the charm of sake kasu.

Sake kasu is hard to handle as it is, so when you use it for cooking, try to soften it a little by mixing it with water. If you can do that, it will be easier to use in various dishes.”

Listening to Sake Kasuko, who is brimming with love for sake kasu, it is clear that sake kasu is as diverse and full of unknown delicacies as sake itself. For sake breweries, sake kasu is a source of worry for disposal. Let's learn to use sake kasu, which is good for the sake brewery, good for the environment, and good for you!