Amazake: A Japanese Super Drink

Japanese foods produced by fermentation, or hakko, have come to be well-known worldwide, from shoyu to miso, sake to mirin. But one you might not have heard of is a traditional fermented rice beverage called amazake.

Also known as koji amazake, this drink is naturally sweet and comfortingly creamy, a soft white in color and almost porridge-like in texture. In a nod to its origins in sake brewing, the name literally means “sweet sake,” but amazake made from rice koji contains no alcohol, making it suitable for everyone to enjoy. Whether served hot or cold, its sweet taste promises delicious replenishment.

That sweetness comes from the magical world of fermentation. As such, amazake’s signature flavor, part of everyday life for centuries, reflects a microcosm of Japanese culinary history.

Amazake is often consumed in Japan during special occasions, especially on New Year’s Day, when it is served to worshippers at shrines, and during Hinamatsuri, the Girls’ Festival, as a symbol of purification. There are even amazake festivals at shrines all over Japan.

So to find out what’s brewing in the world of amazake, Team Musubi visited Sennen-Koujiya, an amazake cafe nestled in Tokyo’s fashionable Azabujuban neighborhood. Sennen-Koujiya is run by one of Japan’s most famous sake breweries, Hakkaisan, a renowned sake brewery from Niigata Prefecture, offers a wide variety of amazake. We were fascinated by the selection, which includes both classic plain amazake and a variety of innovative flavors.

Join us in our exploration of the fascinating world of amazake, starting with its unique characteristics and rich history and moving on to our tasting experience at Sennen-Koujiya. Let’s dive together into this magical world.

Koji amazake is a cup of delicious simplicity. It’s made from just three ingredients: rice, rice koji, and water. This combination results in koji fermentation, which creates layers of umami and sweetness, similar to the flavors found in miso, soy sauce, and sake.

Not only is amazake sweet but it is also packed with nutrients. Amazake soothes when you’re sick or tired, almost like chicken soup or an energy drink. Moreover, since it’s easy to digest and typically alcohol-free, anyone can partake, from toddlers to the elderly.

It may even have a positive effect on physical beauty. The B group vitamins contained in amazake help to improve metabolism of carbohydrates, lipids, and proteins, and also promote healthy skin and hair. 

Since its birth, amazake has been an essential part of Japanese fermented foods and has had several jumps in popularity. In 2015, for example, it gained immense popularity alongside a boom in at-home fermentation. Numerous brands of amazake have been sold in supermarkets and convenience stores across the country since.

Recently, amazake has begun to spread abroad and be used in creative new ways, similarly to how matcha has been adopted both internationally and at home in both drinks and desserts.

There are said to be over 1200 amazake products made by approximately 600 amazake producers: sake breweries, miso producers, soy sauce makers, and more.

It is said that miso and soy sauce brewers tend to make a slightly thicker and creamier amazake that retains small pieces of rice grains. Sake brewers, on the other hand, are said to make a smooth and clear amazake. Despite this difference in texture, both types share the same natural sweetness.

Though typically non-alcoholic, slightly alcoholic amazake does also exist. This variety is called “sake kasu amazake” and is made by mixing water and sugar with sake kasu, or sake lees, a rice mash that is a by-product of sake production. At the end of the sake brewing process, rice mash is pressed to separate liquid from rice, leaving behind pure sake and sake lees. Sake lees have the aroma of sake but contain about 6 to 8 percent alcohol.

Unlike sake kasu amazake, which has added sugar, koji amazake (which contains no alcohol) is naturally sweet without added sugar.

Extra sugar isn’t needed in koji amazake because the way it’s brewed creates a natural sweetness brought about by the rice’s saccharification with rice koji.

So if you want to be absolutely sure you’re getting completely non-alcoholic amazake, it’s a good idea to specify you want alcohol-free “koji amazake” when you shop in a store or order in a cafe.

No, that is not a typo. Amasake with an S instead of a Z: this is the specialty of world-famous sake brewery Hakkaisan, which makes four types of amasake and has a cafe in central Tokyo’s Azabujuban, nestled between Roppongi and Tokyo Tower. Team Musubi visited the shop, Sennen-Koujiya, to learn how to prepare amazake for drinking and cooking.

So what is special about Hakkaisan’s signature “Amasake” that gives it its own particular spelling? We spoke to Tomomi Uemura, head of Hakkaisan PR, who explained, “The name symbolizes the clear taste of our Amasake by intentionally dropping the voiced ‘za’ sound.” She means the consonant sound change that often occurs in Japanese compound words. The result is that, linguistically, Hakkaisan is putting the “sake” back in amazake. “Also,” Uemura added, “We use koji made with techniques refined through sake brewing, giving it a clean and elegant flavor, much like sake.”

Sennen-Koujiya offers not only a cup of classic, plain Amasake but also a variety of innovative Amasake blended with matcha, soy milk, sake lees, Niigata strawberries, Japanese spinach, and more. In the winter season, they also have a special menu including winter Amasake soup with either lotus root, burdock root, or sake lees chowder.

Arai Miki, a store manager, said, “We have many female customers, from their twenties to their seventies, who buy our Amasake drinks. Their number one choice is plain. The next is matcha.”

Their plain Amasake is also sold in supermarkets and convenience stores throughout the country. What makes this classic flavor so popular with customers?

The secret lies in the koji mold HJ1 yeast that Amasake contains. Uemura explained, “Our Amasake was the first in Japan to be approved [by the Ministry of Health, Labour and Welfare] in the category of ‘Foods with Function Claims,’ based on the scientific evidence. We spent seven years researching HJ1 and its effects on health. As a result, we found that our Amasake has over 350 nutrients with health effects, such as helping maintain skin moisture and improving bowel movements by regulating the intestinal environment. So we are able to sell our Amasake with such a label."

Amazake is well known as a natural health booster due to its abundance of nutrients. It is said to be good for improving immunity, the intestinal microbiome, and skin health. However, unlike other fermented foods such as yogurt and cheese, amazake's health benefits have only recently been scientifically studied and recognized.

Besides the health benefits, taste and texture must be another reason for the popularity of Hakkaisan’s Amasake. What is the secret to its taste? Uemura told us its deliciousness is thanks to the rice they use: “We use 60 percent polished rice to manufacture Amasake—the same as when producing sake. The polishing of 40 percent of the rice’s outer layer, which contains protein and fat, further enhances the sweetness of the rice and makes the flavor richer.”

That’s not the only thing mellowing the flavor. The water used by Hakkaisan’s Amasake factory comes from the Mt. Hakkaisan range. The company’s—and the Mt. Hakkaisan’s—location, Minami Uonuma, is a treasure trove of nature: mild water, forests, and climate, which all help to grow delicious rice.

Uemura added, “In making Amasake we make sure to use the hand-crafted method of sake brewing we have developed for years. That’s another key to our clear flavor note.”

Hakkaisan’s koji Amasake production process is simply an automated version of what the locals have long done by hand.

1. Rice Milling

Using a rice milling machine, rice is polished down to isolate just the starch in each grain.

2. Washing/Soaking

The 60% polished rice is then washed and soaked in plenty of water to begin introducing moisture into the grain and preparing the rice for steaming.

3. Steaming

The water-saturated rice is slowly steamed.

4. Cooling

The steamed rice is allowed to cool well.

5. Inoculation

Once cooled to the right temperature, the rice is inoculated by sprinkling it with koji mold spores.

6. Koji Cultivation

Steamed rice is inoculated with koji mold and left to rest in a koji-making machine for about 48 hours to produce koji.

7. Final Processing

The koji is then stored with water in a tank kept at 50–60 degrees until enzymes in the koji break off the starch in the rice to sugar. Koji amasake is completed overnight.

In Hakkaisan's sake koji-making process, the rice is stirred by hand, wrapped in a blanket, and allowed to ferment slowly. This process is faithfully reproduced by a machine in the factory, using the same ingredients as before.

The start of the process is the same as koji Amasake production steps 1–5. But instead of moving on to koji cultivation, the process veers off, following almost the same steps as those involved in sake production.

After steps 1–5, the process continues:

6. Final Processing
Sake lees, water, and sugar are combined in a tank, heated, and fermented with the help of yeast and lactic acid bacteria. Sake kasu Amasake has a rich sake aroma. When heated, the aroma of alcohol intensifies and it takes on a unique, slightly tart, rich, and deep flavor.

Finally, we got to discover the magic of amazake for ourselves with a taste test. We tried two of Sennen-Koujiya’s popular Amasake drinks: iced matcha Amasake and hot sake kasu Amasake.

The iced matcha Amasake far exceeded my expectations. It had a mellow sweetness, different from sugar, that complemented the subtly astringent taste of matcha. For me, an amazake lover who drinks a thicker type of homemade amazake almost everyday, it was a great discovery—their clear Amasake had a refreshing taste and paired perfectly with matcha. Next was the cup of hot sake kasu Amasake, which warmed my numb body from the cold and filled my nose with the pleasant aroma of sake. It was an interesting experience to discover how amazake can bring out the flavors and scents of other ingredients.

The store manager, Arai, next told us about ways to use koji amasake in cooking as either a seasoning or as a sugar. One of her recommendations is to blend koji amasake with tomato juice along with a teaspoon of lemon juice to make a delicious, instant tomato soup. She also recommends mixing amasake with sparkling water. It is a surprisingly good combination.

Amazake also makes a good salad dressing: just mix it with salt—or, even better, salted rice malt—pepper, vinegar, and olive oil. Japanese cuisine is high in sugar, so using amazake as a sugar substitute may be better for one’s diet.

Uemura said that maintaining a consistent temperature is essential to preserving the flavor and quality of Hakkaisan's amasake, making it difficult to export overseas. The best way to taste it is to actually come to Japan and try it. You will also find other fermented foods from Uonuma and, of course, their sake, so it might very well be worth the trip! Perhaps you, like me, will become fascinated by the magic of amazake and Japan’s unique fermented food culture.