Discover Koji, the Secret Ingredient Behind Umami, with A Koji-Based Drink Tasting & Lunch

Learn About Koji, the Foundation of Japanese Food Culture

Koji is a mold and fungus that is used as an ingredient for soy sauce, miso, sake, and other essential condiments and seasonings in Japanese cuisine. Since ancient times, its fermentation ability has been passed down as the foundation of Japanese food culture. It is also the secret to umami, as the enzymes in koji bring out the umami of food and create a rich flavor.

In 2006, koji was certified as the national fungus of Japan

One brand devoted to spreading the appeal of koji is Nagaya, which develops amazake and koji seasonings. According to CEO and representative Nagisa Nagaya, her desire to serve delicious and healthy meals for her own family drew her attention to koji — the foundation of Japan's ancient fermentation culture — and prompted her to start Nagaya.

Her search for ways to create koji products led to a chance encounter with a soy sauce manufacturer with over 100 years of history in Ishikawa Prefecture, where Japanese fermentation culture is deeply rooted. Since then, Nagaya and the Ishikawa-based manufacturer have jointly developed and sold fermented products suited to modern lifestyles.

One of the instructors for this experience is Nagaya CEO and representative Nagisa Nagaya

Taste Different Types of Amazake to Appreciate the Flavor of Koji and Rice

This experience begins with an explanation on the basics of koji as you sample three different kinds of amazake, a traditional fermented drink made with rice koji. Though some types of amazake contain low amounts of alcohol, the amazake from Nagaya that you will taste are all non-alcoholic. With amazake’s gentle taste, even children as young as two years old can enjoy it, making it a suitable drink for families.

For this experience, you will sample non-alcoholic amazake

The three different types of amazake, all differing in color and flavor, are created by changing the blend of rice and mold. They must also be finely managed — for instance, by fine-tuning the temperature and fermentation time depending on the season. Nagaya's amazake all use elegantly designed packaging and are named after their respective colors: Shiro (white), Tanko (pale yellow), and Kuro (black). Take your time as you feel the individual differences in taste and texture on your tongue.

Three types of amazake differing in color and taste

Nagaya’s amazake are all made with carefully selected rice and rice koji from Ishikawa Prefecture, as well as the techniques of fermentation experts at a long-standing soy sauce shop — resulting in amazake that the shop can uniquely call its own. The Shiro variant uses the koji Aspergillus oryzae, which is known for its high levels of enzyme secretion, resulting in a refined sweetness and rich taste. Tanko has an enjoyably refreshing scent reminiscent of citrus, while Kuro derives its distinctive color from being made with brown rice instead of white rice.

Even in a small cup or glass, each type of amazake has a distinctive taste

A Koji Seasoning That Can be Easily Added to Your Household Pantry

After sampling different types of amazake, you will make koji seasoning. “Although koji seasonings are Japanese, they can be easily added to Western cuisine as well,” explains Ms. Nagaya. In this experience, your instructor will explain how to make soy sauce koji by adding koji to soy sauce, then letting the mixture ferment.

Soy sauce koji is very easy to make. Shio koji, which uses salt and water instead of soy sauce, is one of the best-known koji seasonings

Combining the flavor of soy sauce with the natural sweetness of koji, soy sauce koji is Ms. Nagaya’s recommended type of koji seasoning, as you can create it anywhere so long as you have dry koji and soy sauce. It is simple but versatile — you can marinate meat in soy sauce koji, then grill it with vegetables to create a healthy dish full of umami. Those who like Japanese food can also add this seasoning to tofu, natto, or rice. Take what you learned from this experience home and try making koji seasoning on your own.

The appeal of making your own koji seasoning is looking forward to the changes as the koji ferments in two to three weeks

Make Onigiri and Indulge in Koji-Based Dishes and Desserts

The last activity of this experience is making Japan’s iconic triangular onigiri using flavorful rice infused with koji. You will then enjoy your onigiri with your lunch, which makes use of koji for all dishes. You can choose between a Japanese or a Western main dish. Either way, the onigiri that you made will complement your meal. The recipes for the dishes, such as the shio (salt) koji-based hearty seasonal soup that accompanies Western main dishes, can all be easily replicated at home.

Onigiri that you made yourself has a particular taste to it

Your delightful meal will end with a special Nagaya dessert made with carefully selected ingredients and koji. While enjoying the food, feel free to let your instructor know your thoughts on this experience and koji. Finally, to conclude this experience, you will receive a set of amazake and koji seasoning in a bamboo basket, as well as recipes for easily incorporating koji into your meals.

The Japanese-style lunch includes umami-rich koji-infused rice balls, miso soup, and seasonal ingredients

A Life with Koji Leads to a Healthier Lifestyle

This experience is a valuable opportunity to delve into the rich flavor and secrets to good health that Japanese food is known for. Learning about koji and incorporating it into your life will surely enhance the flavor and healthiness of your daily meals, as well as deepen your understanding of Japanese food culture. Join Nagaya on this special encounter with koji to understand why it is so important to Japanese cuisine.

Koji is an important ingredient for better understanding Japanese food culture and traditions