Japanese Food Guides

For centuries, Japanese chefs have relied on one powerful ingredient to create deep flavor, natural sweetness, and incredible umami: koji. Although many people outside Japan are only beginning to discover it, koji has long been an essential part of traditional Japanese cuisine and fermentation culture. Today, professional chefs around the world are also embracing koji for its ability to transform ingredients and elevate cooking naturally. So why do Japanese chefs use koji so often? What Is Koji? Koji (麹) is made by fermenting steamed rice, barley, or soybeans with a beneficial mold called Aspergillus oryzae. During fermentation, koji produces natural enzymes that break down proteins and starches into amino acids and sugars. This process creates: Rich umami flavor Natural sweetness Greater depth and complexity Improved texture Koji is the foundation of many traditional Japanese foods, including: In Japan, koji is often called The heart of Japanese fermentation. Miso　View Collections Soy sauce　View Collections Sake Mirin Amazake Shio Koji　View Products Without koji, Japanese cuisine as we know it would not exist. Add Koji Paste to Cart Add Semi-Dried Shio Rice Koji to Cart Koji product 1. Koji Creates Natural Umami One of the main reasons Japanese chefs use koji is that it naturally increases umami. The enzymes in koji release amino acids such as glutamate, which are responsible for savory flavor. Instead of relying on artificial flavor enhancers, chefs can use koji to create a deep, satisfying taste naturally. This is why many Japanese dishes feel rich and flavorful even when they use simple ingredients. 2. Koji Makes Meat and Fish More Tender Koji is also widely used as a marinade. When meat or fish is marinated with shio koji or koji-based seasonings, the enzymes help break down proteins gently. As a result: Meat becomes more tender Fish develops a richer flavor Clean-label products Ingredients stay juicy during cooking Many chefs compare koji marination to natural aging techniques because it improves texture and depth without overpowering the original ingredient. Today, "koji marinade" has become increasingly popular among chefs worldwide. 3. Koji Enhances Ingredients Naturally Japanese cuisine often focuses on bringing out the natural qualities of ingredients rather than covering them with strong seasoning. Koji helps chefs achieve this balance beautifully. Instead of adding heavy sauces, koji enhances: Sweetness Aroma Umami Complexity This creates elegant and balanced flavors that are central to Japanese cooking philosophy. 4. Koji Supports Fermentation Culture Fermentation has always played an important role in Japanese food culture. Japanese chefs use koji not only for flavor but also as part of traditional food preservation and fermentation techniques developed over centuries. Koji allows chefs to create: Miso　View Collections Soy sauce　View Collections Sake Mirin Amazake Shio Koji　View Products These fermented foods contribute depth, character, and tradition to Japanese cuisine. 5. Modern Chefs Are Rediscovering Koji Today, chefs around the world are experimenting with koji in new and creative ways. Koji is now used in: Steak marinades Kankoji SteakView Recipe Vegan cooking Koji NattoView Product Plant-based cheese Sauces and dressings: Fermented Tomato SauceView Recipe Desserts Lemon Koji SyrupView Recipe Fine dining fermentation Many modern chefs appreciate koji because it offers: Clean-label flavor enhancement Natural fermentation Reduced need for additives Sustainable cooking possibilities As interest in fermented foods and gut-friendly eating grows globally, koji continues to gain attention far beyond Japan. A Traditional Ingredient for Modern Cooking Koji has been quietly shaping Japanese cuisine for over 1,000 years. What makes it special is not only its history but also its ability to naturally improve flavor, texture, and depth in cooking. From traditional Japanese kitchens to modern restaurants worldwide, chefs continue to use koji because it transforms simple ingredients into something extraordinary. At Yamasan, we are proud to share authentic Japanese fermentation culture from Kyoto, Japan, with customers around the world. Discover the rich world of koji and experience the natural power of Japanese fermentation in your own kitchen.

In Japan, few traditional foods are as iconic — or as nutritionally impressive — as Natto. Made by fermenting soybeans with Bacillus subtilis (natto bacteria), natto has been enjoyed for centuries as a daily source of nourishment and wellness. Its sticky texture and rich umami flavor may surprise first-time eaters, but behind that distinctive character is a remarkable combination of plant protein, vitamins, minerals, and unique fermented compounds that support everyday health. What Makes Natto So Special? Unlike ordinary soybeans, natto gains additional nutrients and enzymes during the fermentation process. This means you get both the natural goodness of soybeans and the benefits created by fermentation. A single pack of natto (about 45g) contains: High-quality plant protein Dietary fiber Vitamins B2, B6, E, and K Calcium, iron, magnesium, and potassium Natto-specific compounds such as nattokinase and vitamin K2 It’s a small food packed with an impressive nutritional profile. Rich in High-Quality Plant Protein Natto contains about 7.4g of protein per pack, comparable to roughly 54g of beef chuck roast. Protein is one of the body’s essential nutrients. It helps build muscles, skin, hair, organs, hormones, and antibodies. Because natto is made from soybeans, it provides a high-quality plant-based protein source that fits naturally into balanced diets. For people looking for more plant-forward meals, natto is an easy and satisfying option. A Great Source of Dietary Fiber Modern diets often lack enough fiber, but natto naturally contains both: Soluble fiber — supports fullness and digestive balance Insoluble fiber — helps maintain healthy digestion and gut movement One pack contains about 3g of dietary fiber, roughly comparable to several small carrots. This combination makes natto especially popular among people interested in gut health and everyday wellness. Vitamin B2: A Key Benefit of Fermentation One of natto’s standout nutrients is Vitamin B2 (riboflavin). Soybeans themselves contain relatively little B2, but fermentation dramatically increases it. Vitamin B2 helps the body convert carbohydrates, proteins, and fats into energy and supports healthy skin, hair, and nails. This is one reason fermented foods are so valued in traditional Japanese food culture. Vitamins That Support Everyday Wellness Vitamin B6 Vitamin B6 plays an important role in enzyme function, nervous system health, and red blood cell production. It also supports healthy skin and daily vitality. Vitamin E Known for its antioxidant properties, Vitamin E helps protect cells and supports healthy circulation. Vitamin K Natto is especially famous for its high Vitamin K content — particularly Vitamin K2, which is produced during fermentation. Vitamin K helps support normal blood clotting and healthy bones by helping the body utilize calcium properly. Important Minerals in Natto Natto also provides a variety of essential minerals: With just: Calcium— supports bones and teeth Iron— helps transport oxygen throughout the body Magnesium— involved in hundreds of enzyme reactions Potassium— helps balance sodium levels in the body Even in small servings, natto offers a surprisingly broad range of nutrients. Unique Compounds Found Only in Natto Nattokinase One of natto’s most talked-about compounds is nattokinase, an enzyme created during fermentation. It does not exist in plain soybeans. Nattokinase is widely known in Japan as a component that supports healthy circulation and overall wellness. Soy Isoflavones Soy isoflavones resemble the hormone estrogen in structure and are often associated with beauty and wellness support, especially for women. Lecithin Lecithin is a phospholipid connected to brain and nerve function and is often associated with memory and cognitive health. Polyamines Polyamines are compounds involved in cellular activity and healthy aging, making natto a food often associated with long-term vitality. The Power of Soybeans + Fermentation What makes natto truly fascinating is how fermentation transforms an already nutritious ingredient into something even more beneficial. Soybeans already contain protein, minerals, and beneficial plant compounds. But when fermented into natto, they gain additional nutrients like Vitamin K2 and nattokinase — nutrients not naturally present in soybeans alone. This combination of: Traditional Japanese fermentation Plant-based nutrition Convenient everyday eating is why natto continues to be loved across generations in Japan. A Simple Traditional Food with Modern Appeal As more people around the world explore fermented foods and plant-based nutrition, natto is gaining attention far beyond Japan. Whether enjoyed over rice, mixed into bowls, paired with noodles, or incorporated into modern recipes, natto is one of the easiest ways to add traditional Japanese wellness foods into everyday life. Sticky, flavorful, and incredibly nutrient-dense — natto truly is one of Japan’s hidden superfoods. Explore Our Natto Collection Discover traditional Japanese natto products crafted for everyday wellness, nutrition, and authentic flavor. Dried Natto Natto Fermented Soybean Powder Natto Furikake Seasoning Explore All Natto Products

Discover the essence of Japanese superfoods with Yamasan Kyoto Uji. Our selection includes nutrient-rich staples like natto, koji, and miso, each offering unique flavors and versatility in the kitchen. Explore our Healthy Choices collection to find these traditional foods and incorporate them into your daily cooking. 🌿 Natto: A Fermented Tradition Natto, made from fermented soybeans, is renowned for its distinctive texture and long history in Japanese cuisine. It's traditionally enjoyed over rice or mixed into rice bowls, and offers a good source of plant-based protein and fiber. Our Natto Fermented Soybean products offer a convenient way to enjoy this traditional food at home. Explore Our Natto Series 🍶 Koji: The Fermentation Catalyst Koji, a fermentation starter made from rice inoculated with Aspergillus oryzae, is fundamental in producing various Japanese condiments, including miso, soy sauce, and shio koji. It's the foundation of umami flavor in traditional Japanese cooking. Incorporate koji-based products into your meals to enhance flavor and depth. Explore Our Koji Series 🍲 Miso: The Umami-Rich Paste Miso, a fermented soybean paste, is a staple in Japanese cuisine known for its savory, umami-rich flavor. It has been a cornerstone of Japanese home cooking for centuries. Try our full and varied range of both Miso Pastes and Miso Powders to add depth to your soups, marinades, and sauces. Explore Our Miso Collection 🛒 Explore Our Healthy Choices At Yamasan Kyoto Uji, we're committed to offering products that align with a health-conscious lifestyle. Our Healthy Choices collection features vegan-friendly, non-GMO, and additive-free options, allowing you to enjoy authentic Japanese flavors while supporting your well-being. View Healthy Choices Collection Embrace the tradition and rich flavors of Japanese superfoods with Yamasan Kyoto Uji. Visit our online store to discover these and other wholesome products crafted with care and authenticity.