Welcome to

Aya’s Culture Kitchen

We’re delighted to bring you the authentic taste of natto, Japan’s beloved traditional fermented soybean dish known by experts as a superfood.

About Us

Welcome to Aya’s Culture Kitchen!  We’re delighted to bring you the authentic taste of natto, Japan’s famous fermented soybean superfood.

Discover the amazing health benefits, unique flavor, and unmatched texture of our traditional, high-quality natto, made from organic soybeans, lovingly crafted fresh in the United States by our founder, Aya Abe. Explore our website to learn more about our story, our products, and the delicious recipes you can create with natto!

🙂 our Products

Welcome to our one-stop shop for delicious and nutritious Japanese fermented natto, a traditional Japanese food made from fermented soybeans.  Most natto sold in the US is made in Japan and frozen for the long journey.  Alas, freezing natto takes away from its flavor.  Here at Aya’s Culture Kitchen we make natto fresh, with organic soybeans, right here in Boston, and don’t freeze it.  Try it to discover the authentic original taste of natto.  You can either pick it up at our farmstand, or have us ship it to you.  See the product listings below for details and options.

What is Natto?

Natto is a unique and traditional Japanese food made from fermented soybeans. Other than the culture itself, soybeans are the only ingredient, making natto naturally vegan and additive-free.  Natto is packed with nutrients that are beneficial for your health. In Japan, it has been a popular food choice for centuries, often enjoyed at breakfast, as a snack, or as part of various dishes.  Many Japanese eat it every day.

The fermentation process for natto involves the use of beneficial bacteria, similar to those found in yogurt. These bacteria transform the soybeans into natto, giving it a subtle nutty taste and aroma.

Natto offers numerous health benefits, including promoting a healthy digestive system, supporting heart health, and contributing to strong bones. By trying natto, you’ll not only experience a unique aspect of Japanese cuisine but also give your body a nutritional boost. So, go ahead and explore the world of natto – you might just discover your new favorite food!

Our natto has a mild flavor.  Many people enjoy mixing it with condiments such as soy sauce, mirin, sesame salad dressing, Japanese umeboshi pickled plums, and even bananas.  Experiment and discover your own preferred way to eat natto.

History of Natto

Natto has a long and fascinating history that dates back over a thousand years in Japan. As a traditional food, it is deeply rooted in Japanese culture, enjoyed for its unique taste and health benefits.

There are a few legends about how natto came to be. One popular story suggests that it was accidentally discovered by a group of Japanese samurai warriors. After boiling soybeans for their meal, the samurai were suddenly called into battle, leaving their beans behind. When they returned days later, they found that the soybeans had fermented, creating the first-ever batch of natto.

The fermentation process for natto utilizes a specific type of bacteria called Bacillus subtilis. In ancient times, people likely stumbled upon this bacteria because it is naturally present in straw, which was used to store and transport soybeans. The interaction between the bacteria and the soybeans, combined with water and heat, resulted in the creation of natto, with its distinctive taste, texture, and aroma.

By learning about the history of natto, you can gain a deeper appreciation for this ancient Japanese food and its enduring cultural significance. As you explore the world of natto, you’re not only enjoying delicious and nutritious food but also taking part in a culinary tradition that has been cherished for over a millennium.

What are Natto's health benefits?


Natto is fermented with Bacillus subtilis natto, a type of probiotic bacteria that supports gastrointestinal health. Probiotics help maintain a healthy balance of good bacteria in the gut, which can improve digestion, boost the immune system, and contribute to overall well-being.

Cardiovascular health

Natto contains an enzyme called nattokinase, which has been found to support cardiovascular health. Nattokinase helps break down blood clots and may lower blood pressure, reducing the risk of heart disease and stroke.

Bone health

Natto is a rich source of vitamin K2, which plays a crucial role in bone health. Vitamin K2 helps the body use calcium effectively, promoting strong bones and reducing the risk of osteoporosis.

High in nutrients

Natto is packed with essential nutrients including protein, dietary fiber, vitamins, and minerals. It contains vitamins B2, B6, and E, as well as minerals like calcium, iron, magnesium, and potassium.

Soy isoflavones

Soybeans, the main ingredient of natto, are rich in isoflavones. These plant compounds have been linked to various health benefits, such as reducing the risk of certain types of cancer, improving menopausal symptoms, and supporting heart health.

Weight management

The dietary fiber in natto can help with weight management by promoting a feeling of fullness and aiding in digestion. This may help with appetite control and prevent overeating.





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Blog & Recipes

Here, you can find creative and delicious ways to enjoy natto, from traditional Japanese dishes to innovative fusion recipes


塩麹とは? 2010年に爆発的な塩麹ブームが起こったのを覚えていますか?「魔法の調味料」として知られる塩麹は、お水・米麹・塩から作られています。 塩麹が食材を美味しくする理由 塩麹には「プロテアーゼ」という酵素が入っています。プロテアーゼはタンパク質を分解する働きがあるので、お肉やお魚を塩麹で漬けると柔らかくなるというわけなのです。 タンパク質は、アミノ酸でできているので、分解されると旨みの成分でもあるアミノ酸が増え、食材の旨みが増します。 塩麹には塩が含まれているので、料理に塩見を加えるとともに、安全に長期保存することができます。 余談ですが、お料理のレシピに塩が入っている場合、塩の2倍の量の塩麹で代用することができます。食材に旨みと深みがプラスされるので、お試しあれ!   塩麹、結局何日漬けるのが正解なの? 塩麹を使ったレシピを見ていると、「30分から3日漬け置きする」のように、かなり幅広い漬け置き時間が書かれていることがあります。一体、どれくらいの間漬けるのがベストなの?   そんな疑問にお答えするべく、ちょっとした実験をおこなってみました。   鳥の胸肉を準備し、170gずつ測り、タイミングをずらして大さじ1の塩麹に漬けました。 72時間(3日間)

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ソウルの帰りに関西空港で降り、三重の「発酵ツアー」に参加しました。 SNSでお友達になった三重在住の方に発酵関係のイベントがあるかどうか訪ねたところ、ツアーを企画してくださったのです。 ツアー初日は、お味噌やお醤油の蔵を3箇所巡りました。 最初に訪れたのは、東海醸造さん。 東海醸造さんは、豆味噌とたまりを作っています。 実は私は、豆味噌にはこれまでの人生でほとんど馴染みがありませんでした。お味噌って、地域によって違った種類が普及していますよね。 私は神奈川県出身なのですが、関東地方は辛口の米味噌が主流となっているらしく、祖母が子供の頃に作ってくれたお味噌汁も、塩気の強いお味噌汁でした。 蔵に入ると、大豆が熟成された良い香りがしました。 豆味噌は、豆を蒸すところから始まるのだそうです。実は、納豆も、大豆を煮るのではなく蒸して作ります。蒸すことにより、大豆本来の旨みが損なわれずに済みます。 5年ものの豆味噌を試食させていただきました。 塩辛くて旨みが強く、お酒のアテにぴったりな味です。 それから、現代ではとても珍しい「生引きたまり」も味見させていただきました。 木桶の下の方についていく栓を開けると、濃厚なたまりが出てきます。 実は、このツアーに参加するまで、「お醤油」と「たまり」の明確な違いをわかっていませんでした。が、ツアーに参加していくつか学んだことがあるので、ここに書き留めておきますね。 原料の違い

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韓国・ソウルで発酵の旅その② 友人のレストランNattodoを訪ねてみた

韓国滞在二日目は、納豆仲間のジェさんが納豆の定食屋さんを今年2月にオープンしたと伺ったので、行ってきました! 閑静な住宅街の中にあるジェさんのお店は、絵本に出てきそうな可愛さ。良い感じの音楽も流れていて、超おしゃれです。主に、女性やカップルのお客さんが多いのだとか。 ランチ時だったので、ジェさんおすすめの「春の山菜乗せそば」を選択。丁寧に手作りされている納豆と、こだわりの食材を使ったお蕎麦です。山菜は、季節のお野菜をジェさん自ら市場に買い出しに行かれているとのことで、とても新鮮でした。 お酢で味付けされており、ツルツルとあっという間に平らげてしまいました。納豆もふっくら大粒で、本当に美味しい!それにしても、お酢と納豆の組み合わせって合うのですね。新たな発見でした。 夜はバーにもなるようなので、ぜひソウルに行かれる時は訪れてみてください。   【お店の情報】 3-9 Hyochangwon-ro 55-gil Yongsan-gu, Seoul Instagram: nottodo_natto

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Frequently Asked Questions

Our natto has a unique taste that is savory, umami-rich, and mildly nutty.  It is well-loved in Japan and appreciated for its distinctiveness and health benefits.  Many Japanese eat it every day for breakfast.

Yes, properly made fermented foods are considered very important for gut health. They contain probiotics, which are beneficial bacteria that help maintain a healthy balance in your digestive system. Consuming fermented foods have been found to improve digestion, boost the immune system, and contribute to overall well-being.

The effects of probiotics are enhanced when they are consumed together with prebiotics. Prebiotics are a type of non-digestible fiber found in certain fruits, vegetables, and whole grains that act as food for the probiotics. By providing the probiotics with the nutrients they need to thrive, prebiotics help the probiotics work more effectively and promote a healthier gut environment. Combining probiotics and prebiotics in your diet can lead to improved digestion and overall well-being.  One of the unique characteristics of natto is its combination of probiotics and prebiotics in a single food!

While natto can endure room temperature for days at a time, its fermentation will speed up, resulting in a more pungent flavor.  To prevent over-fermentation, natto should be stored in the refrigerator, preferably at temperatures between 35°F and 40°F (2°C and 4°C). Keeping it in its original packaging or a sealed container will help maintain its freshness and prevent the absorption of other odors in the fridge.  After a month or more, you may notice natto becomes “gritty” or sandy.  This is due to the natural formation of crystals.  While these do not pose a health hazard, they are unpalatable, and such natto should be discarded.

Yes, you can freeze natto to extend its shelf life. To freeze natto, place it in an airtight container or a resealable plastic bag, making sure to remove air as much air as possible. Frozen natto can last for several months, but it’s best to consume it within 3-4 months for optimal quality. When you’re ready to eat the natto, thaw it in the refrigerator for a few hours or overnight before serving.

Many natto afficionados will tell you that natto tastes better and has more active bacteria when it has never been frozen. Freezing may slightly alter the texture and taste, so for the best natto experience, it’s recommended to consume it fresh whenever possible.

After fermentating our natto, Aya’s Culture Kitchen refrigerates natto for a minimum of one day.  During this initial refrigeration period, important proteins and enzymes are formed, which help give natto its unique taste.  Brand new natto that has been refrigerated for only one day has the mildest taste.  While some people prefer this taste, others say that natto tastes best after about two weeks of refrigeration from the production date, as its natural flavors deepen.  We encourage you to experiment with our natto to decide the aging period you like best.

There are in fact some huge sustainability element to our business. Almost all natto in the US until now has been frozen (using energy) and shipped 6,000 miles. In addition, a big portion of the dried soybeans used for making natto in Japan are actually imported from the U.S. So, for starters we are eliminating that. As to the containers themselves, while we are not permitted to bring outside containers back into our kitchen as we cannot allow any possibility of contamination at all, our customers are telling us they reuse these containers for food storage. That said, if you have any other ideas, please share them with us!