Tamba Dainagon azuki: characteristics and product information
| Origin | Oji district, Kasuga, Tamba City, Hyogo, Japan |
|---|---|
| Crop | Tamba Dainagon azuki (dried beans) |
| Characteristics | Large, deep-red beans, known for holding their shape when cooked. Every bean offered for sale is sorted by hand. |
| Flavour | Rich bean flavour and gentle sweetness. We find a particular depth to their taste. |
| Suggested dishes | Zenzai (sweet azuki soup), chunky bean paste, dorayaki and manju sweets |
| Sowing | Usually mid- to late July, occasionally early August |
| Harvest | Usually around mid-October to late November, varying with weather and sowing date |
| Harvest and processing | Ripe pods are hand-picked over several rounds and slowly dried on straw mats. After shelling, every bean is individually sorted by hand. |
| Growing approach | Grown without synthetic pesticides or chemical fertilisers. We do not hold Organic JAS certification. |
| Sales and purchase enquiries | Availability depends on harvest quantities and sorting results. Enquiries for next season are welcome. |
Flavour descriptions include our own tasting impressions. Harvest dates and availability vary from year to year.
Purchase and availability enquiries
For home cooking, confectionery businesses, restaurants or shops, tell us your preferred quantities and timing. We confirm the quantity and quality after drying and sorting before explaining what we can offer.
Registering interest is free and carries no obligation to buy. It does not reserve produce. An order is confirmed only after you have checked and agreed to quantities, prices and delivery arrangements.
Azuki shaped by Tamba’s history
Tamba Dainagon azuki are highly regarded in Japan for their large size, beautiful red colour, rich flavour and ability to hold their shape when cooked. In fine Japanese confectionery, the appearance and texture of each bean can make a difference to the finished sweet.
Several connections brought us to growing these beans. When we moved to the Oji district of Kasuga, Tamba City, we already loved Tamba Dainagon’s flavour, particularly in Japanese sweets.
Tamba’s Dainagon azuki are said to appear as a local speciality in the 1645 book Kefukigusa. Local records also describe fine beans from Higashinaka in Kasuga, formerly Kokuryo village, being selected as tribute in 1705. Higashinaka is remembered as the birthplace of Tamba Dainagon azuki. Our farm is in Oji rather than Higashinaka itself, but shares the agricultural culture of Kasuga.
We were also fortunate to have a neighbouring farmer who had won repeated awards for azuki quality. He shared our first seeds and advice on growing them. Beginning with local seed and knowledge means a great deal to us.
What makes Tamba Dainagon distinctive
Compared with ordinary azuki, the beans are large, slightly angular and barrel-shaped, with a deep red colour. Depending on variety and cooking conditions, they resist breaking down, making them well suited to zenzai and chunky bean paste, where the beans themselves remain visible.
Flavour, aroma and skin texture are also part of their enduring appeal. However, Dainagon can refer broadly to large azuki; not all Dainagon beans are Tamba Dainagon. Tamba has several longstanding local lines, and more recent selection has also aimed to make growing characteristics more consistent.
Our seeds came from an experienced farmer in Kasuga. We will share more precise lineage information as far as we can verify it.
Soil care begins in spring
Azuki are the last of our main crops to be sown each year. We usually sow directly in the field in mid- to late July, with early August as our rough guide for late sowing.
That gives us spring and early summer to build the soil. We let field vegetation grow, cut it and return it to the ground. Depending on the field, we also consider interim crops to improve soil conditions. We use homemade compost, plant organic matter and carbonised rice husks too.
Around chilli transplanting time, we cover the azuki beds with a thick layer of straw. It suppresses weeds, moderates drying and provides conditions for earthworms and other soil organisms. At sowing, we part the straw roughly every 40 cm and make a small hole in the soil. Sometimes we sow two seeds and retain the stronger seedling after germination. It lets us begin the crop without extensively disturbing the soil.
Supporting branches and working with nature
Azuki begin with steady upright growth, then spread broad branches sideways. Those branches are surprisingly brittle and tend to fall towards the ground as leaves and pods add weight.
We therefore add two levels of supporting string as they grow. With around four or five true leaves, the first strings go along both sides of the bed, with their height adjusted as needed. As the plants fill out, we add a higher level to stop the branches sprawling too far onto the ground.
Azuki have small, beautiful yellow flowers. Butterflies and moths visit, and their caterpillars sometimes eat the leaves. We aim for vigorous plants able to tolerate some feeding damage. That does not mean damage is harmless, but it is part of growing without relying on synthetic pesticides. We use neither synthetic pesticides nor chemical fertilisers on our azuki.
Matching wits with the deer
Insects are not the only azuki enthusiasts: deer love them too. In previous years we had an electric fence around the whole holding and a second one around the azuki. In 2026 we omitted the inner fence. Deer breached the outer one and ate roughly half the planted azuki.
Fortunately, we had also sown another plot. Its original purpose was mainly to return nitrogen and organic matter to former paddy soil. Sown late, in early August, the plants are smaller, but they have good pods. Next year we intend to return to two fences.
Harvesting over repeated walks through the field
Azuki are not harvested in a single pass. One plant can carry green pods, ripening pods and fully brown, dry pods at the same time.
We lightly tap brown pods to listen for the beans rattling inside. The dry ones are picked by hand, while green pods remain. We pass through the field three or four times, sometimes five.
Left too long, ripe pods can split and shed their beans or suffer rain damage. Harvest is usually around mid-October to late November, depending on temperature and sowing date. Occasionally a few pods remain into December.
Slow drying on straw mats, sorting every bean
We spread the picked pods on traditional thick straw mats to finish drying with good airflow. We choose calm, dry weather and avoid prolonged exposure to strong direct sun. When humidity is low, drying may continue overnight in the barn. We do not use an industrial high-temperature dryer for azuki.
Once dry, we split the pods by hand and remove the beans. We separate large pod fragments and use air to remove finer debris. For us, though, an important part of the work comes next.
Quality checked one bean at a time
Wevisually inspect every azuki bean, sorting for colour, shape, size, surface condition and how well it has filled. Alongside obvious damage and discolouration, we check subtle uneven colouring, irregular shapes and small surface marks when selecting beans for sale.
Mechanical sorting plays an important role. Alongside machines that separate sizes and foreign material, modern optical sorters can detect relatively small colour differences. But our aim goes beyond removing beans with conspicuous defects. We want to judge each bean ourselves, including its deep Tamba Dainagon red and well-formed shape, to decide whether it meets the finish we want.
Naturally, it takes a great deal of time. In zenzai and chunky bean paste, where the appearance of the beans shapes the impression of the dish, we believe the beauty of individual beans matters too.
We want each bag to contain beans we have personally checked and chosen, rather than simply harvested. That is our approach to hand sorting at Tamba Miwa Farm. Hand sorting alone does not guarantee flavour, but we value being able to inspect the final quality ourselves.
A richness you can taste
We find these azuki deeply flavoured, with a soft texture. At first we wondered whether we simply thought they tasted good because we had grown them ourselves.
But people who regularly make azuki sweets gave us similar comments about their depth and intensity. Some have also asked to buy from the following year’s harvest.
Slow drying and careful handling are how we try to respect the beans’ colour and eating quality. We have not scientifically compared the effects of drying methods on flavour. Above all, we value the reactions of the people who actually cook them.
Zenzai, chunky bean paste and Japanese sweets
One of our favourite ways to enjoy Tamba Dainagon is zenzai, a sweet azuki soup. The large beans retain their shape in the bowl, looking beautiful while allowing their texture and flavour to shine.
They also suit many Japanese sweets, including dorayaki and manju made with chunky bean paste. We hope you will enjoy them in dishes that show off the beans themselves.
Why we keep growing them here
For us, Tamba Dainagon azuki are more than a crop. They connect Kasuga’s farming history, the knowledge of the neighbour who shared his seed and our daily work in the fields.
We keep learning about soil care, supports and crop rotation, a little each year. Some years go smoothly; in others, negotiations with the deer are less successful.
The aim stays the same: grow good beans, handle them carefully through harvest, drying and sorting, and offer a taste of this place.
For our approach across the whole farm, read How we grow (Japanese).
Purchase and business enquiries
We welcome interest in the next harvest throughout the year. Tell us your preferred quantity, timing and delivery municipality. Enquiries from households, Japanese confectioners, restaurants and shops are all welcome.
After checking harvest quantities and quality following drying and sorting, we explain available amounts, prices, the total including delivery and the delivery method. If stock is already available, we let you know what can be bought then. Orders are confirmed only after you agree to the details.
Registration is free, with no obligation to buy. It does not guarantee stock or a fixed quantity. See the linked information page for seasonal local delivery and shipping arrangements within Japan.
Current products can also be found in our Mercari listings. Please complete Mercari purchases within Mercari.
Frequently asked questions
What are Tamba Dainagon azuki?
Large azuki beans closely linked to the history of Tamba. Valued for their red colour, rich flavour and attractive appearance when cooked, they are widely used in Japanese sweets.
How do they differ from ordinary azuki?
They are generally larger and suit dishes that showcase whole beans. Flavour and texture also depend on variety, growing conditions and cooking.
Are all Dainagon beans Tamba Dainagon?
No. Dainagon can refer broadly to large azuki. Tamba Dainagon has its own regional history and associated varieties and lines.
Why is Kasuga known for them?
Higashinaka in Kasuga is traditionally regarded as their birthplace and is known for local records of a tribute in 1705. Our farm is in Oji, also in Kasuga.
Why do they tend to retain their shape when cooked?
Dainagon-type beans are valued for holding their shape during cooking. Results still vary with cooking methods and bean condition.
Where do you grow them?
In Oji, Kasuga, Tamba City, Hyogo. Our original seeds were shared by an experienced local farmer.
When do you sow and harvest?
We usually direct-sow in mid- to late July and harvest around mid-October to late November. Timing varies by year.
Do you use pesticides or chemical fertilisers?
We do not use synthetic pesticides or chemical fertilisers. We focus on compost, grass and straw organic matter and soil care. We do not hold Organic JAS certification. For details, see How we grow (Japanese).
How do you harvest and dry them?
We hand-pick ripe pods over several rounds and dry them slowly on straw mats. Shelling and final sorting are also done by hand.
Why pick by hand?
Pods ripen at different times. Hand picking lets us take only the dry pods and leave immature ones on the plant.
How do you recommend eating them?
Zenzai and chunky bean paste show off the large beans. They also suit Japanese sweets such as dorayaki and manju.
Where can I find prices?
For direct sales, we ask about quantities and delivery and provide a total including charges before confirmation. Mercari prices are shown in each listing.
Can I register interest in the next harvest?
Yes. Please use the purchase enquiries page. Registration is free and carries no obligation to buy. Weather and quality after harvest affect the saleable quantity, so we cannot guarantee stock. We will contact you again when we know what we can offer.
Why sort every azuki bean by hand?
We inspect each bean’s colour, shape, size, marks and uneven colouring to send only those meeting our standards. Machines also have excellent sorting capabilities, but we value checking final appearance and quality with our own eyes.
References
Sources for history and varietal characteristics. These do not document our own growing experience.