Tsuku Shin, 3 Year Aged Ma Kombu, Kurokuchihama, Grade 1, 500g
Wild Hakodate Kombu, Aged Three Years for Professional Dashi
Ma kombu (真昆布) is the highest-grade kelp in Japanese cuisine — the foundation of refined dashi stock. Tsuku Shin's 3 Year Aged Kurokuchihama Ma Kombu (黒口浜天然真昆布 3年熟成) is wild-harvested from Kurokuchihama in Hakodate — one of three elite kombu-producing shores in Hokkaido — graded 1等検 (Grade 1 Inspected), then aged for three years. That ageing concentrates the natural glutamic acid, reduces moisture, and mellows the raw marine edge to produce a cleaner, more umami-rich dashi than fresh-season kombu. Kurokuchihama is known for producing a bolder, more robust stock than its neighbouring shores — making this the professional choice for kitchens that want depth and body in their dashi rather than delicacy alone.
Why Chefs Choose This
- Kurokuchihama origin: One of Hakodate's three named shores. Kurokuchihama ma kombu is prized for producing a fuller-bodied, more robust dashi compared to the lighter, more elegant stock from neighbouring Shiroikuchihama.
- 3 year ageing: Controlled storage concentrates glutamic acid (umami) and reduces the raw seaweed character. Three years is the sweet spot for kitchens that want the benefits of ageing without the premium of decade-aged kombu.
- Grade 1 Inspected: 1等検 — the top classification under Japan's kombu grading system, assessed on thickness, colour, width, and absence of defects.
- Wild-harvested (天然): Not farmed. Wild ma kombu develops naturally in the tidal currents of the Tsugaru Strait, producing a denser, more flavourful leaf than cultivated alternatives.
How to Use
- Ichiban dashi (first stock): Cold-soak a 10cm piece in 1L water for 30–60 minutes, then heat slowly to just below boiling and remove. Produces a rich, full-bodied stock with deep umami.
- Noodle broths & hot pots: The bolder character of Kurokuchihama kombu makes it well-suited to ramen, udon, shabu-shabu, and nabe — dishes where the dashi needs to stand up to stronger flavours.
- Niban dashi (second stock): Re-simmer the used kombu with bonito flakes for a robust everyday stock — nothing wasted.
- Kombu-jime: Cure sashimi-grade fish between two sheets for 2–4 hours. The aged kombu transfers umami more readily than fresh kombu.
How does Kurokuchihama kombu differ from Shiroikuchihama?
Hakodate's three named shores each produce ma kombu with a distinct character. Shiroikuchihama (白口浜) is known for clarity and elegance — a refined, delicate dashi favoured in Kyoto kaiseki. Kurokuchihama (黒口浜) sits at the other end of the spectrum: it produces a fuller-bodied, more robust stock with a deeper umami hit and slightly darker colour. Motomachihama falls between the two. For professional kitchens, the choice depends on the application. Kurokuchihama is the better match when the dashi needs to carry heavier dishes — noodle broths, hot pots, braised preparations — where a lighter stock would get lost. Both are exceptional; they're just tuned differently.
Product Details
| Type | 真昆布 — Ma Kombu (True Kelp) |
| Producer | つく新 Tsuku Shin |
| Harvest Area | 黒口浜 Kurokuchihama, Hakodate, Hokkaido |
| Harvest Method | 天然 Tennen (Wild-Harvested) |
| Grade | 1等検 (Grade 1 Inspected) |
| Ageing | 3年熟成 (3 Year Aged) |
| Weight | 500g |
| Storage | Store in a cool, dry place away from direct sunlight. Reseal after opening. |
What is Kurokuchihama kombu?
Kurokuchihama (黒口浜) is one of three named kombu-producing shores in the Hakodate region of southern Hokkaido, alongside Shiroikuchihama and Motomachihama. These three shores have been recognised for centuries as producing Japan's finest ma kombu. Kurokuchihama kombu is valued for producing a fuller-bodied, more robust dashi than its neighbours — a stock with deeper umami and a slightly richer colour, well-suited to dishes where the broth needs to carry weight.
Why age kombu for three years?
Ageing kombu in controlled storage reduces moisture content and concentrates the natural glutamic acid responsible for umami. It also mellows the raw marine character that can dominate fresh-season kombu. Three years is considered an excellent ageing period for professional use — long enough to see a meaningful improvement in dashi quality, while remaining more accessible in price than kombu aged for a decade or more. Many high-end Japanese restaurants use 3-year aged kombu as their everyday dashi kombu.
What is the white powder on the surface of kombu?
The white powdery residue on dried kombu is mannitol, a natural sugar alcohol that crystallises on the surface as the kelp dries and ages. It is not mould or dirt and should not be washed off — it contributes to the overall flavour. Simply wipe the surface lightly with a damp cloth before use if needed. The presence of mannitol is a sign of good quality; heavily processed or lower-grade kombu often has less visible surface mannitol.
SKU : K0219