Kōmi, Ma Kombu, 10-Year Aged White Bay (Shiroikuchihama), 500g
Wild Shiroikuchihama ma kombu, Grade 1, aged ten years. Kombu for a clear, refined dashi.
白口浜天然真昆布 (Shiroikuchihama wild ma kombu), labelled 10年熟成 (aged ten years) and 1等検 (Grade 1 inspected), packed by Tsuku Shin (佃真) for the Kōmi range. Ageing rounds off the raw marine edge of fresh kelp and gives a dashi of real clarity. 500g pack.
More from the Kōmi kombu range: 3-Year Aged Black Bay Ma Kombu (500g), Ma Kombu, A Grade (500g) and White Kombu (200g).
Why Chefs Choose This
- Shiroikuchihama origin: the white-mouth shore, known for a clear, elegant dashi.
- Ten-year ageing: stated on the label; ageing mellows the raw seaweed note.
- Grade 1 inspected: 1等検, the top class of Japan's kombu inspection.
- Wild-harvested: 天然 (tennen) on the label: wild kelp, not rope-farmed.
How to Use
- Ichiban dashi: cold-soak a 10cm piece in 1L water for 30 to 60 minutes, then heat to just below boiling and lift out.
- Clear soups: suimono, chawanmushi and shabu-shabu broth, wherever the dashi is the star.
- Niban dashi: re-simmer the used kombu with bonito for a fuller second stock.
- Kombu-jime: press sashimi-grade white fish between softened sheets for a few hours.
Ma kombu (真昆布, true kelp) is the benchmark kelp for dashi, and the coast of Donan in southern Hokkaido, around Hakodate, is its classic ground. Three named shores there are graded separately: Shiroikuchihama (白口浜, white-mouth shore), Kurokuchihama (黒口浜, black-mouth shore) and Motomachihama. It was kombu dashi that led the chemist Kikunae Ikeda to isolate glutamate in 1908 and name the taste umami. Shiroikuchihama kombu is the one chosen when clarity and finesse matter most.
Learn more: What is Kombu?
Why does aged kombu make better dashi?
Fresh-season kombu makes good dashi, but it holds more moisture and a stronger raw marine character. Stored and aged, the kelp dries further and its harsher seaweed notes fade, leaving a stock that is cleaner on the palate and more transparent in colour, with a rounded, sweet savouriness. It is the same principle as ageing cheese or dry-ageing beef: time takes away what you do not want. Ten years is a long rest, and it shows in a dashi that is calm, clear and long.
| Type | Ma kombu 真昆布 (true kelp) |
| Brand | Kōmi |
| Producer | Tsuku Shin 佃真 |
| Harvest Area | 白口浜 Shiroikuchihama, Hokkaido |
| Harvest Method | 天然 Tennen (wild) |
| Grade | 1等検 (Grade 1 inspected) |
| Ageing | 10 years (熟成) |
| Origin | Hokkaido, Japan |
| Net Weight / Format | 500g clear bag |
| Best Used As | Premium clear dashi |
What is Shiroikuchihama kombu?
Shiroikuchihama (白口浜, white-mouth shore) is one of the named ma kombu shores on the Donan coast of southern Hokkaido, alongside Kurokuchihama and Motomachihama. Kombu from each shore is graded separately. Shiroikuchihama is valued for a clear, elegant dashi with a refined savouriness, which makes it the choice for clear soups where the colour and clarity of the stock matter as much as the flavour.
What is the difference between wild and farmed kombu?
Wild kombu (天然, tennen) grows naturally on the seabed, anchored to rock, and usually takes two years or more to mature. Farmed kombu (養殖, yoshoku) is grown on ropes and is often harvested sooner. Wild kelp tends to be thicker and denser, and is generally regarded as giving a more complex dashi. The tennen mark on this label confirms it is wild-harvested.
How is kombu graded in Japan?
Dried kombu in Hokkaido is inspected and graded on qualities such as thickness, width, colour, dryness and freedom from damage. Grade 1 (1等検) is the top class. Lower grades are still usable but may be thinner or carry cosmetic marks. For dashi-led cooking where quality is the point, Grade 1 is the professional choice.
SKU : K0187