Okinawa seawater salt: every ingredient on the label
青い海 沖縄の海水塩 青い海
The only ingredient is Okinawan seawater. The seawater is taken from about 2,000 m off Itoman, concentrated with a reverse osmosis membrane, and then boiled in flat pans.
Checking the ingredient list against the additives you flagged.
Choose additives to flag →The label on the back
| 名称Name | 食塩 |
|---|---|
| 原材料名Ingredients | |
| 内容量Net content | 120g |
| 製造者Manufacturer | 株式会社 青い海 〒901-0306 沖縄県糸満市西崎町4丁目5-4 |
| 工程Process | 逆浸透膜、平釜、平釜 |
| Energy エネルギー | 0kcal |
| Protein, fat, carbohydrate たんぱく質、脂質、炭水化物 | 0g |
| Salt equivalent 食塩相当量 | 91.1g |
| Calcium カルシウム | 400mg |
| Potassium カリウム | 160mg |
| Magnesium マグネシウム | 180mg |
Copied from the package as of the date checked. The label is shown in Japanese as printed; tap an ingredient to see its English name and role. The links in the table below lead to our Ingredients A–Z and food additive database. There is no best-before date or storage method on the label. Under the Food Labeling Standards, table salt is a food for which the best-before date and storage method may be omitted. The package says that it may absorb moisture and clump but that quality is not affected.
Ingredients, one by one
| On the label | Type | Role | Notes |
|---|---|---|---|
| 海水（沖縄県）seawater | Ingredient | Base of the salt (the only ingredient) | The package explains that the seawater is taken from about 2,000 m off Itoman, Okinawa. Under the industry's fair competition code, salt labels have a set field for the “製造方法” (production method). For this product it reads “海水（100% 沖縄県）” (seawater, 100% Okinawa) and “工程：逆浸透膜、平釜、平釜” (process: reverse osmosis membrane, flat pan, flat pan). The reverse osmosis membrane is a step that concentrates seawater through a membrane. A flat pan (平釜) is a step that boils down brine, or crystallizes salt, in a pan that is not sealed with a lid. The process is written in order, so it appears that the concentrated seawater is boiled in flat pans in two stages (what each of the two stages involves has not been checked against the manufacturer's materials). |
Not found in the ingredient list
This is not the maker's “not used” claim. These are things often seen in similar products that we checked are not written in this product's ingredient list. Additives carried over from ingredients may not be declared, so this does not mean they are absent (about additives not written on labels).
Next to a typical product
海水（沖縄県）
天日塩（メキシコ）／炭酸マグネシウム
The process is “溶解、立釜、乾燥、混合” (dissolving, sealed pan, drying, mixing). Sun-dried salt from Mexico is dissolved in water, boiled down again in a sealed pan (立釜) and dried, and magnesium carbonate is mixed in to make it less likely to clump. The quality standard is 99% or more sodium chloride. Also, under the salt fair competition code, a salt may not simply say “無添加” (additive-free) or “ミネラル豊富” (rich in minerals).
Good points and concerns
+Good points
- The only ingredient is seawater, with 0 additives
- No anti-caking additive (such as magnesium carbonate) is added
- The label gives the amounts of calcium, potassium and magnesium as estimated values per 100 g
−Concerns
- ¥259 for 120 g (about ¥216 per 100 g). More expensive than typical table salt
- Because there is no anti-caking agent, it can clump in humid conditions (also noted on the package)
- On the company's product page the process is still “逆浸透膜、立釜、立釜” (reverse osmosis membrane, vertical pan, vertical pan). The official shop says “2026年4月1日にリニューアルし、製造方法を一部変更” (renewed on 2026-04-01, with part of the manufacturing method changed), and the package in hand says flat pan (平釜). Check the label on the package when you buy
Related articles
Sources
- Okinawa seawater salt Aoi Umi 120 g | Shimamasu Honpo official online shop
- Okinawa seawater salt Aoi Umi | Aoi Umi Co., Ltd. (product information)
- Fair Competition Code on Labeling of Edible Salt and its Enforcement Rules | Edible Salt Fair Trade Council
- Glossary (reverse osmosis membrane, flat pan, etc.) | Edible Salt Fair Trade Council
- Shokutaku-shio (table salt) series | Salt Industry Center of Japan
- Food Labeling Standards Q&A (omitting best-before date and storage method for salt) | Consumer Affairs Agency
- Label on the back of the package (checked 2026-09-28)
This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.
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