**Indonesian Eucheuma cottonii — botanically Kappaphycus alvarezii, locally called cottonii or katoni — is a warm-water red seaweed and the world’s leading source of kappa carrageenan. Indonesia grows more of it than any other nation, feeding two very different markets: industrial carrageenan processing and the Western health-food sea moss trade.**
What exactly is Eucheuma cottonii?
Eucheuma cottonii is the trade name Indonesian farmers and exporters use for the red seaweed scientifically named Kappaphycus alvarezii. You will also hear the local names cottonii, katoni, sacul, and sakul. It is a different plant from Eucheuma spinosum, which yields iota carrageenan; cottonii is prized because it yields kappa carrageenan, the gelling agent used across the food industry.
The species is tropical by nature. It grows naturally within roughly 20 degrees latitude of the equator across the Indo-Pacific, concentrated in Southeast Asia, and thrives in the warm, clear waters that ring the Indonesian archipelago. Growth is fast: in warm Indonesian conditions a crop can reach about ten times its planted mass in 45 to 50 days, which is why farmers run several harvest cycles a year.
Cultivation has a datable history. Cottonii originally came from the Philippines and became cultivable in Indonesia in 1974. Today most of it is farmed by the longline method — plastic rope tied to lines that are anchored to poles driven into the seabed, with young thalli tied along the rope and left to grow in the current.
Why does carrageenan make this seaweed valuable?
Carrageenan is the reason a humble rumput laut becomes an export commodity. Kappa carrageenan, extracted from cottonii, forms firm gels and stabilises dairy, processed meat, toothpaste, and plant-based drinks. Industry sources describe Indonesia as the world’s largest producer of red seaweeds, and cottonii is the backbone of that output.
For B2B buyers the practical questions are gel strength, carrageenan yield, and cleanliness. Some Indonesian processors market cottonii specifically as a high-gel-strength, low-impurity kappa source. Domestic processing is real too: domestic carrageenan processors produce food-grade carrageenan from both cottonii and spinosum in East Java, near Surabaya, and Indonesia has a real, expanding domestic carrageenan-processing base around Surabaya and East Java that handles cottonii, spinosum and Gracilaria.
One honesty note that matters for buyers: any figure for carrageenan yield, gel strength, moisture, ash, or heavy metals should be treated as a claim only when it comes from a specific batch Certificate of Analysis. Do not plan a contract around a marketing number.
Who buys Indonesian cottonii, and in what form?
There are two buyers, and they want two different products. If you are sourcing at volume, our eucheuma cottonii wholesale desk maps both.
- Industrial carrageenan processors buy raw, sun-dried cottonii bales, tolerate higher moisture, and care most about carrageenan yield per tonne.
- Food, nutraceutical and private-label health brands buy cleaned, food-grade cottonii — the material Western marketing calls “gold sea moss” — and pay far more per kilogram for lower moisture and near-zero foreign matter.
That split is the single most important thing to understand before requesting a quote, because the two markets sit at completely different price points.
How is cottonii graded by moisture and cleanliness?
Grade is defined mostly by moisture and impurity, and documented trader specs vary. Some list moisture 35–37% with foreign matter 3% max; others quote moisture 35–37% with impurity 5% max, sun-dried; another lists moisture 37–39% with impurities 2% max; and a premium “Dried Raw Algae Grade A” runs moisture under 35% with impurities under 2%.
| Grade tier | Moisture (typical) | Impurity / foreign matter | Main buyer |
|---|---|---|---|
| Commodity / salted | 37–39% | up to 5% | processors |
| Standard sun-dried | 35–37% | around 3% | processors / traders |
| Premium Grade A | under 35% | under 2% | food-grade / private label |
Prices follow grade. The band below is FOB indikatif per 2026, and it moves with harvest, moisture and grade; a final quote is confirmed on spec and MOQ.
| Product | FOB band (USD/kg) |
|---|---|
| Raw dried cottonii — commodity/salted, higher moisture | 4–7 |
| Raw dried cottonii — standard | 6–9 |
| Raw dried cottonii — higher-grade, low-moisture, clean | 9–12 |
| Cleaned/washed food-grade bulk wholesale | 25–55 |
Branded Western retail sea moss sits far above these numbers, but that shelf price is not an FOB quote. And a caution on figures floating around: one export listing quoted FOB “starting at $1330/Bags” — that is per bag and undated, not per kilogram, and it shifts with volume, packaging and destination.
Where is cottonii grown and how does it reach export?
Indonesian cottonii comes from a wide arc of provinces: Maluku, West Nusa Tenggara (NTB), East Nusa Tenggara (NTT), South Sulawesi (Bone, Maros, Jeneponto, Takalar, Luwu, East Luwu), West Lombok, and North Kalimantan. Surabaya and wider East Java act as the main processing and export gateway. Bali works as a sourcing and logistics hub rather than a documented large production zone.
Seasonality shapes both quality and price. Monsoon and rainy seasons lengthen sun-drying, which lifts moisture and can lower yield, while ice-ice disease and epiphytes threaten crops in the water.
Once dried, cottonii is baled in polypropylene cloth in 50 kg or 100 kg bags. Container loading runs roughly 15 MT in a 20ft, 23 MT in a 40ft, and 25 MT in a 40HC — about 350 hundred-kilo bales per 40HC. Shelf life is about 12 months stored cool, dry, sealed and out of direct sunlight. Typical order sizes start at a 1 MT trial and rise to 20–100 MT contracts, and standard export paperwork covers COA, MSDS, fumigation, phytosanitary and COO, with Halal and HACCP/ISO 22000 supplied on request.
A closing reminder for the health-market reader: sea moss is a food and ingredient, not medicine. It is worth knowing exactly what you are buying — but no honest supplier will promise it cures anything, nor guarantee customs clearance.
Frequently Asked Questions
Is Eucheuma cottonii the same species as Kappaphycus alvarezii?
Yes. Eucheuma cottonii is the long-standing trade name for the species botanists classify as Kappaphycus alvarezii; Indonesian farmers also call it cottonii, katoni, sacul or sakul. The commercial name stuck from the early cultivation era, while the scientific name reflects a later reclassification. Both refer to the same kappa-carrageenan red seaweed.
Is Indonesian cottonii the same as Caribbean sea moss?
Not exactly. Much Caribbean “sea moss” is Gracilaria, a different red seaweed, while Indonesian cottonii is Kappaphycus alvarezii and the leading kappa-carrageenan source. Both are edible red seaweeds used to make gels, but they differ in gel character and carrageenan profile. As a food, neither is medicine, and neither should be sold with disease-cure claims.
How long does Eucheuma cottonii take to grow before harvest?
In warm Indonesian waters a longline crop can reach roughly ten times its planted mass in about 45 to 50 days, which allows several harvest cycles per year. Growth slows and drying takes longer during monsoon and rainy seasons, when higher moisture and risks like ice-ice disease and epiphytes can reduce both yield and grade.