**An Indonesian seaweed specification sheet reads top to bottom as a quality contract: species and grade first, then the four numbers that decide price — moisture, foreign matter (impurity), ash, and carrageenan yield — followed by packaging, container load, and trade terms. Match every figure to a batch COA before you wire funds.**
Most first-time cottonii buyers scan a spec sheet for the price and stop there. That is how they end up paying for water and sand. The document in front of you is a set of promises about one product — dried Eucheuma cottonii — and each line changes what a kilogram is actually worth. Here is how to read it the way a carrageenan processor or private-label brand does.
What is a cottonii spec sheet, and why does it read like a contract?
The header names the product. Indonesian dried sea moss is almost always Eucheuma cottonii, the red seaweed (local name rumput laut) also catalogued as Kappaphycus alvarezii and known on the coast as cottonii, katoni, or sacul. It is the primary source of kappa carrageenan; its cousin Eucheuma spinosum yields iota carrageenan. If the header says spinosum or Gracilaria, you are looking at a different raw material with a different gel behaviour.
Read every sheet in the same order: species and grade at the top, physical parameters in the body, then packaging, container capacity, documents, and trade terms below. Treat each parameter as a claim rather than a guarantee until a batch Certificate of Analysis (COA) confirms it. Industry sources describe Indonesia as the world’s largest producer of red seaweeds, so you will see many sheets — read them the same way and they become comparable.
Which numbers move the price?
Four figures do most of the work in a negotiation: moisture, foreign matter (impurity), ash, and carrageenan yield or gel strength. Documented grade specs vary by trader, which is the honest reality of this market. Published dried-cottonii listings sit roughly like this:
| Grade / listing | Moisture | Impurity (foreign matter) | Drying note |
|---|---|---|---|
| Standard commodity | 35–37% max | 3% max | — |
| Sun-dried lot | 35–37% | 5% max | sun-dried |
| Higher-moisture lot | 37–39% | 2% max | — |
| Premium “Dried Raw Algae Grade A” | under 35% | under 2% | Grade A & B selections |
Lower moisture means more dry seaweed per kilogram, so a sub-35% Grade A lot commands more than a 37–39% lot that is partly water. Foreign matter — sand, salt residue, shell, tie-string, epiphytes — lowers the usable fraction; a 3% cap allows up to 30 grams of non-product per kilo. Ash and carrageenan yield matter most to processors, because they predict how much finished carrageenan a container will actually produce.
As a working reference, raw dried cottonii sits at roughly USD 4–12/kg FOB (commodity or salted higher-moisture 4–7, standard 6–9, higher-grade low-moisture clean 9–12), while cleaned, washed food-grade bulk runs USD 25–55/kg. These are FOB indikatif per 2026 and move with harvest, moisture, and grade; a final quote follows spec and MOQ. Branded Western retail sea moss is priced far above these and is not a wholesale FOB reference.
How is packaging and bale weight described?
The packaging lines look mundane, but they protect the cargo through a 30–60 day journey and tell you how the seaweed was handled. Standard Indonesian export packing is bales wrapped in polypropylene cloth, filled into 50 kg or 100 kg bags. Shelf life is about 12 months when stored cool, dry, sealed, and away from direct sunlight — so a vague or missing packaging line is a genuine risk, not a formality. If a sheet is silent on bale wrapping or bag weight, ask the exporter or an established seaweed bale supplier to confirm the wrap material and net weight per bale before you commit to a container.
Check three things on the packaging line: the wrap (polypropylene cloth resists moisture ingress), the bag weight (50 kg bags handle more easily; 100 kg bags load denser), and any note about baling pressure or strapping, which affects how many bales fit a container.
What do the container and loading lines mean?
Loading figures let you sanity-check the offer against reality. Typical published capacities are:
- 20ft container: about 15 MT
- 40ft container: about 23 MT
- 40ft high-cube (40HC): about 25 MT, roughly 350 bales of 100 kg
Some exporters run multiple FCL per month, which tells you the supplier operates at industrial scale rather than trading a single lot. If a sheet quotes a container weight far outside these ranges, ask why — over-stuffing risks damage, under-loading raises your per-kilo freight.
How do you verify the sheet against real documents?
A spec sheet is a claim; the document pack is the evidence. For Indonesian seaweed exports, the standard set is:
- Certificate of Analysis (COA) — the batch proof of moisture, ash, foreign matter, microbiology, heavy metals, and carrageenan yield
- Material Safety Data Sheet (MSDS)
- Fumigation Certificate
- Phytosanitary Certificate
- Certificate of Origin (COO)
Halal and HACCP/ISO 22000 certification are usually supplied on request. The single most important rule: any moisture, ash, foreign-matter, microbiological, heavy-metal, or carrageenan-yield figure is only trustworthy when it comes from a specific batch COA — not from the marketing sheet. For a large contract, draw your own sample and run independent lab testing.
What trade terms and payment should you expect?
The commercial block usually offers FOB, CIF, or CNF, with delivery 30–60 days after payment is approved. Payment is typically by T/T, 100% irrevocable LC at sight, or 100% advance, shipped worldwide. Read this block for what it does not say as much as what it does: no supplier can honestly guarantee customs clearance in your country, and no printed figure is a contract until confirmed against a batch.
Volume expectations are straightforward. A typical MOQ starts at 1 MT for a trial and rises to 20–100 MT for contracts, with a container holding roughly 20–25 MT. Start with a trial lot, verify the COA against your own testing, then scale — that sequence protects you far better than any single number on the sheet.
Frequently Asked Questions
Does a higher moisture percentage always mean lower quality cottonii?
Not automatically, but it means less dry seaweed per kilogram and faster spoilage risk. A 37–39% moisture lot carries more water weight than a sub-35% Grade A lot, so you effectively pay for water. Judge moisture alongside foreign matter and drying method, and always confirm the reading against the batch COA rather than the marketing sheet.
What does “foreign matter 3% max” actually include on a spec sheet?
Foreign matter, sometimes labelled impurity, covers everything that is not clean seaweed: sand, salt residue, shell, tie-string, epiphytes, and other debris. A 3% cap means up to 30 grams per kilogram may be non-product. Lower percentages raise usable carrageenan yield, so processors and food buyers scrutinise this line more closely than almost any other figure.
Can I trust the carrageenan yield number printed on a cottonii spec?
Treat printed yield, gel strength, ash, and heavy-metal figures as indicative values until a batch-specific Certificate of Analysis confirms them. Yield shifts with harvest season, drying, and cleaning. Ask for a recent COA and, for large contracts, commission independent lab testing on a sample you draw yourself before signing anything.