How to Prepare Beche-de-mer from Sea Cucumbers

Beche-de-mer is the dried, processed form of sea cucumbers – soft-bodied marine animals belonging to the phylum Echinodermata that live on ocean floors across the world. Valued as a luxury food in China, Japan, Singapore, and other Southeast Asian countries, this product has been traded for over a thousand years. The preparation of beche-de-mer involves a series of carefully controlled steps: gutting, boiling, skinning, salting, and drying. Each step directly affects the quality, appearance, and market price of the final product. In this post, we break down the entire process from raw sea cucumber to finished beche-de-mer, along with the quality factors that determine its commercial value.

What exactly is beche-de-mer? 🔗

Beche-de-mer – also known as trepang in Indonesian, hai-som in Chinese, and iriko in Japanese – is essentially the body wall of sea cucumbers with the viscera removed, then cleaned, cooked, and dried. The term comes from Portuguese (bicho do mar, meaning “sea animal”). Over 80% of the global sea cucumber catch is marketed in this dried form because drying allows long-term storage without refrigeration – sometimes for over a decade – and it can be produced in remote coastal areas with minimal infrastructure.

Sea cucumbers belong to the class Holothuroidea and are related to starfish and sea urchins. They are benthic creatures, meaning they live on the sea floor, where they feed on organic matter and play an important ecological role as natural recyclers of sediment. Of the roughly 1,700 known species, only about 10 species have significant commercial value in the beche-de-mer trade. The dried form accounts for approximately 95% of all sea cucumber traded annually in key markets like China, Singapore, Malaysia, Korea, and Japan.

Why is beche-de-mer so valuable? 🔗

In Chinese cuisine, sea cucumber is regarded as one of the four great sea delicacies. It is a high-protein, low-fat food traditionally served at banquets, weddings, and important celebrations. Beyond culinary use, traditional Chinese medicine attributes several health benefits to sea cucumber consumption, including supporting joint health, regulating blood pressure, and promoting general vitality.

This cultural demand drives extremely high prices. Some species, such as the sandfish (Holothuria scabra), can fetch up to $1,800 per kilogram in dried form, while the white teatfish (H. fuscogilva) sells for around $401 per kilogram. Market prices in Chinese stores can vary up to tenfold depending on species, body size, and product quality. A study published in PLOS ONE found that average prices across species ranged from US$15 to US$385 per kilogram, with values increasing six- to twelve-fold over the preceding decade.

Species used in beche-de-mer production 🔗

Not all sea cucumbers are suitable for beche-de-mer. The best species have large bodies and thick body walls, which yield a meatier, more desirable product. Some of the commercially important species include:

Holothuria scabra (sandfish) – one of the most highly valued species worldwide, widely harvested across the Indo-Pacific region. Holothuria fuscogilva (white teatfish) – a premium species known for its large size and thick body wall. Holothuria spinifera – commonly processed in Sri Lanka and parts of India. Thelenota ananas (prickly redfish) – another high-value species found in tropical waters. Bohadschia vitiensis – commercially exploited in Sri Lanka and Pacific Island nations. Actinopyga echinites (deep-water redfish) – harvested from the Great Barrier Reef region and parts of Southeast Asia.

Currently, more than 70 countries are engaged in sea cucumber fishing worldwide, targeting around 66 species. Processing methods vary by species because different species have different body wall thicknesses, water retention levels, and chalky deposit characteristics.

Step-by-step processing of beche-de-mer 🔗

The preparation of beche-de-mer follows a general sequence, though processors often have their own species-specific modifications passed down through generations. The core steps, as documented by the FAO and researchers in Pacific Island nations and Sri Lanka, are outlined below.

Step 1: Harvesting and handling 🔗

Sea cucumbers are typically harvested by hand from shallow coastal waters or by divers in deeper areas. Once brought on board a fishing vessel, a small 2-3 cm slit is made near the posterior end (cloaca) of the animal. The body wall is then pressed near the oral region to push out the gut and internal organs quickly. Any remaining water inside the body cavity is also squeezed out. The harvested animals should be placed in smooth-interior plastic containers – not on ice, as ice can damage the delicate body wall. If transport takes time, the seawater in the holding container should be changed every 12 hours.

Step 2: Grading and cleaning 🔗

Before processing begins, sea cucumbers are sorted by species and size. Grading is critical because different species require different boiling times and processing methods. Larger individuals need longer cooking durations than smaller ones. Processing without proper grading leads to inconsistent product quality. After grading, the animals are washed thoroughly in clean seawater to remove slime, sand, and other debris from the body surface.

Step 3: Gutting (evisceration) 🔗

Gutting is the removal of all internal organs from the sea cucumber. A small incision (typically 2.5-4 cm) is made on the ventral side of the animal, starting from the anus and extending partway toward the front end. The opening allows thorough cleaning of the body cavity. Careful gutting is essential – imperfect removal of the mud-filled intestine greatly reduces the final product’s value. In some species like teatfish, the cut is made on the dorsal surface. Certain highly perishable species, such as Stichopus naso, are boiled first and then eviscerated to reduce losses from tissue breakdown.

Step 4: First boiling (cooking) 🔗

After cleaning, the sea cucumbers are boiled in saltwater at about 95°C. The boiling time ranges from 10 minutes to 1.5 hours, depending on the species and size of the specimen. According to the FAO, boiling serves four key purposes: it kills spoilage-causing microorganisms, it contracts and thickens the body wall to a desirable texture, it reduces free water in tissues to speed up subsequent drying, and it may reduce toxin levels in certain species.

The cooking medium can be either natural seawater or freshwater with added salt (at about 32 parts per thousand). Research from Sri Lanka found that using freshwater with added salt produces results comparable to seawater, which is actually preferable where coastal water may be contaminated. Properly cooked sea cucumbers develop a characteristic cooked odour and a rubbery, blubber-like consistency – they should bounce slightly when dropped on the floor. Overcooking causes the body wall to blister and become spongy, which severely lowers quality.

Step 5: Removal of chalky deposits (skin cleaning) 🔗

The skin of many sea cucumber species contains tiny calcareous (chalky) deposits called spicules. These must be removed to improve market value. There are several methods for this. One common technique involves burying the cooked sea cucumbers in moist sand for 12-18 hours – bacteria decompose the outer skin layer, making the chalky deposits easy to peel off. Another method, practised in parts of Southeast Asia and Madagascar, uses papaya leaves or powder. The papain enzyme in papaya dissolves the calcareous material. However, papaya treatment can sometimes remove surface projections that buyers find desirable, particularly in species like H. spinifera. A simpler alternative is to soak the boiled sea cucumbers in freshwater for about 8 hours and then brush the surface clean.

After skin cleaning, the sea cucumbers are washed, rinsed, and reboiled in seawater for 30-45 minutes. This second boiling kills any bacteria introduced during the skin removal step.

Step 6: Salting 🔗

After the first boiling (or after skin removal, for species that require it), the sea cucumbers are salted. Salting limits water loss, preserves the product by restricting microbial growth, and minimises shrinkage during drying. Two methods are used: dry (solid) salt is rubbed directly onto the sea cucumbers, or the animals are immersed in a salt brine solution. In some regions, such as Tonga, sea cucumbers are packed in salt for approximately five days before boiling and drying. Research indicates that solid salt tends to produce better-coloured products, while brine solutions can sometimes cause surface discolouration, especially in species like B. vitiensis and S. naso.

Step 7: Second boiling 🔗

Following the salting stage, sea cucumbers undergo a second, shorter boil – typically around 5-10 minutes. This step further sterilises the product and helps achieve the final desired texture and consistency.

Step 8: Drying 🔗

Drying is what transforms the processed sea cucumber into the shelf-stable beche-de-mer product. The most common method is sun drying on raised platforms or wire mesh trays – not on the ground, which produces inferior products due to slow drying and contamination. Drying can take one to three weeks depending on body wall thickness, surface area, temperature, and humidity. The sea cucumbers should be turned regularly to ensure even drying and prevent mould formation.

In some facilities, electric cabinet dryers are used for faster and more consistent results, though these can sometimes cause excessive shrinkage and surface discolouration. In Japan, the product is sometimes roasted at 70°C before drying. The final product should have a moisture content of about 8-10%, appearing brittle and hard. Since dried beche-de-mer tends to reabsorb moisture over time, periodic re-drying may be needed during long-term storage.

Step 9: Smoking (optional) 🔗

Some premium beche-de-mer undergoes an additional smoking step. Smoke dryers are often simple structures – a 200-litre drum kept horizontal with a wood fire, enclosed in a housing with trays of sea cucumbers arranged above in vertical rows. The choice of wood affects the final flavour and aroma. Smoking also provides additional preservation by further reducing moisture and introducing antimicrobial compounds from the smoke. However, excessive smoking can make the product bitter.

Quality factors that determine market value 🔗

The market price of beche-de-mer varies enormously – and quality assessment is both a science and an art. Exporters and buyers evaluate several key parameters.

Species 🔗

Species is the single biggest determinant of price. High-value species like sandfish and white teatfish command prices many times higher than common, low-value species. This is due to body wall thickness, flavour profile, and cultural preferences in consuming markets.

Size 🔗

Larger beche-de-mer consistently fetches higher prices. For three high-value species (H. fuscogilva, H. lessoni, and H. scabra), research has shown that price per individual increases exponentially with the length of the dried product. This has important implications for fishery management – harvesting sea cucumbers at larger sizes significantly increases economic returns.

Appearance and surface quality 🔗

Buyers look for a uniform, non-distorted shape, even colour (typically dark), and a surface free from scratches, patches, or visible salt deposits. Deformed, bent, or damaged specimens receive significantly lower prices. The finished product should also be free of dirt and have a pleasant odour.

Moisture content and texture 🔗

Good quality beche-de-mer should be hard and dry, with a moisture content in the range of 8-20%. When properly rehydrated before cooking, it should regain some flexibility, indicating that the natural protein structure was preserved during processing. Overly brittle or mushy products suggest processing errors.

Processing weight loss 🔗

During the entire processing chain, sea cucumbers lose a significant portion of their fresh weight. Studies on Sri Lankan species found that weight loss during processing ranged from about 86% to 94%, depending on the species and the processing method used. This means roughly 100 kg of fresh sea cucumber yields only 6-14 kg of dried beche-de-mer – which partly explains the high market prices.

Beche-de-mer trade and conservation concerns 🔗

The beche-de-mer trade is a major source of income for coastal communities in many countries, including Pacific Island nations, Sri Lanka, Madagascar, and parts of Africa. However, the high prices have led to widespread overharvesting. India banned the sea cucumber fishery entirely in 2001 under the Wildlife Protection Act, classifying sea cucumbers as a Schedule I protected species. Despite this ban, illegal harvesting and cross-border smuggling – particularly between India and Sri Lanka – remain significant problems.

Sea cucumbers play a critical ecological role on the ocean floor. They process organic matter, recycle nutrients, and help maintain the health of coral reef ecosystems. Their removal in large numbers can have cascading effects on marine habitats. This has prompted growing interest in sea cucumber aquaculture as a sustainable alternative to wild harvesting, with species like H. scabra being successfully farmed in several countries.

Nutritional profile of beche-de-mer 🔗

Beche-de-mer is a high-protein, low-fat food. Based on research analysing export-quality products, the crude protein content (on a dry weight basis) ranges from approximately 48% to 59%, while fat content is very low – typically between 1.3% and 2.7%, depending on the species. Ash content is relatively high (30-45%), reflecting the mineral-rich nature of the product. This nutritional profile is part of the reason sea cucumber has been valued in traditional medicine for centuries, and modern research continues to investigate its potential antioxidant and anti-inflammatory properties.

Modern processing improvements 🔗

While traditional methods remain the foundation of beche-de-mer production, modern processing techniques are being adopted in some commercial facilities. These include vacuum freeze drying, microwave-assisted drying, heat pump drying, and high-pressure processing. These methods offer better control over temperature and humidity, more consistent results, and improved food safety. However, they require significant capital investment and are not yet practical for small-scale fishers in remote areas – who still produce a large share of the world’s beche-de-mer using traditional sun drying and smoking techniques.

Organisations like the Australian Centre for International Agricultural Research (ACIAR) and the Secretariat of the Pacific Community have published manuals specifically designed for small-scale fishers, providing best-practice processing guidance that can be implemented using village-level resources.

What do you think? Given the high market demand and ecological risks, can aquaculture realistically replace wild harvesting as the primary source of beche-de-mer – or will the traditional fishing-based supply chain continue to dominate? How might better processing standards help small-scale fishers earn more from the same harvest?

References

1. https://www.fao.org/4/ac869e/AC869E11.htm
2. https://en.wikipedia.org/wiki/Sea_cucumbers_as_food
3. https://www.sciencedirect.com/science/article/abs/pii/B9780127999531000209
4. https://news.mongabay.com/2022/02/demand-for-sea-cucumbers-turns-india-sri-lanka-waters-into-trafficking-hotspot/
5. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095075
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC9420059/
7. https://www.sciencedirect.com/science/article/pii/S0308597X17308035
8. https://www.kamakshiayyar.com/editorial/sea-cucumber-illegal-trade-india
9. https://www.aciar.gov.au/publication/books-and-manuals/processing-sea-cucumbers-beche-de-mer-a-manual-pacific-island-fishers