Traditional Fish Preservation Methods: Dried and Cured Fish

Fish is one of the most perishable food items in the world. Without some form of preservation, fresh fish begins to spoil within hours of being caught. For thousands of years, communities across the globe – especially in tropical and coastal regions – have relied on drying, salting, and smoking to extend the shelf life of their catch. These traditional methods remain critical today, particularly in regions where modern cold-chain infrastructure is limited. In fact, approximately 17% of all fish caught in India is still sun-dried, and across the developing world, dried and cured fish products continue to serve as an affordable, nutrient-dense source of protein for millions of people.

Why fish needs to be preserved 🔗

Fresh fish typically contains 75 to 80% water, which creates an ideal environment for bacteria and enzymes that cause spoilage. At ambient tropical temperatures, unpreserved fish can become unfit for consumption in less than 12 hours. This is a significant challenge in countries like India, Bangladesh, Indonesia, and Myanmar, where large volumes of fish are landed daily at small, often remote, coastal and inland centres that lack refrigeration.

Traditional preservation methods address this problem by either reducing moisture content or increasing salt concentration in the fish tissue – or both. When water activity drops below a critical threshold (around 0.60), virtually all spoilage-causing bacteria, yeasts, and moulds become inactive. This is the fundamental science behind every dried and cured fish product found in markets from Tamil Nadu to West Bengal to Southeast Asia.

Sun drying: the oldest and simplest method 🔗

Sun drying is the most ancient form of fish preservation known to humanity. It requires nothing more than sunlight, air movement, and time. The basic process involves cleaning the fish, removing scales and internal organs (for larger species), and laying them out on elevated platforms, bamboo mats, concrete surfaces, or even sandy beaches.

How sun drying works 🔗

The combination of solar heat and wind causes moisture to evaporate from the fish’s surface. As the outer layers dry, moisture from deeper within the tissue migrates outward and is also removed. Under favourable conditions – temperatures between 25-35°C, low humidity, and good airflow – small fish like anchovies can be adequately dried in 2 to 3 days. Larger, fleshier species such as ribbon fish or Bombay duck may take 5 to 7 days. Successful drying reduces the fish’s moisture content to roughly 15-25%, at which point microbial activity is negligible and the product can be stored for several months.

Limitations of sun drying 🔗

Despite its simplicity, sun drying has well-known drawbacks. It is entirely weather-dependent – cloudy skies, rain, or high humidity during monsoon seasons can interrupt the process and lead to partial spoilage. Open-air drying also exposes the fish to dust, insects, birds, and animal contamination. Studies from Odisha’s fishing communities show that most traditional sun drying is done without protective measures, which can compromise the hygiene and safety of the final product. To address these issues, organisations like India’s National Fisheries Development Board (NFDB) have promoted solar fish drying units and raised platforms with mesh covers that protect fish while still leveraging free solar energy.

Salting: preservation through osmotic dehydration 🔗

Salt has been used as a preservative for fish since prehistoric times. Its effectiveness lies in reducing water activity through osmotic pressure. When salt is applied to fish, it draws moisture out of the tissue while simultaneously penetrating the flesh. This creates a highly saline internal environment where most bacteria simply cannot survive. There are two main forms of salt-curing used in the fish industry: dry salting and wet salting (brining or pickle-curing).

Dry salting 🔗

In dry salting, cleaned and often split fish are layered with coarse salt – typically at a ratio of about 1 part salt to 3 parts fish by weight. The salt draws out moisture through osmosis, and the resulting brine drains away. Over the course of 24 to 48 hours (or longer for larger fish), the flesh’s water content drops significantly. In heavy-cure or hard-cure salting, the process is taken further by forcing warm air over the surface until the water content drops to around 20% and salt concentration reaches roughly 30%. This produces an extremely shelf-stable product suited to warm, humid climates where refrigeration is unavailable.

Wet salting (brining) 🔗

Wet salting involves submerging fish in a concentrated brine solution, typically containing 15-25% salt by weight. This method ensures more uniform salt penetration compared to dry salting, making it especially useful for larger fish species that might not cure evenly when simply packed in dry salt. The curing period ranges from several hours to over a week, depending on the size and thickness of the fish.

Many traditional communities combine both methods – starting with dry salting to remove initial moisture, then finishing with a brine soak to ensure thorough preservation. After salting, the fish are usually sun-dried to further reduce moisture and achieve the desired final texture.

Smoking: flavour and preservation combined 🔗

Smoking is one of the oldest preservation techniques, and it works through multiple mechanisms simultaneously. Heat partially cooks the fish, the smoke deposits antimicrobial chemical compounds (phenols and aldehydes) on the surface, and the process removes moisture – all while infusing a characteristic flavour that is prized across many cuisines.

Cold smoking vs. hot smoking 🔗

There are two main approaches. Cold smoking is carried out at temperatures below 29-30°C. It does not cook the fish and focuses primarily on flavour development and surface preservation. Hot smoking, which is more common, exposes the fish to temperatures of 60-80°C or higher, partially or fully cooking the flesh while simultaneously preserving it. In traditional practice across many parts of Africa and Asia, simple smoking structures built from bamboo, metal sheets, or earthen kilns are used to suspend fish above a smouldering fire of wood chips or sawdust.

The smoking process 🔗

Before smoking, fish are typically brined in a salt solution to enhance flavour and aid preservation. They are then partially dried on racks. As the brine on the surface dries, dissolved proteins create a glossy, attractive skin known as the pellicle – a quality marker in commercial smoked fish. The fish are then placed in kilns or smokehouses and exposed to smoke for several hours. The result is a product that has reduced moisture, antimicrobial surface protection, and a distinctive smoky taste.

Economic importance of dried and cured fish 🔗

Dried and cured fish products are far more than a survival food – they represent a major component of the fisheries economy in many developing nations, particularly across South and Southeast Asia.

Role in India’s fisheries sector 🔗

India is one of the world’s largest fish-producing countries, and a substantial share of its catch is still processed using traditional methods. In states like Gujarat, Tamil Nadu, Kerala, West Bengal, and Odisha, dried fish processing provides livelihoods for thousands of small-scale operators, many of whom are women. Women in coastal communities typically dominate the processing, drying, and marketing stages of the supply chain, making this sector an important source of female employment and household income.

The value addition from drying is significant. A kilogram of fresh fish that might sell for a modest price at the landing centre can command a substantially higher price once properly dried and cured. This price differential helps fishing families maximise income from their catch and compensates for the 30-40% post-harvest losses that commonly occur with fresh fish in areas lacking cold storage.

Significance across Asia 🔗

Dried fish is a dietary staple across large parts of Bangladesh, Sri Lanka, Myanmar, Indonesia, the Philippines, and Thailand. The FAO recognises dried fish as a critical product for food security in South and Southeast Asia, supporting ongoing research into the gendered economy of the dried fish trade across six countries in the region. Fish products are among the most heavily traded natural food commodities in the world, and the Asia-Pacific region is at the centre of this trade. Countries like Thailand, Vietnam, Indonesia, and India are major exporters, and dried, salted, and cured products form an important segment of this trade – particularly for domestic consumption in rural and low-income communities.

Nutritional value of dried and cured fish 🔗

One of the key advantages of drying fish is that the process concentrates nutrients. As water evaporates, proteins, minerals, and vitamins become more concentrated per gram of the final product. Research published in the journal Foods notes that the protein content of sun-dried fish can range from 49% to over 62%, depending on the species used. Dried fish is also rich in calcium, phosphorus, iron, and B vitamins, and it provides essential omega-3 fatty acids (EPA and DHA) that support cardiovascular health and brain development.

For rural populations in developing countries, dried fish is often the most reliable and affordable source of animal protein available year-round – including during monsoon seasons when fresh fish is scarce and agricultural protein sources may be limited.

Quality and safety challenges 🔗

While traditional preservation methods have stood the test of time, they are not without problems. Open-air sun drying can lead to contamination by insects, dust, and microorganisms. Improperly salted fish may not achieve sufficient dehydration, leading to spoilage during storage. In some regions, harmful chemical preservatives like organochlorine pesticides have been used to combat insect infestation on drying fish – a practice that poses serious health risks to consumers.

Additionally, the accumulation of heavy metals in fish from polluted waterways is a growing concern. Studies from Bangladesh have identified elevated levels of lead, mercury, and chromium in certain dried fish products, underscoring the need for better regulation of both aquatic environments and processing standards.

Modern improvements 🔗

Efforts are underway across the region to modernise traditional practices without losing their economic accessibility. Solar cabinet and tunnel dryers offer an enclosed drying environment that protects fish from contamination while still using free solar energy. Improved packaging – including vacuum sealing and moisture-barrier bags – can significantly extend the shelf life and safety of dried products. Organisations like Tamil Nadu Agricultural University (TNAU) and ICAR-CIFT are actively researching and promoting hygienic drying technologies suited to small-scale producers.

The cultural significance of dried fish 🔗

Beyond economics and nutrition, dried and cured fish hold deep cultural importance. In West Bengal, shutki (dried fish) is a beloved ingredient in regional cuisine, often cooked with leafy greens and brinjal. In Maharashtra, Bombay duck is rehydrated and prepared as a curry. In Japan, katsuobushi (dried bonito) is the foundation of dashi broth and a cornerstone of Japanese cooking. In Nigeria and Ghana, smoked fish is central to traditional soups and stews. These products represent centuries of accumulated knowledge about how to transform a perishable catch into something that nourishes communities through lean seasons and brings distinctive flavours to the table.

Looking ahead 🔗

As global fish production continues to grow and demand for affordable protein rises, traditional preservation methods will remain essential – particularly in regions where cold-chain infrastructure is still developing. The challenge lies in upgrading hygiene and safety standards without pricing small-scale producers out of the market. Combining time-tested techniques like salting and sun drying with modern innovations like solar dryers, improved packaging, and quality monitoring can help ensure that dried and cured fish products remain safe, nutritious, and economically viable for generations to come.

What do you think? Given the deep cultural roots and economic importance of traditional fish preservation in coastal communities, how can governments and NGOs best support the modernisation of these practices without disrupting the livelihoods of small-scale producers? And in your region, is dried or cured fish still a significant part of the local diet?

References

1. https://link.springer.com/chapter/10.1007/978-3-031-62462-9_3
2. https://www.britannica.com/topic/fish-processing/Curing
3. https://en.wikipedia.org/wiki/Dried_fish
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC9562176/
5. https://www.academia.edu/103938756/Traditional_fish_processing_in_Odisha_India
6. https://www.theculinarypro.com/brining-curing-and-smoking/
7. https://driedfishmatters.org/pub/dried-fish-in-west-bengal-india-scoping-report.html
8. https://www.fao.org/family-farming/detail/en/c/1680640/
9. https://www.fao.org/4/i0433e/I0433E04.htm
10. https://agritech.tnau.ac.in/fishery/fish_processtech_processing_drying.html