Edible bird’s nests are among the most expensive animal products consumed by humans, with an average nest selling for $2,500 per kilo for end-consumers in Asia. The nests have been used in Chinese cooking for over 400 years, most often as bird’s nest soup. Legend has it that shipwrecked sailors scavenging for food cleaned and cooked the nests and found the resulting stew so invigorating they were able to sail home to inform the emperor of their new discovery.
The Chinese name for edible bird’s nest, ‘yàn wō,’ translates literally as ‘swiftlet nest’ (swiftlets, common to asia, are superficially similar to swallows and known for building nests of solidified saliva). The most famous use for the nests is bird’s nest soup, a delicacy in Chinese cuisine. When dissolved in water, the swiftlet nests have a gelatinous texture used for soup or sweet tong sui (a Cantonese custard).
It is mostly referred to as ‘yan wo’ unless references are made to the salty or sweet soup in Chinese cuisine. In addition to its use in soup, edible birds nest can be used as an ingredient in many other dishes, it can be cooked with rice to produce bird’s nest congee (rice porridge) or bird’s nest boiled rice, or it can be added to egg tarts and other desserts. A bird’s nest jelly can be made by placing the bird’s nest in a ceramic container with minimal water and sugar (or salt) and double steamed. Ready to eat bird’s nest jelly is available in jars as a commercial product.
The most heavily harvested nests are from the Edible-nest or White-nest Swiftlet (Aerodramus fuciphagus) and the Black-nest Swiftlet (Aerodramus maximus). Highly prizes, natural red rock nests are often only found in limestone caves in a bird nest concession island in Thailand. The white nests and the red nests are supposedly rich in nutrients, which are traditionally believed to provide health benefits, such as aiding digestion, raising libido, improving the voice, alleviating asthma, improving focus, and an overall benefit to the immune system.
Most nests are built during the breeding season by the male swiftlet over a period of 35 days. They take the shape of a shallow cup stuck to the cave wall. They are composed of interwoven strands of salivary laminae cement. They have high levels of calcium, iron, potassium, and magnesium. Edible bird’s nest has been used for hundreds or possibly even thousands of years. Despite this, scientific evidence of its efficacy is limited. The claimed health benefits such as resisting aging and improving immunity has yet to be proven.
Hong Kong and the US are the largest importers of these nests. In Hong Kong, a bowl of bird’s nest soup costs US$30 to US$100. A kilogram of white nest can cost up to US$2,000, and a kilogram of red nests can cost up to US$10,000. The white nests are commonly treated with a red pigment, but methods have been developed to determine an adulterated product. The high cost and demand has attracted counterfeiters, leading to the halt of Malaysian nest exports to China; the Malaysian government has undertaken to employ RFID technology to thwart counterfeiting by micro-chipping nests with details about harvesting, packaging and transport.
The nests were formerly harvested from caves, principally the enormous limestone caves at Gomantong and Niah in Borneo. With the escalation in demand these sources have been supplanted since the late 1990s by purpose-built nesting houses, usually reinforced concrete structures following the design of the Southeast Asian shop-house. These nesting houses are normally found in urban areas near the sea, since the birds have a propensity to flock in such places.
Nest farming has become an extraordinary industry, mainly based on a series of towns in the Indonesian Province of North Sumatra, which have been completely transformed by the activity. From there the nests are exported to the markets in Hong Kong, which has become the center of the world trade, though most of the final consumers are from mainland China. It has been estimated that the products now account for 0.5% of the Indonesian GDP, equivalent to about a quarter of the country’s fishing industry. The entire global industry is an estimated $5 billion.
The Daily Omnivore 