It has been said that the only thing the Chinese will not eat is "..the oink of a pig and the hiss of a snake.." This unique ingredient is testimony to that somewhat languid phrase.

The bird's nest described here is that of several species of cave-dwelling swallows that are found in coastal areas in Southern China. Unlike most bird nests, which are fashioned from twigs, feathers and leaves, these remarkable birds construct their nest with their own saliva.

The swallows have a diet high in seaweed and this leaves a gelatinous nature to the bird's spittle, which enables them to make nests this way. The sticky texture of the nests allows the birds to place them high up in caves where the young are incubated and hatched. Now this is where it gets tricky. To harvest the bird's nests, workers need to climb rickety bamboo ladders to heights in excess of 60 metres (200 feet). It is a seriously risky job. The danger involved in harvesting and the scarcity of the nests themselves forces the price to astronomical levels. Be prepared to pay over 200 dollars for a top specimen.

There are two types of bird's nests, black and white, which are constructed by different species of swallows. The white nests are the most prized, as they contain almost pure saliva. The black nests contain debris such as twigs and feathers, which must be cleaned and can taint the final product.

You may be wondering what happens to the bird's breeding cycle if all the nests are being plucked away. Apparently there is strict regulation regarding nest harvesting, with two defined harvest periods. The first is before the birds lay, requiring the poor devils to build another nest. The second is after the chicks have left the nest. I prefer to take Chinese regulation with a grain of salt and hence do not eat bird's nest.

So why all the fuss over what is essentially bird spit? Well, unsurprisingly the Chinese consider the nests a tonic (read: Viagra). But more importantly, the gelatinous texture of the nests is highly prized by Chinese gourmets. Most food in the West is rated by taste and aroma, with texture coming a distant third. To the Chinese, texture, or rather contrasts thereof are just as important.

The nest is almost always made into a soup with garnishes of minced chicken or ham and eggs, usually quail. Sometimes it is served as a sweet soup, flavoured with yellow rock sugar.

There is a less costly and more humane version called mock bird's nest soup. It contains agar-agar and fish maw (let's just call it fish stomach and leave it at that)

How to prepare bird's nest

If you find yourself in possession of a bird's nest, here is how to clean it for soup. Cover the nest with cold water overnight. The next day, rub the nest with vegetable oil, and then cover again with water. Continue until no more debris rises from the nest.

Add the nest to simmering chicken broth and cook until the nest falls apart and is gelatinous in the soup. Stir the minced chicken into the soup and cook through. Add some hard-boiled and halved quail eggs. Season with some soy sauce, salt and a little sugar. Serve immediately.