Natural vs Fake Birds Spit Soup

Some retailers have been trying to sell fake nest by using all methods to maximize their profit. Few years ago, there were rubber and pig skin nest. Recently, there is coloured and glued-nest. Some people even use strips of seaweed/coral and grass nest to sell in the form of whole Birds Spit Soup and biscuits.

Natural vs Fake Birds Spit Soup

1. Colouring:

In coloured or red cave nest, usually low cost house nest is used and is coloured to yellow or red then it is sold as high priced red cave nest or brown cave nest. It is hard to detect this fake nest’s authenticity before immersing in water. When it is immersed in water, red or yellow colouring will appear in water. It will also become soft and semi-transparent. In natural cave or house nest, its colour is natural, therefore even with water immersion and cooking, the colour will not fade or change. A cave nest needs at least 5 hours of cooking time before it is edible. Such a ‘hard’ food, how is this suitable for the elderly? Unlike cave nest, house nest only requires 45 minutes to 1 hour of cooking time and is appropriate for people of all ages.

2. Glued-nest:

It is often seen in whole Birds Spit Soup. Flour, rubber, glue or other adhesives are added onto the surface of low-grade whole Birds Spit Soup to enhance the appearance of the nest, which also increase the weight up to 30% and makes the nest hard to break. Therefore, consumers who are unaware, not only consume these additives, but also need to pay extra 30% of money.
To differentiate between the natural cave nest from the fake nest, It is stated by professional that a natural cave nest has uneven colour. Colour appeared on a raw nest, will be a mixture of yellow, red and white. The coloured part is formed by the mixture of minerals and swiftlet’s protein content in the saliva. Mineral content will not be distributed evenly on each strain of Birds Spit Soup while the colour is spread evenly in a fake nest. Only cave nest comes with darker colour while house nest is white in colour.

Introduction to Birds Spit Soups

Birds Spit Soup comes from the saliva of swallows. Basically they are made of the saliva of Apodidae swiftlet and the other swiftlet under the same type. In brief, there are around 90 types of swallows and not all swallow saliva is edible. Those swallows that often bring branches, straw and soil to build nests which are definitely not edible. Edible nests are made of saliva of swiftlet, Feather Prime swiflet or Grass swiflet.

Classification

Birds Spit Soups are divided into the two following major categories:
(1) House Nest
​Swallow builds nest inside a house called swiftlet. House roof is made of wood. The internal setting of the house imitates the temperature, luminosity and humidity of natural caves. Average temperature is 28°C to 30°C and humidity lies between 89% and 90%, environment is humid and dark. Swallows leave the swiftler house in the morning to look for food outside until evening. Since environment is ideal, there is little impurities and feathers in the Birds Spit Soup and it is cleaner with more complete shape like a boat or a spoon. According to swiftlets´ color they can be divided into white, yellow and red (blood). White nests are softer and smoother while golden nests and red (blood) nests are crispier in texture.
New Knowledge of the Red (Blood) & Yellow Birds Spit Soups before purchase
Up to now, there are many controversies over the formation of the Red (Blood) Birds Spit Soup. It is believed that the formation of the Red (Blood) Birds Spit Soup is because the swallows have consumed several kinds of food. There are different arguments in academia whether this is due to the enzyme of the food, bacteria of the food, chemical reaction or heat in the food. It is also believed that if the swallows´ feces are collected from the swiftlet house and placed next to the Birds Spit Soup for a week (during that the Birds Spit Soup will be stored in plastic container and separated from the swallows´ feces by the gauze) can also formulate the Red´s nest. We have consulted many industry practitioners and believed that over 90% of Red (Blood) Birds Spit Soup sold in the market (including us) are formatted based on the latter rationale.
The process of the color formulation of Red (Blood) Birds Spit Soup: Birds Spit Soup will turn white color into yellow color. Then, yellow Birds Spit Soups turn into orange and finally into red (blood Birds Spit Soup). The content of nitrite in yellow Birds Spit Soups will be higher than white Birds Spit Soups, but lower than red (blood) Birds Spit Soups.
Supplementary
Above result is the average amount based on the testing of the mixture of our few selected piece of red (blood) Birds Spit Soup products which are blended together. The content of the nitrite in red (blood) Birds Spit Soup of each piece will be varied from 1000ppm to 10000ppm etc.
Acceptable daily intake (ADI) of nitrite is 0.07mg per 1kg body weight. For instance, a 60kg adult will exceed his ADI of nitrite only if one consumes 125g dried red (blood) Birds Spit Soups a day. In other words, it means that only if consuming at least 16 pieces of red (blood) Birds Spit Soups a day will an adult exceed the standard, assuming the weight of 1 piece equal to 0.2 tael (7.56g).
Since the content of nitrite in Birds Spit Soups is not listed in Hong Kong regulations, we list out the content of nitrite in meat products here for reference.
Remarks：
1. Source: Preservatives in Food Regulation (Cap. 132BD), Schedule 1
2. 1 ppm=1/1,000,000； Example：1 ppm means there is 1 mg of nitrite in 1 kg of Birds Spit Soups
(2) Cave Nest:
Swallows build their nests on mountain caves, rock caves and cliffs. Affected by natural climate and environment, the texture tends to be stiffer and harder, with a darker color and less appealing appearance. There are more impurities in cave nest and it takes longer time to soak, giving a crispier texture.

Varieties
Birds Spit Soups sold on the market include natural Birds Spit Soup cups, strips, threads, crumbles and scattered pieces processed into cakes of different shapes. There are three major types:

Serving Methods

According to recommendations of registered nutrition therapists, to cope with human body's ability to absorb pro-active protein molecules, regular doses should be taken continuously. Here are two serving methods for better results:
(1) 1 to 2 bowls per week
(2) 1 to 2 tablespoons per day

Country of Origin

Origins of Birds Spit Soups are spread in Southeast Asia, including Indonesia, Thailand, Vietnam and Malaysia etc. Different Birds Spit Soups have different textures.
Indonesia
House nest is the most common variety in Indonesia with less impurities and cleaner. Texture is smoother and softer. Indonesia is the origin of highest production volume and supplies about 80% of Birds Spit Soup in Hong Kong.
Thailand
Thai Birds Spit Soups are thicker, higher density and firmer in texture. It takes more time in soaking and stewing. Since production volume is small, the prices are higher.
Malaysia
More Feather Prime swiflet nest products, usually swiftlet processed into cakes and prices are low. Since instant food is usually produced with Birds Spit Soup cakes, there is less and less dry Birds Spit Soup cakes sold on the market and prices are thus increasing
Vietnam
Quality is high with stronger taste and aroma after stewed as compared to others, but supply is very limited.

Harvesting Period and Grading

Usually, the harvesting period of Birds Spit Soup is separated into several months between the harvesting periods. The nests built during the first period, which is from November to March every year, are called the first-tier nests. The second period and third period follow.
1st tier
Nov-Mar
With surplus rainfall, reproduction is promoted in small animals. Aerodramus therefore gets sufficient food supply and this strengthens their bodies, thus lead to increase saliva secretion. Impurities are extremely little. The nests are big and thick and volume is the largest when soaked. The 1st tier nests are the most precious.
2nd tier
Apr-Jun
The second period for building nests. The production sites start entering dry season and the source of food for Aerodramus is reduced. Nests built are looser and the threads are less closely grouped and less dense. The shape and volume after soaking is not as good as the 1st tier.
3rd tier
Jul-Oct
During the season of extreme dryness, Aerodramus are in their worst body condition. Saliva secretion is slow and feathers fall off quickly, thus impurities (such as feathers) increase. Smaller volume when soaked.

Functions

​"Ben Cao Bei Yao (Complete Essentials of the Materia Medica)" composed by Wang Ang in 1694 during the Qing Dynasty and "Ben Jing Feng Yuan (Origin of Materia Medica)" composed by Zhang Lu in 1695 have shown that centuries ago, Chinese people have already approved the effect of Birds Spit Soups and apply them in disease treatment. From then on, from 1757 to 1871, a number of scholars and experts have explained in details in "New Compilation of Materia Medica", "Ben Cao Qiu Zhen (The truth of Materia Medica)" and "Notes on Compendium of Materia Medica" the benefits of Birds Spit Soup, proving that it is a previous food with treatment effect. Among them, as in "Notes on Compendium of Materia Medica", Birds Spit Soup has "sweet taste and is mild and calm in nature, greatly boosts internal fluids and lungs, decreases phlegm and stops coughs, nourishes as well as detoxifies. Sacred medicine for treatment of tiredness and weakness".
According to an article entitled "A Study of Birds Spit Soup" by Professor Jiang Run Xiang and Mr. Guan Pei Sheng in "Ming Pao Monthly Magazine" (1985, issue 231), after thorough study, it was proved that as early as Ming Dynasty (1536), there were written records about Birds Spit Soup in Huang Zhong's "Hai Yu". In 1596, Tao Ben Jun as described Birds Spit Soup as luxurious food product in "Minzhonghai Cuoshu (the earliest diction on Marine Biology in China)". After over 100 years of consumption and clinical testing, finally a number of scholars have approved the medical treatment effect of Birds Spit Soup and instead of just another kind of food, it was considered as a precious nourishing item.
According to Professor Jiang Run Xiang, references from various times in China have proved that Birds Spit Soup heals the lungs and its effect is extremely prominent on terminal tuberculosis, stomach ulcer and coughing out blood, as well as promoting growth in human body.
In recent years, Professor Jiang has been researching and performing repeated tests on Birds Spit Soup. In experiments on cells in-vitro, Birds Spit Soup is discovered to contain mitogenic stimulation factor and Epidermal Growth Factor to stimulate cell growth and reproduction. It also promotes tissue growth in human beings, cell division and boosts cell immunity. These provide scientific evidence to prove that Birds Spit Soup promotes growth, replenishes energy, speeds up recovery of diseases and improves resistance of body against diseases. The bio-active protein molecules possessed the following three properties:
1. Promotes regeneration of epidermal tissues;
2. Improves immunity of the body generated by cells;
3. Improves resistance of the body against X-rays.
Such bio-active protein molecules are readily absorbed by human bodies and differentiate Birds Spit Soup protein from protein in other foods.
At the same time, the report also showed that the mitogenic stimulation factor in Birds Spit Soups stays active around 80°C, but is lost upon boiling. This explained why Birds Spit Soups need to be stewed over water in low heat. Birds Spit Soup can regulate hormones in human bodies, regulate body mechanism, strengthen the body, nourishes and give youthful complexion. It also provides energy to the body and promotes catabolism of fats.