Nitrite is formed via the oxidation of ammonia which is catalyzed by nitrifying bacteria that is present at the swiftlet house. Many swiftlet farmers make a mistake in controlling the humidity of the swiftlet house. Generally, they use humidifier or sprayer that creates a medium for the nitrifying bacteria to live in and therefore increasing the level of nitrite. The high concentrations of nitrite that stick at the swiftlet nest make the nest become yellowish / brownish. Farmers in Kalimantan and Malaysia prevent this by harvesting the nest early, each month, they forcefully harvest the nest, and therefore the swiftlet cannot produce offspring and regenerate. They depend on swiftlet migration from Java and Sumatra, which population continue to dwindle because of macro habitat destruction by industrialization and the increasing number of car and motorcycle compared to ten years ago. This caused the swiftlet to immigrate to a better area. It is also further fueled by forest fire in Sumatra.
The swiftlet needs to produce offspring twice a year, which is in rainy season. The advantage of this is that the nest become bigger (1 kilogram of nest consist of approximately 100 nests) and the number of offspring become abundant so that in the third year, the production of the nest will be doubled. Swiftlet farmers no longer need to worry about letting the nest longer inside the house as there is a solution, the TWS (Teknik Walet Super / Super Swiftlet Technique).
TWS is a technique that can produce swiftlet nest with low level of nitrite (almost 0 ppm). This technique is a spectacular finding from 12 years of research. There is no need for complex tools or chemicals substance. This technique only use an accurate humidity conditioning which prevent formation of nitrite. Once implemented, the swiftlet nest will forever be free of nitrite and the color will still be white even if not harvested for 7 months. The country that its farmers use this technique will be the number one in the market.