All heck broke loose in China when Zhejiang’s Provincial Administration for Industry and Commerce announced at a press conference that over 30,000 blood-red bird’s nests, the rarest and most expensive kind, contained high concentrations of the carcinogen sodium nitrite—up to 350 times the legal limit. They’d all been imported from Malaysia.

“Blood nest” in Chinese. It’s red because the bird secretes blood into it, according to legend. It has great medicinal powers that run the usual gamut from curing constipation to raising libido.

In reality, well…. During breeding season, the male swiftlet, a small bird common throughout Southeast Asia, spends about 35 days constructing a nest against the wall of a cave by interweaving strands of saliva. These harden into a bowl-like structure (cubilose) with high levels of minerals, including calcium, iron, potassium, and magnesium. Most nests are whitish. Blood nests can occur when iron and other minerals in the rock are absorbed by the nest. But they’re extremely rare. Hence, the steep price. They retail for around $4 per gram (Ecns.cn), or around $1,800 per pound.

So, why not just dye them red?

The announcement and subsequent rumors about poisonous blood nests scared the bejesus out of Tongrentang Group Co., one of the largest traditional Chinese medicine retailers; it recalled all its edible bird’s nest products. Which caused an uproar. Sales of major Chinese brands plummeted. To re-inject some confidence, Zhejiang’s bureau of Industry and Commerce pressed authorities to tighten controls on cubilose products.

The cubilose industry is big business. Malaysia and Indonesia are the largest exporters. Combined, they have about 100 million producers and processors, mostly small shops.

“They’re fakes,” declared Chua Tee Yong, vice minister at the Malaysia Ministry of Agriculture, to bring some order to the chaos of rumors (Xinhua). Turns out, Malaysia’s cubilose industry doesn’t produce red cubilose because they can’t be mass produced. It produces only white ones—600 tons a year of house nests that are cultured in special concrete buildings. It also harvests about 10 tons of cave nests. Of those, only a few are naturally red.

And the tons of red cubilose on the market? They’re dyed house nests. Because of the outsized profits they generate, dying house nests has become an industry of its own. Dying takes a week or longer, involves a lot of sodium nitrite, and costs $50 to $100 per kilogram. Customers can specify if they want red, light red, or yellow. Producers offer color cards and dyed samples to facilitate the decision process.

Good for your health? Toxic and carcinogenic chemicals—hydrogen peroxide, sulfur dioxide, sulfur trioxide, and others—are used to remove the awful smell and dirty hair from the raw material, and traces of those chemicals remain in the nests. Additionally, all cubilose carry health risks, even natural red cubilose: The material contains significant levels of nitrite that can’t be removed. Some might also contain toxic minerals such as lead or mercury.

All this must have been known for a long time. You can’t keep a whole industry silent. Though they tried. This from Xinhua:

“Government and industry officials” from Malaysia held a press conference in the capital city of Hangzhou on July 26, purporting that blood-red cubilose on the Chinese market was genuine and safe as the nitrite can be removed after hours of soaking. Ironically, the government organizations and agencies these “officials” claimed to represent do not exist.

However, the poisonous blood nest scare, after the initial chaos, settled down into a low rumble. Consumer confidence had taken a hit, but blood nests have been part of Chinese cuisine for centuries and have achieved a near divine status. A handful of toxins and carcinogens aren’t going to change that. By mid September, demand had recovered (AsiaOne).

So next time you’re enjoying an $80 bowl of blood nest soup at your fave restaurant in Shanghai, just remember that one bowl alone probably won’t kill you.

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