Chicken only became a staple food in much of Asia in recent decades, and there was even a time when Chinese people considered eggs as a useless by-product of raising chickens, resulting in a roaring trade of tinned eggs from Shanghai to the UK and continental Europe.
Boatload of 150 baskets of eggs on Soochow creek, Shanghai, China. Photo: Wikimedia Commons (Unknown photographer)
Egg consumption per capita in China was less than 2 kg in 1963 and reached 20 kg in 2016, according to Helgi Library, and Statista notes that in 2019, China dominated egg production at just over 660 billions eggs produced.
If we go back in history, Jason Wordie describes an interesting situation in China, which he writes about in the South China Morning Post (SCMP).
He describes the egg export industry from Shanghai just before 1949, in the words of Dr Gren Wedderburn’s memoir No Lotus Garden: A Scottish Surgeon in China and Japan (1979): “Although chicken is an important dish, by quirk of culinary aberration the Chinese neither value nor prize the humble egg. Before the turn of the century, some astute foreigner realised this and over the years built up an enormous business.”
He continued to write that as long as there was water transport and collecting depots, “small farmers and peasants were only too willing to be paid for a commodity for which there was little demand,” adding that “the peasant’s wife, by selling a few eggs, gained a copper or two for what was barely a useful item.”
A million sources of eggs
According to Wedderburn, the eggs were delivered from a million sources, preserved in ice as soon as they reached a small depot, collected on junks and sampans to be taken downriver to a factory in Shanghai. “The eggs could only be sufficiently fresh and in commercial quantity if the collecting system cast an enormous net into the hinterland with a widespread batch of agents,” wrote Wedderburn.
In the Shanghai factory, scores of girls sat at tables where the eggs came past on a moving belt. Each girl took an egg, broke it on a prong, smelt it to make sure it was fresh and if so, emptied the contents into a 15-litre tin, and if the egg was bad, she would throw it behind her into a refuse trough.
The result: billions of eggs
“When one considered that, pre-war, there were special refrigerated ocean-going freighters whose only cargo out of China to Europe consisted of tins of eggs, it will be realised that literally billions of eggs arrived in Shanghai. Eggs and egg powder used in baking in Europe depended almost entirely on this source.” From the late 1940s, Hong Kong also exported egg products, in particular salted and preserved eggs essential to various Chinese recipes. While most of these items consumed in Hong Kong – then and now – were produced in mainland China, a thriving local production sector almost entirely devoted to the North American export trade also existed.
During the years of United Nations embargo on China trade, invoked at the outset of the Korean war in 1950, only preserved eggs produced in Hong Kong could be exported to the US. In Chinatowns from San Francisco to New York, preserved eggs were produced in Hong Kong, from eggs that were certified to having been laid by Free World poultry.
Preserved, thousand-year-old eggs
SCMP’s Susan Jung, a trained pastry chef, describes preserved eggs (pei daan, also known as thousand-year-old eggs) are aged for about 100 days after being cured in a mixture of earth, ash, slaked lime and tea.
Pei daan and another type of preserved egg, haam daan (salted egg), are unique to Chinese cuisine. Pei daan are sold coated in a beige or sandy-coloured clay and rice husks, while haam daan are coated in black, charcoal-like ash. They are either duck or chicken eggs.
Pei daan can be eaten raw and is usually served with soy sauce, sesame oil or sliced pickled ginger. Haam daan must be cooked before eating.
Most of the salt is concentrated in the white, which some people discard, preferring the yolk.