Each autumn, the restaurants of Shanghai are overrun by large hairy crustaceans. Market stalls pop-up all over the place packed with the creatures, their legs and pincers bound up in string, and everyone goes crab crazy.
When they’re in season, the Chinese mitten crab is a delicacy that those who can afford it will gorge themselves silly on at every opportunity. And the Chinese love affair with the mitten crab dates back centuries. Li Yu, the seventeenth-century playwright, was so enraptured by these creatures that he penned a charming if obsessive paean:
“While my heart lusts after them and my mouth enjoys their delectable taste (and in my whole life there has not been a single day when I have forgotten them), I can’t even begin to describe or make clear why I love them, why I adore their sweet taste, and why I can never forget them… Dear crab, dear crab, you and I, are we to be lifelong companions?”
The crab takes its name from its large hairy claws – it looks like its wearing furry mittens. Roughly twice the size of the palm of your hand, the crabs live in freshwater, but need to get to saltwater to reproduce. The best crabs are those from the Yangcheng Lake, about 80 kilometres west of Shanghai, which are harvested by fishermen as they try to make their way to the Yangtze River to breed. The females come into season in the ninth month of the Chinese lunar calendar and the males in the tenth month, and from then on – from October to December – you can’t move for the hairy critters.
Although the crabs are native to Asia, they have been spotted as far afield as California, emerging from the River Thames in London and merrily going about their business in the River Clyde in Scotland. In Europe and North America, these hairy monsters are nothing less than an invasive species, purposefully marching up riverbeds, taking over local waterways and wrecking flood defences and embankments by burrowing holes.
Aficionados of crab season opt for simplicity in cooking to allow the succulent, delicate flavour of the crab to win out over more elaborate and overpowering sauces. According to traditional Chinese medicine, crabs are considered a ‘cold’ or yin food and should not be eaten with other ‘cold’ food. Instead, it is usually served with ‘hot’ huangjiu (Chinese yellow wine) or ginger tea, or a dipping sauce made of vinegar, shredded ginger, red sugar and soy sauce, all ‘hot’ or ‘yang’ ingredients.
Whether or not you subscribe to this concept of hot and cold, the crabs themselves can appear rather daunting to a first-timer. Tear open the front of a crab and you’re faced with a (delicious) gloopy roe the colour and consistency of runny egg yolk, with the fatty richness of foie gras. This is the prize, but after the roe has been devoured, the legs can be cleared of their silky smooth white flesh that must be picked out with a single-minded focus. The lungs, stomach and little grey rubbery heart, however, should be discarded.
Ritual is a very important part of the whole crab guzzling process. Given the nature of the crustaceans, getting into them and savouring the meat and roe takes time, forcing often hurried eaters to slow down and enjoy a leisurely dining experience with friends or family that can take several hours.
All of this pleasure comes at a price: hairy crabs can cost more than US$100 per kilogram and the majority are consumed in the wealthy areas of Shanghai and Hong Kong. The Chinese love them so much that they have also been sold from vending machines, stored at 5°C to induce a sleepy state in the crab. But beware: there have been reports of fake hairy crabs being passed off as the real thing.