Food writers describe it as a delicacy on the order of foie gras; bloggers praise it as a life-changing experience, and restaurant critics all have their favorite haunts in Shanghai for the city’s signature crustacean: hairy crab. Gray-green, fist-sized, its legs spiked with bristles, it is in season only from September until November, and diners may pay $45 for a good-sized specimen said to be from Yang Cheng Lake in Jiangsu Province, the crab-equivalent of the Champagne district.

 But is hairy crab all it’s cracked up to be? My companions and I were stoked when we hit Wang Bao He last November. Known for its crab-fests, the centuries-old restaurant is a series of intimate dining rooms buzzing that night with Asian diners — a good sign, we thought.

Menus were in Chinese with photos subtitled in surreal English, but my friends, Terry Acree, a professor of flavor chemistry at Cornell, and Janelle Bloss, a graduate student studying Chinese in Nanjing, interrogated our waitress to make sure we ordered the don’t-miss crab dishes. We also asked for Shaoxing-style “yellow” wine, the traditional accompaniment.

Presented live, our hairies were bound with reedlike material and resembled rocks in a Zen garden. When they returned, steaming and pink, we decided that they might have been more appealing if they had experienced Zen purity somewhere along the way. “The smell,” said Terry, “is like dirty river water.” Under the carapaces lurked gelatinous black deposits; instead of sweet meat, we discovered stringy, bland flesh.

The off-odor was less prominent when we bathed bits in the sauce of rice vinegar with ginger, “which would make anything palatable,” as Terry observed. But the wine, served in a metal cruet, added another unpleasant note; dry and acidic, it recalled a hyper-oxidized, bitter Marsala,

Other choices, including a crab and tofu dish, proved disappointing. In the end, only the roe delivered a savory marine taste. Not much satisfaction for the $140 we’d paid for a four-course shared meal, including the wine and three beers.

But the bust was probably less about Wang Bao He than about the hairy crab market itself, which (like much of China’s food supply) is vulnerable to pollutants and counterfeiters. Hard times for the hairy crab, then, and for travelers like the Korean couple next to us.

As Terry, Janelle and I chatted about our malodorous meal, I noticed our neighbors sitting with a pile of crab carcasses, picking their teeth unhappily. On their table was a guidebook with a Shanghai scene on the cover. “I know what they’re thinking,” I said. “’Is it just us?’”

Wang Bao He, Fuzhou Lu 603, Shanghai, (86-21) 6322-3673