Hype is a vital pivot of the restaurant scene. I wish I could reveal something more wholesome, but hype will put more bums on seats and napkins in laps than a new opening’s deft seasoning or fancy produce suppliers. At the all-new, 250-seater Din Tai Fung in London’s Covent Garden, those shadowy voices of hype said we should expect an opening-week queue of five hours. In December, on a busy, pre-Christmas tourist thoroughfare, bring a cagoule and stay hydrated, because the queue for its xiao long bao and salted egg custard lava buns will feel like the sort of war of attrition from which Stephen King could milk 500 pages.

Hype of the level surrounding Din Tai Fung, I must stress, is not created simply by paid public relations teams. Clearly they help, but real, giddy hype will always be something of a perfect storm. Din Tai Fung is a global chain that specialises in Taiwanese dumplings and Huaiyang cuisine. The company has made moves on London in a swaggering – albeit politely swaggering – manner by commandeering two enormo-restaurants in the eye-wateringly expensive real-estate zones of Henrietta Street and, soon, Oxford Street’s Centre Point. What’s less easy to decipher is why Din Tai Fung is “cool right now”, which would require a spider-chart with quantitative variables on youth trends, shifting demographics, plus some lemming-attracting pixie dust.

On opening week, I got a table by being incredibly un-British and stalking past the queue, repeating, “Excuse me, excuse me”, in a purposeful, diligent manner that suggested I really should be inside the building. It’s a trick that can go two ways: you can either eat early or you can be taken down like a tighthead prop in a vicious dump tackle. This time, I was lucky.

Pork xiao long bao, Din Tai Fung Restaurant, Covent Garden, London.

Din Tai Fung’s pork xiao long bao: ‘Pleasantly inoffensive.’ Photograph: Karen Robinson for the Guardian

Din Tai Fung’s decor will divide diners. You will either revel in its sparse, non-luxurious simplicity, the cheap tables, the Ikea glasses and the hollow acoustics. Or you may feel as if you’re in the dining room of a last-minute two-star Costa Brava hotel that you booked half-board but by day three are loth to eat in. The path to your table takes you past a glass-fronted workspace filled with dumpling technicians, all wearing surgical masks and white laboratory coats, standing in groups of five, and filling, weighing and primping xiao long bao, shumai, jiaozi and so on. Sporadically, one of these white-coated, faceless and almost inaudible workers will totter, Pingu-style, to your table laden with a stack of baskets. This is either charming, or a bit like feeding time at a medical trials centre you signed up for to settle your gambling debts.

We ordered the classic pork bao, in delicate, accomplished, neatly pinched dough with 18 tiny puckers. To taste, they’re pleasantly inoffensive, neither obscenely soupy nor intensely flavoured. We took the pale green, vegetarian jiaozi, which are pretty to look at and filled with brown, umami-flavoured mulch. A side of black, waxy, soy-drenched wood-ear mushrooms with ginger in vinegar were peculiar yet compelling.

We wanted the prawn and angled gourd, but there was none. We wanted crispy wonton, but there was none of that, either. Almost everything fried on the menu was unavailable, as were all the desserts – the sweet steamed buns filled with red taro or chocolate lava, or any of the jellies, rice or mango puddings. This, I mused, might be a handy thing for one of the managers, of which there are about 17, to go and tell the people queueing for five hours outside.

Din Tai Fung Restaurant, Covent Garden, London

Din Tai Fung, London WC2: ‘Dumpling technicians in surgical masks and white lab coats.’ Photograph: Karen Robinson for the Guardian

Here is the rub about hype: there would be nothing at all wrong with Din Tai Fung if you popped in one day, unbesmirched by pre-bluster and expecting nothing. In that case, you’d slurp the dumplings, make a crisp, delicious golden prawn pancake disappear and perhaps a bowl of wobbly wontons in chilli oil, maybe even some bland, white noodles in a puddle of spicy sauce, and leave feeling pleasantly sated. You would observe the aesthetically splendid bowl of prawn and egg fried rice with some gratitude for your lot as a fed, watered, sheltered human being. But, no, you were caught up in hype, so now you can’t accept anything less than being shot in a rocket to the Cantina bar in Star Wars, where the dumplings are served by magical unicorns that lick the oldness off your face between plates, leaving you more youthful by the time the bill arrives. Anything less than that is a letdown.

I will return for my pudding when the hype fades, the influencers get bored and the buzz moves on in no more than 12 weeks. Trends come and go, but fickleness never goes out of fashion.

Din Tai Fung 5-6 Henrietta Street, London WC2, 020-3034 3888. Open all week, 11am-10.30pm (10pm Sun). About £30 a head, plus drinks and service.

Food 4/10
Atmosphere 5/10
Service 6/10