Shoryu Ramen 3 Denman St, London W1 (no booking). Meal for two £30. Sasuke 32 Great Windmill Street, London W1 (no booking). Meal for two £40. Ippudo London Central Saint Giles, London WC2 (no booking). Meal for two £30-£90.

A few weeks ago I was approached by representatives of Ippudo, a Japanese chain of ramen restaurants which was preparing its London launch. Would I, for a fee, host their opening party? Er no, taking money to promote restaurants really isn’t part of the job description. Still, I could understand them examining all the PR possibilities. Ippudo may be a highly regarded brand in Japan, with 85 branches. They may be famed for serving noodles in half a dozen different textures from soft to very hard. Its founder, Shigemi Kawahara, might be the self-styled Ramen King.

But in London they’re just another place selling noodles in soup. Here, new ramen restaurants are stacking up like jets over Heathrow. Early entrants like Bone Daddies and Tonkotsu – the latter specialising in a broth of the same name made from an 18-hour simmer of piggy bones to produce a liquor of ludicrous meatiness – now find themselves in a market almost as crowded as the Northern Line on a Monday morning.

Today, every third shop front in London’s Soho seems to be knocking out ramen. It has led to the worst outbreak of food geekery since the dirty hamburger wars of 2011. There are mutterings about noodle strengths, and the mammarian wobble of one soft-boiled egg over another. Rumours are rife about places flying their tonkotsu broth into the country as concentrate. Oh, the shame. The problem is that, as with so much in Japanese culture, once you get past a certain quality threshold it’s very hard to distinguish one thing from another. You’re in dog-whistle territory. Around 98% of the population will shrug and go: “Yeah, it’s a bowl of noodles in broth.” The other annoying 2% will perv endlessly over the details.

I decide to try life as a details perv. For example, I hear great things about the chashu pork – a braised round of pork belly –at Sasuke on Great Windmill Street in Soho and conclude I have to go. There are white walls, wooden tables and bored-looking Japanese waitresses.

By contrast the spicy miso chashu ramen is a vivid flash of colour. The broth is a lovely shade of rust with a chilli kick. There is the lawn green of finely sliced spring onions, and a dribble of chilli sauce across the slices of pork. The meat is soft, the fat beginning to melt away into the fiery liquor. At £12.90 a bowl, it’s at the expensive end especially if you add a soft boiled egg for £1.50. Over £15 including service for ramen is going it some. But Sasuke has the virtue of peacefulness.

And being open. Newcomer Kanada-Ya is another whitewashed import from Japan which has set up just behind Tottenham Court Road. The first lunchtime I visit it’s closed, the chairs stacked on the tables like it’s going-home time at infant school. The manager tells me they ran out of tonkotsu broth the night before. They won’t have more until that evening. I express bafflement. A ramen place? Running out of broth? That’s like a priest running out of prayers. Two days later and they are closed again. They have a Japanese TV crew in making a film about the ramen invasion of London. I cross the road to Ippudo, located directly opposite.

Where Sasuke and Kanada-Ya are all stripped-back minimalism, Ippudo, in a shiny glass and steel development, is ramen restaurant as nightclub. There’s a bar and shiny surfaces. And lots of staff shouting greetings in Japanese – even the European ones. It has only been open a day, but it appears every Japanese expat in London has found their way here. They don’t take bookings and the queue is already an hour long, by which time they will be closed, they say. They may have tried to buy my arse for the opening party, but they clearly haven’t a clue who I am, which is refreshing.

I return a few days later. Now the queue is 45 minutes so we go to the bar, where we order drinks and some bright, crisp cucumber in spicy sesame sauce and run up a £20 bill. After 40 minutes we check on our table. They flick through the list of names on their iPad. Oh dear. They’ve given our table away to someone else; the endless joys of non-reservation restaurants. Charmed I’m sure.

Finally we get to sit down and most of the food is great. We love the stretched-out chicken wings, like dinosaur claws, in punchy black pepper sauce. We like the silky cases on the pork and vegetable dumplings. The seared pork belly inside soft rice buns is a powerful kick of flavour, even if the bun itself is a little dense.

As to the ramen, the tonkotsu stock here is a fine example: meaty and rich, with a sticky gelatine echo of the bones that went into it. The noodles, which we order with regular softness, come with a lovely bite. But then, given Ippudo’s global reputation, this is as it should be. I don’t think it’s especially better than the home-grown Tonkotsu chain. And the service is bloody annoying. I long for peace and quiet. Music throbs and we are asked every two minutes how we are. Yes, it’s all fine. Now leave us alone. Plus, there’s the bill. Because of the long wait, and with sides and wines from a tiny list, we hand over £100 for two. For ramen.

And so to my top tip. When we were turned away from Ippudo we went to one of the growing chain of Shoryu Ramen, a business that grew out of the Japan Centre. Some are sit-down restaurants of varnished wood; others are mere takeaways with a counter in the window. At one of the latter, on Denman Street, we’re given a very serviceable tonkotsu broth with respectable noodles. And it costs just £7.60. What’s more, it comes bloody fast. The pork-belly buns are some of the best I’ve tried in London. So that’s the one to which I’d return.

Of course ramen is about nuance. Of course attention to detail is important. But the fact remains that it’s still casual food. The ramen pervs can continue perving. The rest of us can happily grab a quick bowl of noodles in broth.

Jay’s news bites

■ Those wishing to embed themselves in another distinct part of Japanese culinary culture should try Koya (and its younger sibling Koya Bar, next door), also in London’s Soho. Both go the way of the noodle, in particular the thick wheat flour variety known as udon. You can have hot udon in hot broth and cold udon in hot broth, cold udon with cold sauce to dip or pour, and so on. People who know about these things describe the two Koyas as very much a slice of Tokyo in the capital (koya.co.uk).

■ The Food Chain, a brilliant charity providing nutritional advice and support to people with HIV – full disclosure; I’m a patron – is holding a fundraising night on 6 November at London’s Foundling Museum. There’s music, entertainment, killer food and a cracking auction (foodchain.org.uk).

■ A newly released report into Britain’s restaurant sector from The Caterer, the leading magazine of the hospitality business, reveals the casual dining market has seen the greatest expansion since 2009, up 11.9%. Altogether, eating out sales are up 2% since 2013 (thecaterer.com).

Email Jay at jay.rayner@observer.co.uk. Follow Jay on Twitter @jayrayner1