Never has so much fuss been made and nonsense talked than about martinis. At least one person in a party of drinkers will always have firm views on the quantity of vermouth, whether gin or vodka should be used – and then – the type of gin or vodka. To arm yourself for such a conversation, read my guide below, reviewing six of the best hotel bar martinis in London, and also how to make the perfect martini.

I was pleased to find that nearly all the bars I visited retained Italian barman, something I thought would be lost. They are incredibly knowledgeable and always have time for you. They also know each other and whether in their 20s or 70s they all seem to have an Ollie Reed story, some of which are probably true.

The top six hotel bars

Dorchester Bar, The Dorchester – best all-rounder

This has only recently reopened and is now a sophisticated but immensely approachable bar just off the lobby. There is no snootiness from staff, the place is comfortable and bright and the new design incorporates high backed aubergine banquettes, with spears of red glass at their rear, mirrored glass tables and lacquered mahogany walls. It isn’t too big and caters for a mixed crowd of workers and residents. The Dorchester also had the best and most succulent range of nibbles among all the bars including juicy Wagyu beef, langoustine tempura, Thai fishcakes and tartines made on Poilâne bread.

This is the 75th anniversary of The Dorchester and they have gone back to the original recipes of Harry Craddock, first head barman here in the 1930s. They have gone back even further with the gins and recreated their own Dorchester gin, called Old Tom, from an early 18th-century recipe – sadly this has proved such a huge success that they had run out on my visit.

Simon, the erudite assistant manager, is passionate about martinis and introduced me to The Genesis of the Martini (£14), a flight of three dinky glasses resting in ice following the evolution of this cocktail. The first glass is an early contender called the Martinez (a mix of Old Tom – substituted on my night – Punt e Mes, Maraschino and orange bitters) that was quite woody but sweet. The second glass is the Original Dry Martini which is a 50/50 gin/vermouth mix is far too herby for me but was popular after the First World War and my friend loved it. The vermouth content began to decline after the Second World War to the few drops we have in martinis today and that is my third glass. Who would have thought that drinking could be so historic?

The Dorchester, Park Lane (020 7629 8888, www.thedorchester.com)

The Library, Lanesborough Hotel – best for cigars

Surprisingly the Lanesborough’s intimate bar has fake books which my friend Shyboots, a rather forthright interior design guru, was having no truck with. She was also very firm that she should have vodka and if I must have gin, she sneered, it should be Tanqueray 10. See what I mean about blinkers?

Allegedly Abramovich and mates haunt this bar with American suits puffing fat Cuban cigars – the cigar menu is impressive even if it all ends up in smoke. My attention gravitates towards an attractive woman eating one peanut at a time for 40 minutes until her Russian beau arrives. The surroundings are plush, it is the most comfortable of any bar you could visit. Thick carpets, easy chairs, sofas – you sink into this bar. The head barman is the ultra genial Giuseppe from Puglia who is collecting cognacs for the bar to compose a “a liquid history” - a 1786 cognac costs £2000 a shot.

Maybe it was the fake books, £500 cigars and cognac collection but I get the feeling that martinis (£12.50) are not the priority either with drinkers or the bar. They do their best and that’s pretty good - you won’t get many nicer than Giuseppe - but The Library seems more fitting for an after-dinner cognac.

The Lanesborough, Hyde Park Corner (020 7259 5599, www.starwoodhotels.com)

The Egerton – best undiscovered bar

Who knows about this hotel? Few. It’s got a loyal American following but it remains a little Knightsbridge secret of only 30 rooms. The bar is the smallest of all the ones reviewed and because of its secrecy it is discreet for famous shoppers from nearby Harrods. Old cartoons decorate the walls and the seats are comfy, with two high stools for the bar. Adjoining the bar is a sitting room for the overspill. I didn’t have the heart to ask Antonio how old he is, but I realise that like all good barmen he is too old to retire now. Old school, with the manners of a gentleman, he can recall to you all the famous people he’s served or his childhood in Sicily. Having worked at Duke’s his martini (£14) is similarly prepared: superlativo!

Egerton House Hotel, Egerton Terrace, Knightsbridge (020 7589 2412, www.egertonhousehotel.co.uk)

Claridge’s – quietest bar

The most subdued of hotel bars – it was midweek. Designed by David Collins, the bar still keeps its original Art Deco features but he’s added a silver leaf ceiling, green glass chandelier and red leather bar stools and banquettes. Towards the back the Snuggery seats about 20 in some privacy. This all sounds delightful but the overwhelming colour, due to the subdued lighting, is beige. Still, on the evening I visit it oozes class. There is a sort of quiet, easy-going calm that makes this the perfect venue for a de-stressing after-work martini (£10.75) or a good bitch about office co-workers. Sadly I’m not asked what gin I want and the glass doesn’t look chilled. It’s a fine, workaday cocktail but it isn’t an event, and every martini should be an event.

Claridge's, 49 Brook Street, Mayfair (020 7629 8860, www.claridges.co.uk)

Duke’s Hotel Bar – most intimate bar

Duke’s is in a courtyard, off a lane off St James – thus having all the requisite distinction and discretion. This is where James Bond’s phrase “shaken not stirred” originates. According to the British Medical Journal (December 1999) martini is better for you if shaken than stirred because of the "facile oxidation of reactive martini components”. Whatever. But James Bond favoured vodka so that doesn’t count in this and none of the six gin martinis are shaken or stirred, just poured. The bar is arranged in chunks, having been extended by add-ons over decades. You enter to see a few tables in front, turn left to see another room and the bar, and behind the bar is the normally deserted smoke-free room. It is inhabited by a clutch of mostly non-resident drinkers, half of which are American.

Sadly, Tony Michelotta - the legendary head barman - is away but his team of Angelo and Giovanni look after us (my friend Mappy and me) very well. A tray is brought to our table with bottles of ice cold vermouth and gin and a Sicilian organic lemon unwaxed. Giovanni puts the drops of vermouth in followed by the gin and then he doesn’t twist but subtly squeezes a peel of lemon so that it’s juices spray out onto the martini surface. Then he rubs the peel around the rim and lets it subside in the glass. After three-quarters of a glass Mappy - although Australian - said she had had enough, beaming in a lopsided manner. In fact they won’t serve you more than two martinis at the Duke’s, which is just as well. The Duke of Wellington stares down from a canvas thinking me rather effete. I imagine the concept of metrosexual’s quaffing cocktails was an abomination in his moral universe. The martini is £14.

Duke’s Hotel, 35 St James’s Place, Mayfair (020 7491 4840, www.dukeshotel.com)

The Blue Bar, The Berkeley – funkiest bar

This is the only bar to have someone on the door, even though the entrance is from the lobby. That was a bit strange but the idea is to keep the noise out of the lobby. Music crashes your senses as you enter. Not so loud you can’t hear but loud enough that you have to huddle. It is another David Collins designed bar and the blue is a greyey-blue (called Lutyen’s Blue) with lots of sparkle from cabinets of cigars and an onyx bar. The floor black crocodile print leather.

It’s a regular haunt of nearby workers (aged 20s to 40s in arty jobs) and cocktails are the big thing. Three double shots per glass. So a very big thing. The second big thing is champagne; the delightfully nutty Krug (£92 per half bottle) is popular with a straw. Obviously a martini is going to be different here. So when the bar manager Adam got out his atomiser I wasn’t sure what to expect but that’s the way they add the vermouth here. People want it dry so the barmen can be seen spraying all evening like divas with a bad throat. Adam also delivers a flight of gins, little tasting glasses with a half mouthful of three different gins (Bombay, Tanqueray 10 and Miller’s Westbourne). I choose the latter and have a very good martini (£11).

The Berkeley, Wilton Place, Knightsbridge (020 7235 6000, www.the-berkeley.co.uk)

Which gin?

Bombay Sapphire, Millers Westbourne and Tanqueray 10 (47.3 per cent alcohol) are the main gin brands and they all have their virtues, but very few barman ask which you prefer. Almost certainly you will prefer one gin more than another so if you don’t know already they should be glad to let you try a teaspoon of each in a glass - not too cold though or you won't taste anything. Some bars offer a 'flight' - a sample of all three.

Tanqueray 10 uses fresh (as opposed to dry) ingredients – called botanicals - to flavour the gin. Juniper berries, angelica root and coriander are included. The result is a nice citrusy smoothness. The original Tanqueray (43.1 per cent) is fractionally less smooth.

Martin Miller makes two gins - Martin Miller (40 per cent) and Martin Miller Westbourne Strength (45.2 per cent) - both using soft Icelandic water. The flavour and smell is the most aromatic of all gins that I’ve tasted which isn’t surprising since they use Tuscan juniper berries, cassia bark, angelica, Florentine orris, liquorice root and coriander, Seville citrus peel, ground nutmeg and cinnamon bark. In a blind tasting (admittedly based on the opinion poll of two) the Westbourne won hands down.

Bombay Sapphire (40 per cent) contains a mix of almonds, Spanish lemons, Chinese liquorice, Italian juniper berries, orris root, cinnamon bark, coriander, angelica and cubeb berries from Java which add a mentholly heat. These dried ingredients are placed in the still with the alcohol vapour rising through them producing a fine smoothness.

How to serve it

The glass should be chilled as is the vermouth and gin. How much vermouth? The barman should ask, and purists will suggest he should also ask whether you’ve eaten. Very dry means less vermouth. On an empty stomach (you should at least have a nibble) more vermouth will soften the blow. It will be added first and will mostly remain in the bottom. The gin is poured in. The lemon peel can be sprung to release its oil on the surface (see Duke’s for the best example) or it will grease the rim of the glass and then be popped in.

The first sip - frosty cold and refreshing - gives way to greater depth and as the glass and gin warms it releases the aromatics aided by the herbiness of the vermouth to give a wonderful warm finish. In theory.

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