Sudi Pigott gives the low-down on this most tantalising and troublesome of molluscs

Oysters have always been linked with love - according to myth, when Aphrodite, Greek goddess of love, sprang forth from the sea on an oyster shell and gave birth to Eros, the word 'aphrodisiac' was born. Roman emperors paid for them by their weight in gold, and legendary lover Casanova reputedly devoured four dozen every morning in the bath with his lady of the moment.

Today oysters are considered a great luxury. Strange to think, then, that in Dickens' time, oysters and poverty went hand in hand, and were guzzled in a vulgar pickle of throat-burning malt vinegar. It was the greedy rush to supply urban demand, which almost emptied the oyster beds and made them a rare and, consequently, more desirable commodity.

There may be many reasons for the supposed romantic properties of this most slippery of bivalves. Oysters are full of zinc, which modern medical research has linked with improving male potency - it is said to increase sperm and testosterone production. More controversially, the shape of an oyster has been likened to the shape of certain female private parts - this may or may not entice you to eat them. Romance aside, oysters are a pretty healthy option for everyone - they're a valuable source of other minerals, such as calcium and copper, and are also rich in iodine and low in cholesterol.

How to eat them
It was the legendary Auguste Escoffier, chef at the Savoy at the turn of the 20th century, who first introduced the custom of serving oysters on crushed ice as self-contained little packages with their own exquisite salty juice. In Britain, a crustacean altar loaded with oysters has now become a design and culinary signature of most of Sir Terence Conran's restaurants. My favourite and, arguably, the most glamorous remains the Oyster Bar in the beautiful tiled courtyard outside Sir Terence's flagship London restaurant Bibendum. This is also handy for a spot of retail therapy at the adjoining Conran Shop.

• Raw oysters are best served on crushed ice and seaweed, with fresh lemon juice, Tobasco or chilli sauce, or a shallot and red wine vinegar dressing (mignonette). They should be eaten on the half shell, liquid and all. The liquid has an exquisite, salty taste and is not to be missed.

• Irish chef, Richard Corrigan, of London restaurant Lindsay House, likes to serve hot oysters with a salsify and chive emulsion, or baked with cucumber and soft herbs as a Valentine's dinner canapé.

• At Loch Fyne restaurants oysters are served either straight-up on ice, with hot sausage (a traditional accompaniment among oyster fishermen from Marennes) or baked in the shell with spinach and mornay sauce for a warming winter dish. Loch Fyne restaurants have now expanded from their Scottish base to several locations in England (see below for details).

• Rick Stein advises keeping cooked oyster recipe dishes dead simple and always using the less expensive Pacific rather than Native oysters. In his Seafood Lovers' Guide (BBC Books) he suggests grilling oysters still in their top shells with most of the liquor drained off, topped with a little double cream, freshly grated parmesan, a drizzle of melted butter and black pepper.

• The Irish prefer oysters with stout, while champagne is the natural accompaniment for a seduction meal. But the best partners are crisp, dry white French wines such as Muscadet-sur-Lie and Chablis or Italian wines such as Soave or Frascati.

• Don't feel intimidated about buying oysters to enjoy at home, but always shop at a good busy fishmonger. They must always be bought live - the shells must be closed and remain closed if lightly tapped, and they should be quite heavy as they are full of liquor. Oysters can be stored for a short time in ice or a damp cloth.

• A rule of thumb is to eat oysters only in months that have an 'r' in the name - that is, during cold weather, and when the sea is coldest. In summer, as the sea warms up, they may start breeding and can be milky, fat and soft.

• But beware. Any shrivelled up or blackish oyster with suspiciously little liquor should be rejected: an oyster in its prime should have a highly visible beard and a good light brown or greyish colour with a white muscle, a good clean flavour and be firm textured, yet juicy. And if an oyster tastes bad, spit it out.

Over the page: types of oysters and where to shell out

Types of oysters
Much confusion surrounds the differences between pacific or rock oysters, and the more pricey native with its superior gourmet reputation. But the contrast is not so extreme as, say, between farmed and wild salmon, and, of course, all oysters are farmed.

Native: the native flat-shelled oyster (famously from Whitstable, Rossmore and Galway) are seasonal, and are available between September and April, (out of season they are spawning and become overly milky, calcified and not so tasty) and take longer, up to six or seven years, to reach maturity.

Pacific: more disease-resistant rock or Pacific oysters have a frillier shell, less substantial flesh, can be eaten all year round and mature in two to three years. Pacific oysters come originally from Japan, and are the most widely cultured oyster in the world. They're supposed to be creamier than the Atlantic oyster.

Open sesame!
'Pepe' Espinoza Valerio, champion oyster shucker of London restaurant and oyster bar, Green's, broke the world oyster opening record by opening 100 oysters in 7 minutes and 32 seconds - not something to attempt at home. To open oysters, he suggests:

1. Wrap a thick teacloth around your hand for protection, hold the oyster with the more rounded shell downwards to catch the juice.
2. Insert the short oyster knife just to the right of the hinge at the back of the oyster shell and wriggle the blade determinedly, yet gently, to sever the muscle which holds the shell together.
3. Then the top membrane should be cut first, leaving the oyster free from its shell, but still in place.
4. Alternatively and less manfully, pop oysters into a microwave for 20 seconds or place on a hot grill top for two to three minutes until they open, finishing off the job with a knife if necessary.

Where to shell out...
Green's Restaurant & Oyster Bar, 36 Duke St, St James's, SW1. Tel: 020 7930 4566
Bibendum Oyster Bar, Michelin House, 81 Fulham Rd SW3. Tel: 020 7581 5817
Richard Corrigan at Lindsay House, 21 Romilly Street, London W1. Tel: 020 7439 0450
Fish! Cathedral Street, SE1 9AL. Tel: 020 7407 3803 (for the Fish! delivery service, tel: 0207 407 3801- rock oysters from 60p each); branches in Battersea, Waterloo, Docklands, Guildford and Birmingham. See www.diner.co.uk.
Loch Fyne Restaurants in Twickenham, 175 Hampton Rd, Twickenham. Tel: 0208 255 6222. Also in Barnet, Winchester, Cambridge, Nottingham and Peterborough, as well as at Loch Fyne, Cairndow on the West Coast of Scotland. See www.loch-fyne.com
Royal Naval Oyster Stores, The Horsebridge, Whitstable CT5 1BU. Tel: 01227 276856
Butley Oysterage, Market Hill, Orford, Suffolk. Tel: 01394 450277
Riverside Restaurant, West Bay, Dorset DT6 4EZ. Tel: 01308 422011