Something special is going on in London tonight, with a buzz already building around a new designer product to be unveiled in the witching hour. Restaurateurs, chefs and fashion-conscious foodies will be among those jostling for sizzling fare prepared in a special field kitchen, and if their samples match up to the one I just tasted, the cry of the night will be: "I can't believe it didn't need butter".
The product is Rudolph, a new breed of potato developed to be so fluffy that it needs no fat to lubricate its flesh – an attribute set to repair the dietary reputation of spuds, which were once our ubiquitous choice of starch.
They fell out of favour nearly a decade ago thanks to the wholesale embrace of a Mediterranean-style diet built around pasta and olive oil, but the recession is bringing them back. Potatoes are the food story of the credit-crunch era: cheap, filling and nutritious – at least when cooked in their skins to preserve all the vitamin C. But the £4bn British potato market has come a very long way from the days of one-breed-fits-all, even if the Maris Piper, bred 50 years ago to be versatile as well as perfect for chips, is still the nation's favourite.
Maybe not for much longer. "The real 'Brit Pots' are heritage breeds that have stood the test of time in terms of taste and versatility," claims Sue Gilbert, marketing manager of Greenvale, the UK's largest supplier of fresh potatoes. It has just teamed with Sainsbury's to market four older varieties once neglected by growers, now packaged specifically for roasting.
"These breeds might have vanished from the supermarket shelves because of their short growing season, but they have been kept alive by gourmets and specialist growers alike," Gilbert points out. The four varieties, which will rotate, according to season, into the 'Roasties' packages on Sainsbury's shelves include the Red King Edward – which rival supermarket Waitrose claims would have become extinct if their own agronomist and potato expert Alan Wilson hadn't stepped in to save it three years ago.
"Traditional varieties such as these are harder to grow and produce a lower yield, which has an effect on availability and price," explains Bethan Davies, spokeswoman for Waitrose. The store markets its own "heritage" packs, but holds out the Red King Edward, which indeed roasts superbly, as a variety worth marketing by name.
Rare old species are being resurrected as fast as new ones are being developed. The tiny Northumberland family firm of Carrolls lists additions to its range of heritage potatoes as reverently as if they were vintage wines. Their latest list includes Mr Little's Yetholm Gypsy of 1899, with its red, white and blue skin, and a Victorian favourite, Shetland Black. The Highland Burgundy is lividly coloured all the way through, apart from a smart stripe just under the skin, and the Salad Blue has flesh of surprising inky purple, which apparently can make very interesting crisps.
The Carrolls, Anthony and Lucy, started growing heritage varieties as an experiment in 2001 and the spuds were so popular at their local farmers' market that they added more varieties.
Meanwhile, the Co-op has grown its own new variety of salad potato, the Pioneer, and if green- grocers take up Rudolph, the two new varieties will together launch a new taste sensation.
This frenetic burst of interest from growers and retailers is a response to demand from the public for more interesting fresh food, says Denis Alder of the Potato Council.
He cites "the Jamie Oliver effect" in the reversal of fortune of the spud. "We saw a noticeable decline in consumption from 2002, followed by a gentle rise in the past two or three years," he says. "Potato sales have been lifted by encouragement from the Government to eat more fresh food, and by the public taking more interest in what they eat and how to cook it."
Undoubtedly chefs have played their part in the potato revival, or we would not have seen the addition of rarefied items like goose fat to the shelves of major supermarkets specifically for roasting potatoes. There can be few keen cooks who do not now know that after blanching, roasters have to be bashed against the side of the pan to fluff them up a bit, as demonstrated by Jamie, before being lowered into sizzling goose or duck fat. But while that method may be as old as the hills, it took Heston Blumenthal to discover that boiling potato peelings in a pan with the pared spuds during blanching would yield roasties with twice the flavour.
Posher chefs have come back to spuds, too. "For two years I chose to cook almost completely without potatoes," admits Skye Gyngell, head chef of the cafe at Petersham Nurseries. "They were, I felt, too heavy for my style of cooking. But I rediscovered their subtle beauty when I picked little Red Dukes from the ground on a farm in Gloucestershire." She emphasises the need to get potatoes from ground to plate as soon as possible, and a grow-your-own-spud initiative has been reinforced by both cooking and gardening programmes.
Supermarkets have also been very active in the attempt to decommodify and glorify the humble potato, adds Alder, with more attractive packaging as well as guidance on which variety is best for which use. This is vital knowledge, as anyone who has tried vainly to make potato salad or pommes dauphinoises with a floury, non-waxy variety, or to mash a waxy type, will know.
Just as L'Oreal's attempts to decommodify shampoo have meant harnessing big names like Eva Longoria to toss her shiny mane, Albert Bartlett have signed another Desperate Housewife, Marcia Cross, to push its Rooster, Britain's first, and best-selling, grower-branded potato. A third of all red potatoes bought in Britain are Roosters, and Bartlett saw its sales grow 45 per cent last year following another – non-celebrity – burst of television advertising.
This £3m Rooster campaign featuring a Hollywood name – surely a first in Brtish greengrocery – is based on solid research. The Potato Council has found that housewives aged over 45 account for two-thirds of Britain's potato spend, so Cross was an obvious role model. Concerned that younger consumers often overlook potatoes, the Council itself last year launched Facebook and Twitter pages to try and encourage a new generation to pick up the potato habit.
Branding looks like becoming the name of the game, with the Jersey Royal company, whose new potatoes are among very few varieties to command a premium, about to launch the Miniature Pearl Potato. It will be the island's first brand protected by a certificate of origin.
Britain's most famous greengrocer, BBC's Gregg Wallace, applauds the Sainsbury's initiative to select and market potatoes for a specific use. "This is how the firm I co-own, Secretts Direct, markets to chefs," he says. "Not by variety, but as mashers, roasters or chippers. Once we know what the chefs want them for, we select the best variety. Many varieties have low yields, so it's great to see them being saved by a policy of rotating with other types fit for the same use." He is thrilled with the revival of the potato.
"For years, people have been so disappointed when I tell them it's my favourite vegetable. Chefs have never turned against them, because they know what a great accompaniment they are – so much more versatile than rice or pasta, which are boring by comparison." Wallace points out that regardless of variety, the starch component of spuds turns to sugar with storage, which can affect its suitability for a specific use.
Max Clarke, co-author of Leith's Vegetable Bible, says no store-bought potato will ever taste as good as home-grown: "I believe a resurgence of interest in potatoes is down to encouragement from dynamic young chefs to grow your own, as I did for the first time last year.
"I combined two varieties in an old dustbin," Clarke says. First there was "the gorgeous young Anya, which is waxy and great for salads but absorbent enough to soak up other flavours, like chorizo, or black olive and basil ... I also grew Desiree, which really is a good all-rounder. It mashes and roasts beautifully as well as making good chips; and Sante, which has a brilliant chestnutty flavour and is great for baking whole in the skin, rolled in olive oil and sprinkled with sea salt.
"Potatoes are so delicious, but I think it has taken hard times for people to realise that this food, which doesn't cost very much, tastes really great. And to see the supermarkets go from labelling a potato as merely old or new, red or white, to naming varieties and indicating what they are best used for is a revelation."
Boil, bake or fry: Which kind to use
It's important to know your spuds if you are to get the best results. The following is a guide to which varieties are best for each of the main cooking methods:
All-rounders: Desiree, King Edward (the ubiquitous white variety), Maris Piper
Roasting: Red King Edward, Red Duke of York
Boiling: Estima (preferably newly dug)
Mashing: Rooster, Wilja, Rudolph
Salad: Anya, Charlotte, Pink Fir Apple, Ratte
Chips: Maris Piper
Baking: Sante, Rudolph, Estima and the all-rounders
Hot potatoes: Varieties to try
Highly coloured and highly flavoured, it's named after the Duke of Burgundy, who used to enjoy this decorative potato at the Savoy. Simmer, steam, roast, chip or sauté.
With a gorgeous, inky colour it will make deliciously surprising crisps, chips or mash, and can be sautéd, boiled, roasted or baked too.
Pink Fir Apple
Long in shape and famously knobbly, this is a traditional variety with waxy flesh and a wonderful new-potato flavour. Best served boiled in its skin.
With a long oval shape and a distinctive blue ring inside, this floury potato is great for frying, and can also be baked, roasted or steamed.
The Witchill looks ordinary, but the flavour will remind you how potatoes were always meant to be. Boil, roast or steam.
All available from Heritage-potatoes.co.uk