Fifteen years ago, if you went into a supermarket, the only kind of soup you could buy was either powder in a packet or gloop in a tin. If you were a gourmet, you might fork out for more expensive and lobstery gloop, but there your options ended. These days, however, there are so many competing tubs of fresh, wholesome soups in the chill cabinets that the supermarkets can hardly make room for milk.

The business which started the trend, the New Covent Garden soup company, has just relaunched its entire range and is feeling rather pleased with itself. "Fresh soup didn't exist before us," claims the NCG website, "or at least not outside those homes and restaurants where time and patience were plentiful." In a founding myth the company is fond of telling, its founder, Andrew Palmer, felt ravenous after a day's sailing in 1987, and yearned for some of his mother's special home-cooked soup. Weirdly, instead of just going to the kitchen and making some soup for himself, Palmer immediately set to work to satisfy his craving by putting fresh soup in every supermarket in Britain. Before long the distinctively homespun TetraPaks of carrot and coriander soup were flying off the shelves.

Over the past six months, all of the recipes have been revised and numerous new flavours added, most of which cost 10-20p more than they used to (£1.65-£1.95 a carton). What do you get for your money? For one thing, a carton that thrillingly "opens both sides". For another, a whole lot of new flavours. As well as the old leek and potato, asparagus, spinach and nutmeg and wild mushroom (one of the company's best), it now sells "Italian Chunky Soup" (marketing-speak for a kind of minestrone), smoked haddock chowder and "Our Best Chicken Soup" (an unremarkable, white, peppery creation), ever-changing soups of the month and a special winter range including a musty "three bean and sage" and beetroot and rosemary. The new range has been "tested, tweaked and improved" to make the soups seem more home-made than ever; but the main effect, instead, is one of marketing contrivance. One sign of how tight an operation NCG is, is that it no longer gives surplus soup to the homeless because it no longer makes a surplus (though it does give money to Comic Relief).

The soups, though sometimes good, are nothing like as good as the best soup you could make yourself at home. The flavours are trapped in a kind of rustic modishness. You can't imagine New Covent Garden ever making a good cream of celery or consomme, for example. The website tells us that the new plum tomato and creme fraIche soup "offers the modern twist sought after by today's consumer". That twist is largely illusory, as the soup actually contains more ordinary double cream than it does creme fraIche; and tastes pleasant, but nothing more. Many of the new soups are too salty. Although a nice PR for the company assures me that it believes in "light seasoning", the new beetroot soup has 1.5g sodium per portion, seven times as much as a bag of children's crisps.

Harder to swallow than the soups themselves is the Pret a Manger-ish promotional literature that now gets slapped on the packaging. We are told that nutritional values may vary through the seasons because "Sorry, but that's nature for you". Under the heading "why our soup is so good", the label waffles that "The fact is, we live for soup . . . for subtle variations and unexpected combinations . . . and for a flavour that reflects the quiet dedication of our growers and the irresistible bustle of fresh produce markets", ignoring the truth that supermarket products such as this one make fresh produce markets a lot less bustling. Another piece of self-congratulation remarks: "There's nothing artificial about this fresh soup." But how "natural" can a product be, that spends so long protesting its own innocence?