Native to West Africa the synsepalum dulcificum is not much bigger than a grape and, other than an attractive red skin, is rather unassuming. But now the "miracle fruit", as it is being called, has become the toast of the culinary elite for its miraculous ability to change the way your mouth works – making sour things taste magically sweet.

The berry contains a glycoprotein that temporarily masks your mouth's ability to taste sour and bitter notes. Once the pulp is swilled around the mouth and the large stone spat out, lemons suddenly taste like sugary lemonade, vinegar takes on a peculiar treacly tang and Irish stout tastes frighteningly similar to chocolate milkshake.

In New York and San Francisco, the latest fashionable night out is to attend an evening "fruit dropping". Partygoers chew berries or pop (perfectly legal) pills of dried pulp before wolfing down enormous quantities of seemingly metamorphosed foodstuffs.

In Britain, meanwhile, demand for the fruit has grown to the extent that the country's two main suppliers have warned customers they may have to wait weeks before getting any.

Chas Barr, a former IT specialist from south London, began selling berries through his website miraclefruit.co.uk after reading about them eight months ago on a botanical blog. He says demand has soared. "If I was lucky, I might have made, say, £5 a day," he said. "But in the past couple of weeks it has gone nuts. I'm selling thousands of pounds worth in a week, literally kilos every day."

Jonathan Hobbs, who ships fresh and freeze-dried berries using the site, says "fruit dropping" is becoming popular. "An amazing thing about miracle fruit is the range of people who want to try it," he says. "It does seem to be a bit of an internet phenomenon."

Although the effect has yet to be backed up by scientific evidence, fruit growers say miracle berries are popular with chemotherapy patients because they help diminish the unpleasant metallic aftertaste that comes with treatment. Others say the fruit could one day produce a natural alternative to sugar that would be suitable for diabetics.

The taste test

Just getting hold of some miracle fruit is half the fun. Very few people sell it and most of those that do are struggling to cope with demand. In Britain miraclefruit.co.uk and miracleuk.info sell berries and powder.

Lemons:

Citric fruits are a fruit droppers' favourite tipple because the effect is so dramatic. For me, the effect was quite simply astounding. I was able to munch my way through an entire lemon without a squint. The sour tang had been completely replaced by a smooth sugary taste, a little like a sherbert lemon or homemade lemonade.

Vinegar:

Vinegar tasted nothing like it did before when I had nearly vomited trying to swallow a gulp down. Although it still tasted like vinegar, the acidic tones had completely disappeared and had taken on an almost treacle taste.

Pineapple:

The pineapple chunks I tried were almost unbearably sweet, a sickly version of pineapple cube sweets.