For connoisseurs though, the macho hullabaloo about ever-hotter chilies is distasteful, even vulgar: rather like rating wine only according to its alcohol content. Steve Waters, who runs the South Devon Chili Farm, says even the idea that the spectrum runs on a simple one-dimensional axis between "hot" and "mild" is misleading. He prefers the more complex Mexican matrix, which categorises chilies both by heat, and whether they are fresh, dried, pickled, or smoked. Any of these can produce big changes in flavour: he highlights the Aji (pronounced ah-hee), a Peruvian chili, which "ripens to bright yellow, with a strong lemony taste when fresh, very zesty. When dried it picks up a banana flavour."

From this point of view, the most interesting trend is not in ever-higher doses of capsaicin for the maniac market, but in the presence of chili in a range of foodstuffs that previous generations would have regarded as preposterous candidates for hotting up. Chili-flavoured chocolate, for example, has gone from being a novelty item to a popular mainstream product. Mr Waters sells "hot apple chili jelly" as a condiment for meat, and chili-infused olive oil.

The reason may be that capsaicin excites the trigeminal nerve, increasing the body's receptiveness to the flavour of other foods. That is not just good news for gourmets. It is a useful feature in poor countries where the diet might otherwise be unbearably bland and stodgy. In a study in 1992 by the CSIRO's Sensory Research Centre, scientists looked at the effect of capsaicin on the response to solutions containing either sugar or salt. The sample was 35 people who all ate spicy food regularly but not exclusively. Even a small quantity of capsaicin increased the perceived intensity of the solutions ingested. Among other things, that may give a scientific explanation for the habit, not formally researched, of snorting the "pink fix" (a mixture of cocaine and chili powder).

... contd.