Waiter, what's this sulfite doing in my pint?

A man drains his pint glass of beer - but how can he be sure what's in it? Photograph: Bruno Vincent/Getty

As spring turns to summer, the mind naturally turns to thoughts of drink, writes David Fickling. And from drink it progresses to thoughts of drunkenness, and the eternal round of hangover, regret, and hasty vows.

Seasoned drinkers have long argued that the thumpingest hangovers are the byproduct not of alcohol, but of the chemical additives that are added to drinks to improve their shelf-life, appearance, taste and scent.