I AM A small-hours radio listener and often get up in the morning with a head full of haphazard facts gleaned from dipping in and out of the BBC’s World Service. There was a report last week claiming that the bitter orange harvest in Spain has been one of the largest on record. Seville, as any marmalade-maker will know, is the epicentre of bitter orange growing. Though the farms are outside the city, orange trees line many streets and the ripening fruit create gorgeous, natural decoration in December and January.

Bitter oranges originated in China and Burma but have been grown in Spain since the tenth century. They were introduced by the Moors who believed both the juice and neroli, the perfume distilled from the skin, had health benefits. But as the world knows, bitter oranges are now known only as the ingredient for a breakfast essential. Spain grows enough to satisfy the world’s appetite for marmalade, so what happens when the harvest is so plentiful?