How to make the world’s best barbecue this summer

COOKING outside can be one of the joys of summer, but, like conducting an experiment outside the lab, it is harder to control all the variables – even if the weather is on your side.

A key question is which fuel to use. Charcoal is made by slowly burning wood in low-oxygen conditions. This drives off most of the water and other volatile compounds until the remainder – about 25 per cent of the original weight – is almost pure carbon, although some unburnt wood may remain in larger pieces of lumpwood charcoal.

You can also use charcoal briquettes. These are made from…