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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 sawdust and wood scraps that are burned in the same way as when making charcoal, then crushed and mixed with additives to bind the contents, help with ignition or promote steady burning, before being moulded into uniform shapes. Because these shapes are uniform, they usually hold their heat longer than lumpwood charcoal.

For both fuels, the quickest, easiest way to light them is to use a , a metal tube with two cavities. You put paper in the bottom one and charcoal in the top, then light the paper. The burning paper sucks in oxygen and ignites the coals, creating an updraft that allows heat to build quickly, so the coals are ready for cooking in about 15 minutes.

Charcoal burns hotter than wood and produces very little smoke. This means that it contributes very little flavour to whatever is cooked on it.

The smoky taste we associate with barbecues mostly comes from fat and juices that drip from the food onto the hot coals. These drips ignite and produce smoke containing flavourful aromatic compounds that are deposited on the food’s surface. Some cooks like to add wood chips on top of the coals to add extra smoky aromas.

Since charcoal isn’t a significant source of flavour, you might prefer the convenience of a gas barbecue, which is quick to light and easier to control. Gas is also much more efficient to produce and cook with: the carbon footprint of gas grilling is – though it comes from a non-renewable source.

The other factor that makes barbecued food taste different to food cooked in your kitchen is heat. Glowing coals exceed 1000°C and give off considerable infrared radiation. This searing heat drives the Maillard reaction, which transforms sugars and amino acids into hundreds of delicious flavour compounds. But it can also result in food that is charred on the outside and cold in the middle.

The best way to avoid the latter is to pile coals on one side of the grill. You can then move food from the hot area to a cooler part if the outside is charring too quickly. I would also recommend buying a cooking thermometer, which makes it easy to tell when meat is done all the way through.

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