The original intent of smoking food was to preserve as well as add flavour: wood smoke has a low pH and is full of chemicals that retard microbes including formaldehyde and acetic acid. To be sure, the preservative effects of smoking are not as pronounced as salt-curing food but both methods complement each other. Smoked and cured meats outlast fresh by months. Hickory-smoked bacon is a godsend.

With the advent of refrigeration smoking is no longer at all necessary as a preservative (nor for that matter, is salt-curing). Smoking is superfluous but the aroma, flavour and a deep caramel hue of well-smoked foods is unmatched by any other method.

As a chemical reaction, smoking is as complex as it is deeply intriguing. At different combustion temperatures, the different components of wood (cellulose, hemicellulose and lignin) produce a multitude of aromatic byproducts. Every food scientist’s favorite scientist, Harold McGee breaks this down in his tome, On Food and Cooking:

Burning temperatures transform each of the wood components into a characteristic group of compounds. The sugars in cellulose and hemicellulose break apart into many of the same molecules found in caramel, with sweet, fruity, flowery, bready aromas. And the interlocked phenolic rings of lignin break apart from each other into a host of smaller, volatile phenolics, which have the specific aromas of vanilla and clove, as well as generic spiciness, sweetness and pungency

The ability to coax this rich palette from wood is incredible and different woods burn and smoke at higher or lower temperatures depending on lignin and water content, which in turn imparts different intensities of flavours. Smoke helps stabilise the flavours of meat but smoke flavour itself is unstable. Some of the most desirable flavours, especially the vanilla and clove, dissipate into the ether within a matter of weeks. It is not only meat that benefits from smoke: malt roasted over peat fires gives whisky some of its characteristic aromas; and any vegetable matter from tofu to flour can be used as a host for smoke.

The simplest way to add more smoke flavour to your average barbecue is to add woodchips soaked overnight in water to it. Any wood with the exception of resinous soft woods, green wood or treated timber is suitable. Hickory is the classic American timber for smoking as it imparts a deep amber colour and bluntly smoke-spicy flavour and is best suited to smoking big, dumb, heavily -spiced or –marinated cuts of meat. Fruitwoods such as apple, pear or cherry are much subtler; and branches of dried herbs can add ever more complexity. There is much more experimenting required from Australian timbers.