It’s important to be aware of the source of the charcoal and wood you use for cold and hot smoking. The wood should be natural and untreated, and from sustainable sources, as some charcoal fuels imported from overseas are unsustainably harvested and contribute to deforestation. I like to use food-grade sawdust (available from butchers) when I need quick smoking. When I need to smoke something for a longer time, I use hickory or oak woodchips or mallee root. Charcoal should be natural not petroleum-based. Also, I prefer to use a blowtorch to get the fire going instead of petroleum-based firelighters as they can taint the food.