Most often used in welding, a blowtorch is a device that uses combustible gas to make flames hot enough to provide precise cuts in metal or fuse metal pieces together. Also called blowlamps, types of blowtorches range from professional grade to small kitchen torches found in culinary stores. The type of blowtorch used depends on the type of task involved.
Chefs will use smaller torches in certain recipes, such as crème brule which requires sudden high heats to caramelize its sugary top, or to roast vegetables.
professional grade blowtorch consists of two cylinders, one for the oxygen and one for the fuel, and a metal head with a removable tip, which can be changed depending on the task. Two regulators and two color-coded rubber hoses connect the canisters to the torch. The regulators are adjustable and control the torch's gas pressure.
Small non-professional blowtorches use butane or propane. Propane or butane torches do not have an oxygen cylinder inside them. Instead, they use outside air to burn the gas they contain, much like simple lighters. For this reason, they are cooler than professional torches, but do reach 3,200-3,800°F (1,760-2,093°C). Non-professional blowtorches can be found in hardware stores, and as well as some gourmet food stores.