Cold smoking is a process that smokes meat without exposing it to heat, usually at temperatures below 85°F (30°C). Unlike hot smoking, this process can take days or weeks to complete, and it tends to yield drier, salty foods.
The prolonged smoking process yields a complex flavor development, but it also requires careful work to do correctly, as the perfect conditions for cold smoking are also ideal for the promotion of bacterial growth. It is also difficult to accomplish in hot conditions, which is why the process tends to be done more often in cuisines from colder regions of the world, such as Scandinavian nations.
During the smoking process, the smoke is usually generated in a chamber separate from the meat and passed through pipes so that it cools before it reaches the meat. Typically, the meat is held close to room temperature, and in relatively dry conditions. More intensely smoked meats will be smoked longer, while other cooks smoke meats briefly for a hint of flavor.
Since cold smoking does not technically cook or extensively cure the meat, it is usually brined or salted first. Salting meat ensures that bacteria will not develop while it is smoked and stored. Some foods, such as lox, that are classically prepared in this way also have an identifiably salty flavor, due to the brining that the meat undergoes before it is put in the cold smoker.
Typically, cooks cold smoke in the winter, when temperatures are cooler and more controllable. In warmer weather, the temperature in the smoker can rise too high, putting a halt to the process. In extremely warm climates, such as those in the tropics, it is impossible to prepare meat with this method, since temperatures never get cool enough. Excessive heat can also result in rapid putrefaction, which is extremely undesirable.
Because the meat is not cooked, it tends to have a characteristic smooth texture that often reminds consumers of the uncooked food product. The smoke does not fully preserve the food, so it should be kept under refrigeration until it is used, and expiration dates should be carefully observed. Some cold smoked food must also be cooked before use, especially if it has been lightly cured, as is the case with bacon. Others, like Black Forest ham, can be eaten raw as long as they are well handled.