Smoking (cooking)
Smoking is the process of flavoring, browning, cooking, or preserving food, particularly meat, fish and tea, by exposing it to smoke from burning or smoldering material, most often wood.
In Europe, alder is the traditional smoking wood, but oak is more often used now, and beech to a lesser extent. In North America, hickory, mesquite, oak, pecan, alder, maple, and fruit tree woods, such as apple, cherry, and plum, are commonly used for smoking. Other biomass besides wood can also be employed, sometimes with the addition of flavoring ingredients. Chinese tea-smoking uses a mixture of uncooked rice, sugar, and tea, heated at the base of a wok.
Some North American ham and bacon makers smoke their products over burning corncobs. Peat is burned to dry and smoke the barley malt used to make Scotch whisky and some beers. In New Zealand, sawdust from the native manuka is commonly used for hot-smoking fish. In Iceland, dried sheep dung is used to cold-smoke fish, lamb, mutton, and whale.
Historically, farms in the West included a smokehouse, a small building where meats could be smoked and stored. This was generally well separated from other buildings both because of fire danger and smoke emanations. The smoking of food may possibly introduce polycyclic aromatic hydrocarbons, which may lead to an increased risk of some types of cancer; however, this association is debated.
Food can be smoked by cold smoking, warm smoking or hot smoking. However, these methods of imparting smoke only affect the food surface, and are unable to preserve food, thus, smoking is paired with other microbial hurdles, such as chilling and packaging, to extend food shelf-life. Smoke-like flavor can be added by flavoring such as liquid smoke.
History
The smoking of food likely dates back to the Paleolithic era. This process was later combined with pre-curing the food in salt or salty brine, resulting in a remarkably effective preservation process that was adapted and developed by numerous cultures around the world. Until the modern era, smoking was of a more "heavy duty" nature as the main goal was to preserve the food. Large quantities of salt were used in the curing process and smoking times were quite long, sometimes involving days of exposure.The advent of modern transportation made it easier to transport food products over long distances and the need for the time and material intensive heavy salting and smoking declined. Smoking became more of a way to flavor than to preserve food. In 1939 a device called the Torry Kiln was invented at the Torry Research Station in Scotland. The kiln allowed for uniform mass-smoking and is considered the prototype for all modern large-scale commercial smokers. Although refinements in technique and advancements in technology have made smoking much easier, the basic steps involved remain essentially the same today as they were hundreds if not thousands of years ago.
by method of application
Cold smoking
Cold smoking differs from hot smoking in that it does not cook anything; when cold smoking is finished, the food is still raw. Smokehouse temperatures for cold smoking are typically between. In this temperature range, foods take on a smoked flavor, but remain relatively moist. Since cold smoking does not cook foods, meats should be fully cured before cold smoking. Cold smoking can be used as a flavor enhancer for items such as cheese or nuts, along with meats such as chicken breasts, beef, pork chops, salmon, scallops, and steak. The item is often hung in a dry environment first to develop a pellicle; it can then be cold smoked up to several days to ensure it absorbs the smoke flavor. Some cold smoked foods are baked, grilled, steamed, roasted, or sautéed before eating.Cold smoking meats should not be attempted at home, according to the US National Center for Home Food Preservation: "Most food scientists cannot recommend cold-smoking methods because of the inherent risks."
Cold smoking meats should only be attempted by personnel certified in HACCP to ensure that it is safely prepared.
Warm smoking
Warm smoking exposes foods to temperatures of.Hot smoking
Hot smoking cooks foods and simultaneously flavors them with smoke in a controlled environment such as a smoker oven or smokehouse. It requires consistent control of both the temperature of the food and the amount of smoke being applied to it. Some smokers have a heat source built into them, while others use the heat from a stove-top or oven. Like cold smoking, the item may be hung first to develop a pellicle; it is then smoked from 1 hour to as long as 24 hours. Although foods that have been hot smoked are often reheated or further cooked, they are typically safe to eat without further cooking. The temperature range for hot smoking is usually between. Foods smoked in this temperature range are usually fully cooked, but still moist and flavorful. At smoker temperatures hotter than, foods can shrink excessively, buckle, or even split. Smoking at high temperatures also reduces yield, as both moisture and fat are cooked away.Liquid smoke
, a product derived from smoke compounds in water, is applied to foods through spraying or dipping.Smoke roasting
Smoke-roasting refers to any process that has the attributes of both roasting and smoking. This smoking method is sometimes referred to as barbecuing or pit-roasting. It may be done in a smoke-roaster, a closed wood-fired oven, or a barbecue pit, any smoker that can reach above, or in a conventional oven by placing a pan filled with hardwood chips on the floor of the oven so that the chips can smolder and produce a smoke-bath. In North America, this smoking method is commonly referred to as "barbecuing", "pit baking", or "pit roasting".Types of fuel
Wood smoke
s are made up mostly of three materials: cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are the basic structural material of the wood cells; lignin acts as a kind of cell-bonding glue. Some softwoods, especially pines and firs, hold significant quantities of resin, which produces a harsh-tasting soot when burned; these woods are not often used for smoking.Cellulose and hemicellulose are aggregate sugar molecules; when burnt, they effectively caramelize, producing carbonyls, which provide most of the color components and sweet, flowery, and fruity aromas. Lignin, a highly complex arrangement of interlocked phenolic molecules, also produces a number of distinctive aromatic elements when burnt, including smoky, spicy, and pungent compounds such as guaiacol, phenol, and syringol, and sweeter scents such as the vanilla-scented vanillin and clove-like isoeugenol. Guaiacol is the phenolic compound most responsible for the "smoky" taste, while syringol is the primary contributor to smoky aroma. Wood also contains small quantities of proteins, which contribute roasted flavors. Many of the odor compounds in wood smoke, especially the phenolic compounds, are unstable, dissipating after a few weeks or months.
A number of wood smoke compounds act as preservatives. Phenol and other phenolic compounds in wood smoke are both antioxidants, which slow rancidification of animal fats, and antimicrobials, which slow bacterial growth. Other antimicrobials in wood smoke include formaldehyde, acetic acid, and other organic acids, which give wood smoke a low pH—about 2.5. Some of these compounds are toxic to people as well, and may have health effects in the quantities found in cooking applications.
Since different species of trees have different ratios of components, various types of wood do impart a different flavor to food. Another important factor is the temperature at which the wood burns. High-temperature fires see the flavor molecules broken down further into unpleasant or flavorless compounds. The optimal conditions for smoke flavor are low, smoldering temperatures between. This is the temperature of the burning wood itself, not of the smoking environment, which uses much lower temperatures. Woods that are high in lignin content tend to burn hot; to keep them smoldering requires restricted oxygen supplies or a high moisture content. When smoking using wood chips or chunks, the combustion temperature is often raised by soaking the pieces in water before placing them on a fire.
Types of smokers
Offset
The main characteristics of the offset smoker are that the cooking chamber is usually cylindrical in shape, with a shorter, smaller diameter cylinder attached to the bottom of one end for a firebox. To cook the meat, a small fire is lit in the firebox, where airflow is tightly controlled. The heat and smoke from the fire are drawn through a connecting pipe or opening into the cooking chamber.The heat and smoke cook and flavor the meat before escaping through an exhaust vent at the opposite end of the cooking chamber. Most manufacturers' models are based on this simple but effective design, and this is what most people picture when they think of a "BBQ smoker". Even large capacity commercial units use this same basic design of a separate, smaller fire box and a larger cooking chamber.
Reverse flow offset
A reverse flow offset smoker is a variation of the traditional offset design. In this configuration, a solid baffle plate or duct forces the heat and smoke to travel beneath the food before rising and reversing direction to exit through a chimney positioned on the same side as the firebox.This setup promotes more consistent temperatures across the cooking chamber and enhances smoke distribution, which can result in more even cooking. Reverse flow smokers are popular among pitmasters seeking stable heat and reduced hot spots.
Upright drum
The upright drum smoker is exactly what its name suggests: an upright steel drum that has been modified for the purpose of pseudo-indirect hot smoking. There are many ways to accomplish this, but the basics include the use of a complete steel drum, a basket to hold charcoal near the bottom, and a cooking rack near the top, all covered by a vented lid of some sort. These smokers have been built using many different sizes of steel drums, such as,, and, but the most popular size is the common 55-gallon drum.This design is similar to smoking with indirect heat due to the distance between the coals and the cooking racks, which is typically. The temperature is controlled by limiting the air intake at the bottom of the drum, and allowing a similar amount of exhaust out of vents in the lid. UDSs use their fuel very efficiently, and are flexible in their ability to produce proper smoking conditions with or without the use of a water pan or drip pan.