Smoking

Smoking is the process of, , or  by exposing it to the  from burning or smoldering plant materials, most often. and are the most common smoked foods, though cheeses,, and ingredients used to make  such as ,  and lapsang souchong tea are also smoked.

In, is the traditional smoking wood, but  is more often used now, and  to a lesser extent. In, , , oak, , alder, , and fruit-tree woods, such as , and , are commonly used for smoking. Other fuels besides wood can also be employed, sometimes with the addition of flavoring ingredients. Chinese tea-smoking uses a mixture of uncooked, , and tea, heated at the base of a. Some North American and bacon makers smoke their products over burning. is burned to dry and smoke the  used to make  and some. In New Zealand, sawdust from the native (tea tree) is commonly used for hot smoking fish. In, dried sheep dung is used to cold smoke fish, lamb, mutton and whale.

Historically, farms in the Western world included a small building termed the , where meats could be smoked and stored. This was generally well-separated from other buildings both because of the fire danger and because of the smoke emanations.

Types

 * Cold smoking can be used as a flavor enhancer for items such as breasts,, , , , and . The item can be cold smoked for just long enough to give some flavor. Some cold smoked foods are , , , or  before eating. Smokehouse temperatures for cold smoking are below 100 °F. In this temperature range, foods take on a smoked flavor, but remain relatively moist. Cold smoking does not cook foods. Meats should be fully cured before cold smoking.


 * Hot smoking exposes the foods to smoke and heat in a controlled environment. Although foods that have been hot smoked are often reheated or cooked, they are typically safe to eat without further cooking. and  are fully cooked once they are properly smoked. Hot smoking occurs within the range of  165 °F to 185 °F. Within this temperature range, foods are fully cooked, moist, and flavorful. If the smoker is allowed to get hotter than 185 °F, the foods will shrink excessively, buckle, or even split. Smoking at high temperatures also reduces yield, as both moisture and fat are "cooked" away.


 * Smoke roasting or smoke baking refers to any process that has the attributes of smoking combined with either roasting or baking. This smoking method is sometimes referred to as "barbecuing", "pit baking", or "pit roasting". It may be done in a smoke roaster, closed wood-fired or  pit, any smoker that can reach above 250 °F, or in a conventional oven by placing a pan filled with hardwood chips on the floor of the oven so the chips  and produce a smokebath. However, this should only be done in a well-ventilated area to prevent.

Wood smoke
are made up mostly of three materials:, , and. Cellulose and hemicellulose are the basic structural material of the wood ; lignin acts as a kind of cell-bonding glue. Some, especially and , hold significant quantities of , which produces a harsh-tasting soot when burned; these woods are not often used for smoking.

Cellulose and hemicellulose are aggregate molecules; when burnt, they effectively, producing , which provide most of the color components and sweet, flowery, and fruity aromas. Lignin, a highly complex arrangement of interlocked molecules, also produces a number of distinctive aromatic elements when burnt, including smoky, spicy, and pungent compounds such as, , and , and sweeter scents such as the -scented  and -like. Guaiacol is the phenolic compound most responsible for the "smokey" taste, while syringol is the primary contributor to smokey aroma. Wood also contains small quantities of, 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, which slow of animal fats, and antimicrobials, which slow bacterial growth. Other antimicrobials in wood smoke include, , and other organic acids, which give wood smoke a low —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. See Health Effects.

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 570 and 750°F. 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 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
There are a few basic types of smoker designs, each with their own advantages and disadvantages.

Offset smokers
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 is 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.

The UDS
The Upright Drum Smoker (also referred to as an Ugly Drum Smoker or UDS) 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 cooking rack (or racks) near the top; all covered by a vented lid of some sort. They have been built using many different sizes of steel drums (30 gallon, 55 gallon, and 85 gallon for example), but the most popular size is the common 55 gallon drum.

This design is similar to smoking with indirect heat due to the distance from the coals and the racks (typically 24"). The temperatures used for smoking are controlled by limiting the amount of air intake at the bottom of the drum, and allowing a similar amount of exhaust out of vents in the lid. UDSs are very efficient with fuel consumption and flexible in their abilities to produce proper smoking conditions, with or without the use of a water pan or drip pan. Most UDS builders/users would say a water pan defeats the true pit BBQ nature of the UDS, as the drippings from the smoked meat should land on the coals, burning up, and imparting a unique flavor one cannot get with a water pan.

Vertical water smoker
A vertical water smoker (also referred to as a bullet smoker because of its shape) is a variation of the upright drum smoker. It uses charcoal or wood to generate smoke and heat, and contains a water bowl between the fire and the cooking grates. The water bowl serves to hold the temperature down and also to add humidity to the smoke chamber. In addition, the bowl catches any drippings from the meat that may cause a flare up. Vertical water smokers are extremely temperature stable and require very little adjustment once the desired temperature has been reached. Because of their relatively low cost and stable temperature, they are sometimes used in barbecue competitions where propane and electric smokers are not allowed.

Propane smoker
A propane smoker is designed to allow the smoking of meat in a somewhat more controlled environment. The primary differences are the sources of heat and of the smoke. In a propane smoker, the heat is generated by a gas burner directly under a steel or iron box containing the wood or charcoal that provides the smoke. The steel box has few vent holes, on the top of the box only. By starving the heated wood of oxygen, it smokes instead of burning. Any combination of woods and charcoal may used. This method uses less wood.

Smoke box method
This more traditional method uses a two box system: The fire box and the food box. The fire box is typically adjacent or under the cooking box, and can be controlled to a finer degree. The heat and smoke from the fire box exhausts into the food box, where it is used to cook and smoke the meat. These may be as simple as an electric heating element with a pan of wood chips placed on it, although more advanced models have finer temperature controls.

Commercial smoke house
Commercial smokehouses, mostly made from stainless steel, have independent systems for smoke generation and cooking. Smoke generators use friction, an electric coil or a small flame to ignite sawdust on demand. Heat from steam coils or gas flames is balanced with live steam or water sprays to control the temperature and humidity. Elaborate air handling systems reduce hot or cold spots, to reduce variation in the finished product. Racks on wheels or rails are used to hold the product and facilitate movement.

Preservation
Smoke is an antimicrobial and antioxidant, but smoke alone is insufficient for preserving food in practice, unless combined with another preservation method. The main problem is the smoke compounds adhere only to the outer surfaces of the food; smoke does not actually penetrate far into meat or fish. In modern times, almost all smoking is carried out for its flavor. Artificial smoke flavoring can be purchased as a liquid to mimic the flavor of smoking, but not its preservative qualities (see also ).

In the past, smoking was a useful preservation tool, in combination with other techniques, most commonly or. In some cases, particularly in climates without much hot sunshine, smoking was simply an unavoidable side effect of drying over a fire. For some long-smoked foods, the smoking time also served to dry the food. Drying, curing, or other techniques can render the interior of foods inhospitable to bacterial life, while the smoking gives the vulnerable exterior surfaces an extra layer of protection. For oily fish smoking is especially useful, as its antioxidant properties delay surface fat. (Interior fat is not as exposed to, which is what causes rancidity.) Some heavily-salted, long-smoked fish can keep without refrigeration for weeks or months. Such heavily-preserved foods usually require a treatment such as boiling in fresh water to make them palatable before eating.

Cancer risk
"Of various sources of N-nitroso compounds, intake of smoked and salted fish was significantly (RR = 2.58, 95% CI 1.21 ? 5.51) and intake of cured meat was non-significantly (RR = 1.84, 95% CI 0.98– 3.47) associated with risk of colorectal cancer."

Some smoked foods
Many foods can be smoked. Some of the more common are listed here.
 * Beverages
 * Lapsang souchong tea leaves are smoked and dried over pine or cedar fires
 * beverages
 * The malt used to make
 * (smoked beer)


 * Fruit and vegetables
 * : (smoked, ripe  ),
 * (dried ) can be smoked while drying
 * Wumei are smoked fruits
 * Iburi-gakko are a smoked  from ,


 * Protein
 * Cheeses
 * popular in eastern/northern Europe
 * (cod and haddock)
 * and (haddock)
 * and (herring)
 * Traditionally-prepared
 * (pickled, spiced and smoked )
 * Bacon
 * Various sausages
 * Various kinds of s
 * (pickled, spiced and smoked )
 * Bacon
 * Various sausages
 * Various kinds of s
 * Various sausages
 * Various kinds of s
 * Various kinds of s
 * Various kinds of s


 * Spices