Smoking (cooking technique) - AbsoluteAstronomy.com

Smoking is the process of flavoring

Seasoning

Seasoning is the process of imparting flavor to, or improving the flavor of, food.- General meaning :Seasonings include herbs and spices, which are themselves frequently referred to as "seasonings"...

, cooking

Cooking

Cooking is the process of preparing food by use of heat. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental, economic, and cultural traditions. Cooks themselves also vary widely in skill and training...

, or preserving

Food preservation

Food preservation is the process of treating and handling food to stop or slow down spoilage and thus allow for longer storage....

food

Food

Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

by exposing it to the smoke

Smoke

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...

from burning or smoldering plant materials, most often wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

. Meat

Meat

Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...

s and fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

are the most common smoked foods, though cheese

Cheese

Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

s, vegetable

Vegetable

The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....

s, and ingredients used to make beverages such as whisky

Whisky

Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Different grains are used for different varieties, including barley, malted barley, rye, malted rye, wheat, and corn...

, Rauchbier and lapsang souchong
Lapsang souchong
Lapsang souchong is a black tea originally from the Wuyi region of the Chinese province of Fujian. It is sometimes referred to as smoked tea...

tea

Tea

Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...

are also smoked.

In Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, alder

Alder

Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...

is the traditional smoking wood, but oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

is more often used now, and beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

to a lesser extent. In North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, hickory

Hickory

Trees in the genus Carya are commonly known as hickory, derived from the Powhatan language of Virginia. The genus includes 17–19 species of deciduous trees with pinnately compound leaves and big nuts...

, mesquite

Mesquite

Mesquite is a leguminous plant of the Prosopis genus found in northern Mexico through the Sonoran Desert and Chihuahuan Deserts, and up into the Southwestern United States as far north as southern Kansas, west to the Colorado Desert in California,and east to the eastern fifth of Texas, where...

, oak, pecan

Pecan

The pecan , Carya illinoinensis, is a species of hickory, native to south-central North America, in Mexico from Coahuila south to Jalisco and Veracruz, in the United States from southern Iowa, Illinois, Missouri, and Indiana east to western Kentucky, southwestern Ohio, North Carolina, South...

, alder, maple

Maple

Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

, and fruit-tree woods, such as apple

Apple

The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family . It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans. Apple grow on small, deciduous trees that blossom in the spring...

, cherry

Cherry

The cherry is the fruit of many plants of the genus Prunus, and is a fleshy stone fruit. The cherry fruits of commerce are usually obtained from a limited number of species, including especially cultivars of the wild cherry, Prunus avium....

and plum

Plum

A plum or gage is a stone fruit tree in the genus Prunus, subgenus Prunus. The subgenus is distinguished from other subgenera in the shoots having a terminal bud and solitary side buds , the flowers in groups of one to five together on short stems, and the fruit having a groove running down one...

, 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 rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

, sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

, and tea

Tea

, heated at the base of a wok

Wok

A wok is a versatile round-bottomed cooking vessel originating in China. It is used especially in East and Southeast Asia.Woks are most often used for stir frying, but can also be used in other Chinese cooking techniques, such as in steaming, deep frying, braising, stewing, smoking, or making soup...

. Some North American ham

Ham

Ham is a cut of meat from the thigh of the hind leg of certain animals, especiallypigs. Nearly all hams sold today are fully cooked or cured.-Etymology:...

and bacon

Bacon

Bacon is a cured meat prepared from a pig. It is first cured using large quantities of salt, either in a brine or in a dry packing; the result is fresh bacon . Fresh bacon may then be further dried for weeks or months in cold air, boiled, or smoked. Fresh and dried bacon must be cooked before eating...

makers smoke their products over burning corncob

Corncob

A corncob is the central core of a maize ear.The corn plant's ear is also considered a "cob" or "pole" but it is not fully a "pole" until the ear is shucked, or removed from the plant material around the ear...

s. Peat

Peat

Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...

is burned to dry and smoke the barley

Barley

Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...

malt

Malt

Malt is germinated cereal grains that have been dried in a process known as "malting". The grains are made to germinate by soaking in water, and are then halted from germinating further by drying with hot air...

used to make whisky and some beer

Beer

Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...

s. In New Zealand, sawdust from the native manuka

Leptospermum scoparium

Leptospermum scoparium is a shrub or small tree native to New Zealand and southeast Australia. Evidence suggests that L. scoparium originated in Australia before the onset of the Miocene aridity and dispersed relatively recently from Eastern Australia to New Zealand. It is likely that on arrival...

(tea tree) is commonly used for hot smoking fish. In Iceland

Iceland

Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

, 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 smokehouse
Smokehouse
A smokehouse is a building where meat or fish is cured with smoke. The finished product might be stored in the building, sometimes for a year or more.-History:...

, 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 chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

breasts, beef
Beef
Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...

, pork chops, salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...

, scallops, and steak
Steak
A steak is a cut of meat . Most are cut perpendicular to the muscle fibers, improving the perceived tenderness of the meat. In North America, steaks are typically served grilled, pan-fried, or broiled. The more tender cuts from the loin and rib are cooked quickly, using dry heat, and served whole...

. The item can be cold smoked for just long enough to give some flavor. Some cold smoked foods are baked, grilled, roasted, or sautée
Sautee
Sautee may refer to:*Sautee Nacoochee, Georgia*Sautee Valley Historic District*Sautéing, a method of cooking food....

d before eating. Smokehouse temperatures for cold smoking are below 100 °F (37.8 °C). In this temperature range, foods take on a smoked flavor, but remain relatively moist. Cold smoking does not cook foods.

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. Hams and ham hock
Ham hock
A ham hock or hough is the joint between the tibia/fibula and the metatarsals of the foot, where the foot was attached to the hog's leg...

s are fully cooked once they are properly smoked. Hot smoking occurs within the range of 165 °F (73.9 °C) to 185 °F (85 °C). Within this temperature range, foods are fully cooked, moist, and flavorful. If the smoker is allowed to get hotter than 185 °F (85 °C), 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 masonry oven
Masonry oven
A masonry oven, colloquially known as a brick oven or stone oven, is an oven consisting of a baking chamber made of fireproof brick, concrete, stone, or clay. Though traditionally wood-fired, coal-fired ovens were common in the 19th century, modern masonry ovens are often fired with natural gas or...

or barbecue
Barbecue
Barbecue or barbeque , used chiefly in the United States, Canada, the United Kingdom, New Zealand and Australia is a method and apparatus for cooking meat, poultry and occasionally fish with the heat and hot smoke of a fire, smoking wood, or hot coals of...

pit, any smoker that can reach above 250 °F (121.1 °C), or in a conventional oven by placing a pan filled with hardwood chips on the floor of the oven so the chips smolder and produce a smokebath. However, this should only be done in a well-ventilated area to prevent carbon monoxide poisoning
Carbon monoxide poisoning
Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide . Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect...

.

Wood smoke

Hardwood

Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...

s are made up mostly of three materials: cellulose

Cellulose

Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

, hemicellulose

Hemicellulose

A hemicellulose is any of several heteropolymers , such as arabinoxylans, present along with cellulose in almost all plant cell walls. While cellulose is crystalline, strong, and resistant to hydrolysis, hemicellulose has a random, amorphous structure with little strength...

, and lignin

Lignin

Lignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants and some algae. The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum, meaning wood...

. Cellulose and hemicellulose are the basic structural material of the wood cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

s; lignin acts as a kind of cell-bonding glue. Some softwood

Softwood

The term softwood is used to describe wood from trees that are known as gymnosperms.Conifers are an example. It may also be used to describe trees, which tend to be evergreen, notable exceptions being bald cypress and the larches....

s, especially pine

Pine

Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

s and fir

Fir

Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...

s, hold significant quantities of resin

Resin

Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...

, 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

Caramelization

Caramelization is the browning of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. As the process occurs, volatile chemicals are released, producing the characteristic caramel flavor....

, producing carbonyl

Carbonyl

In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups....

s, which provide most of the color components and sweet, flowery, and fruity aromas. Lignin, a highly complex arrangement of interlocked phenolic

Phenols

In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group bonded directly to an aromatic hydrocarbon group...

molecules, also produces a number of distinctive aromatic elements when burnt, including smoky, spicy, and pungent compounds such as guaiacol

Guaiacol

Guaiacol is a naturally occurring organic compound with the formula C6H4. Although it is biosynthesized by a variety of organisms, this colorless aromatic oil is usually derived from guaiacum or wood creosote. Samples darken upon exposure to air and light. Guaiacol is present in wood smoke,...

, phenol

Phenol

Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...

, and syringol

Syringol

Syringol is a dimethyl ether of pyrogallol. It is slightly soluble in water. It is combustible, with flash point of 140 °C.Together with guaiacol, syringol and its derivates are characteristic products of pyrolysis of lignin. As such, syringol is an important component of wood smoke...

, and sweeter scents such as the vanilla

Vanilla

Vanilla is a flavoring derived from orchids of the genus Vanilla, primarily from the Mexican species, Flat-leaved Vanilla . The word vanilla derives from the Spanish word "", little pod...

-scented vanillin

Vanillin

Vanillin is a phenolic aldehyde, an organic compound with the molecular formula C8H8O3. Its functional groups include aldehyde, ether, and phenol. It is the primary component of the extract of the vanilla bean. It is also found in Leptotes bicolor, roasted coffee and the Chinese red pine...

and clove

Clove

Cloves are the aromatic dried flower buds of a tree in the family Myrtaceae. Cloves are native to the Maluku islands in Indonesia and used as a spice in cuisines all over the world...

-like isoeugenol

Isoeugenol

Isoeugenol is a phenylpropene, a propenyl-substituted guaiacol. A phenylpropanoid, it occurs in the essential oils of plants such as ylang-ylang . It can be synthesized from eugenol and had been used in the manufacture of vanillin. It may occur as either the cis or trans isomer...

. 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 protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, 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 antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

s, which slow rancidification

Rancidification

Rancidification is the chemical decomposition of fats, oils and other lipids . When these processes occur in food, undesirable odors and flavors can result. In some cases, however, the flavors can be desirable . In processed meats, these flavors are collectively known as "warmed over flavor"...

of animal fats, and antimicrobials, which slow bacterial growth. Other antimicrobials in wood smoke include formaldehyde

Formaldehyde

Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...

, acetic acid

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

, and other organic acids, which give wood smoke a low pH

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

—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 (298.9 and 398.9 C). 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

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

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 liquid smoke

Liquid Smoke

Liquid smoke is a substance produced from smoke passed through water. Liquid smoke is used for both food preservation and flavoring. While some worry that liquid smoke contains carcinogenic compounds, research suggests that the concentration levels are well under the acceptable limit formed by the...

).

In the past, smoking was a useful preservation tool, in combination with other techniques, most commonly salt-curing

Curing (food preservation)

Curing refers to various food preservation and flavoring processes, especially of meat or fish, by the addition of a combination of salt, nitrates, nitrite or sugar. Many curing processes also involve smoking, the process of flavoring, or cooking...

or drying

Drying (food)

Drying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times, and was the earliest form of food curing...

. 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 rancidification

Rancidification

. (Interior fat is not as exposed to oxygen

Oxygen

, 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
Lapsang souchong
Lapsang souchong is a black tea originally from the Wuyi region of the Chinese province of Fujian. It is sometimes referred to as smoked tea...

tea
Tea
Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...

leaves are smoked and dried over pine or cedar fires
Malt
Malt
Malt is germinated cereal grains that have been dried in a process known as "malting". The grains are made to germinate by soaking in water, and are then halted from germinating further by drying with hot air...

beverages
- The malt used to make whisky
  Whisky
  Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Different grains are used for different varieties, including barley, malted barley, rye, malted rye, wheat, and corn...
- Rauchbier (smoked beer)

Fruit and vegetables

Capsicum
Capsicum
Capsicum is a genus of flowering plants in the nightshade family, Solanaceae. Its species are native to the Americas where they have been cultivated for thousands of years, but they are now also cultivated worldwide, used as spices, vegetables, and medicines - and have become are a key element in...

s: chipotle
Chipotle
A chipotle , or chilpotle, which comes from the Nahuatl word chilpoktli meaning "smoked chili pepper" is a smoke-dried jalapeño that tends to be brown and shriveled. It is a chili used primarily in Mexican and Mexican-inspired cuisines, such as Mexican-American and Tex-Mex.Varieties of jalapeño...

s (smoked, ripe jalapeño
Jalapeño
The jalapeño is a medium-sized chili pepper that has a warm, burning sensation when eaten. A mature jalapeño fruit is 2–3½ inches long and is commonly picked and consumed while still green, but occasionally it is allowed to fully ripen and turn crimson red...

peppers
Chili pepper
Chili pepper is the fruit of plants from the genus Capsicum, members of the nightshade family, Solanaceae. The term in British English and in Australia, New Zealand, India, Malaysia and other Asian countries is just chilli without pepper.Chili peppers originated in the Americas...

), paprika
Paprika
Paprika is a spice made from the grinding of dried fruits of Capsicum annuum . In many European languages, the word paprika refers to bell peppers themselves. The seasoning is used in many cuisines to add color and flavor to dishes. Paprika can range from mild to hot...
Prunes (dried plums) can be smoked while drying
Wumei are smoked plum fruits
Iburi-gakko are a smoked daikon
Daikon
Daikon , Raphanus sativus var. longipinnatus, also called White Radish, Japanese radish, Oriental radish, Chinese radish, lo bok and Mooli , is a mild flavoured, very large, white East Asian radish...

pickle
Pickle
Pickling is a process of preserving food. Pickle or pickling may refer to:-Food:* Pickled cucumber* Pickled onion* Pickled herring* Indian pickle includes oil-based food preservation* Branston and similar sweet pickle relishes...

from Akita Prefecture
Akita Prefecture
is a prefecture of Japan located in the Tōhoku Region of northern Honshu, the main island of Japan. The capital is the city of Akita.- History :The area of Akita has been created from the ancient provinces of Dewa and Mutsu....

, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...