Information about Smoking (cooking)

Smoking is the process of flavouring, cooking, or preserving food by exposing it to the smoke from burning or smoldering plant materials, most often wood. Meats and fish are the most common smoked foods, though cheeses, vegetables, and ingredients used to make beverages such as whisky,^[1] Rauchbier, and lapsang souchong tea are also smoked.

In Europe, alderwood 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 fuels 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 corn cobs. Peat is burned to dry and smoke the barley malt used to make whisky and some beers.

Historically, farms in the western world included a small building termed the smokehouse 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. The buccan is a smoking device used by some Native Americans.

Hot smoking and cold smoking

"Hot smoking" is a several-hours-long process that can be used to fully cook meats or fish; barbecue is a form of hot smoking. Generally, hot-smoking involves holding the food directly above the fire, or in an enclosure that is heated by the fire. The cooking temperature in a hot-smoking environment is usually between 180 and 250°F (55 to 80°C). The temperatures reached in hot smoking can kill microbes throughout the food.

"Cold smoking" is an hours- or days-long process in which smoke is passed by food which is held in a separate area from the fire. Generally the food is held at room temperatures (60–80°F/15–25.5°C) as it is smoked. Since no cooking takes place, the interior texture of the food generally isn't affected; neither are any microbes living within the meat or fish. For this reason, cold-smoking has traditionally frequently been combined with salt-curing, in such foods as Gouda cheese, ham, bacon, and cold-smoked fish like lox (smoked salmon).

Wood smoke

Hardwoods 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. Because of this, these woods are generally not used for smoking.

Cellulose and hemicellulose are aggregate sugar molecules; when burnt, they effectively caramelize, producing sweet, flowery, and fruity aromas. Lignin, a highly complex arrangement of intelocked phenolic molecules, also produces a number of distinctive aromatic elements when burnt, including smoky, spicy, and pungent compounds like guaiacol, phenol, and syringol, and sweeter scents like the vanilla-scented vanillin and clove-like isoeugenol. Guaiacol is the phenolic compound most responsible for the "smokey" taste, while syringol is the primary contributor to smokey aroma. (Hui 512) 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. The compounds best demonstrated to have long-term health consequences are the polycyclic aromatic hydrocarbons, or PAHs, many of which are known or suspected carcinogens. Hotter wood fires make more PAHs; hot-burning mesquite produces twice as much as cooler-burning hickory.

Since different species of tree 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 (300–400 °C). This is the temperature of the burning wood itself, not of the smoking environment, which sees 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 lowered by soaking the pieces in water before placing them on a fire.

Preservation

Smoke is a decent antimicrobial and antioxidant, but smoke alone is insufficient for preserving food in practice. The main problem is that the smoke compounds adhere only to the outer surfaces of the food; smoke doesn't actually penetrate far into meat or fish. In modern times, almost all smoking is carried out for its flavor, not its preservative qualities.

In the past, smoking was a useful preservation tool, in combination with other techniques, most commonly salt-curing or drying. 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. (Interior fat isn't as exposed to 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 required a treatment such as boiling in fresh water to make them palatable before eating.

Some smoked foods and drinks

• Fish
• Lox
• Smoked salmon
• Kippers
• Arbroath Smokies (haddock)
• Many pork products are cured and smoked
• Ham
• Bacon
• Pastrami, pickled, spiced and smoked beef brisket
• Various sausages
• Traditionally-prepared jerky
• The malt used to make whisky
• Rauchbier
• Lapsang souchong tea leaves are smoked and dried over pine or cedar fires
• Prunes, which are dried plums, can be obtained through smoking
• Wumei are smoked ume fruit
• Chipotles are smoked jalapeño peppers
• Smoked Cheeses, such as smoked gouda
• Smoked salt
• Smoked paprika

Other home food preservation methods

• Pickling
• Canning
• Drying (food)

•  • [ e] Cooking Techniques
Cooking under heat	Baking Frying Deep-frying Boiling Braising Grilling/Broiling Roasting Sauting Stir frying Poaching Parboiling Steaming Pressure cooking Pressure frying Simmering
Cooking without heat	Smoking Marination
Food preservation	Canning Drying Pickling Refrigeration Salting Smoking
Par-cook	Blanching
Other Techniques	Creaming Fermenting Outdoor cooking Scalding Tempering

References

• McGee, Harold (2004). On Food and Cooking (Revised Edition). Scribner. ISBN 0-684-80001-2.  pp 448-450, "Wood Smoke and Charred Wood"
• Hui, Y.H. (2001). Meat Science and Applications. Marcel Dekker. ISBN. 

Notes

External links

• National Center for Home Food Preservation - How Do I...Cure & Smoke