Smoking is an ancient method of food preservation that is still practiced because it adds an interesting flavor to meat, fish, poultry, and other foods; allows foods such as hams to be stored at room temperature; and slightly dries and preserves some foods, such as sliced salmon, that are eaten raw.
Smoking dates back centuries, especially for fish, which is highly perishable. Archeological evidence suggests that ninth-century residents of Poland smoked large quantities of fish (Shephard, p. 117). In medieval Europe, the religious practice of avoiding meat on certain days created a tremendous demand for fish, and enormous quantities of salmon and herring were salted and smoked in seaside towns before being shipped to the interior. Pork was also a popular meat for smoking since pigs were slaughtered in the fall and their meat could be preserved on the farm to last through the winter. Smoked pork was found in China as well as Europe. In South America, long strips of dried meat are called charqui, which has come into English as "jerky" as the name for a snack made from beef or turkey.
Smoking is a preservative because smoke contains chemical compounds that retard the growth of harmful bacteria. More than three hundred components of smoke have been identified. Carbonyl compounds in smoke contribute to the distinctive flavor and aroma of smoked meat, while the carbon dioxide and carbon monoxide help produce the bright red pigment. Phenolic compounds in smoke play a role in protecting fat from oxidizing and turning rancid, which is no doubt a major reason why fatty foods, such as herring or pork, were (and are) so often smoked. The composition of the smoke changes as the temperature of the fire rises, with the best quality smoke produced at a temperature of 650° to 750°F. Control of humidity in the smokehouse is also important since high humidity favors deposition of smoke on the surface of the food and absorption of the flavor. High humidity also assists in the rendering of fat.
Smoking operations fall into two categories: hotsmoking and cold-smoking. In hot-smoking, the temperature in the smoke chamber ranges from 120° to 180°F, which produces a strong smoky flavor. However, the meat is usually only partially cooked and must be finished in a conventional oven. In cold-smoking, the smoke is produced in a firebox but allowed to cool before being passed into the smoking chamber, where the temperature is a mere 70° to 90°F. The food is hardly cooked at all, but long exposure to cool smoke gives the food a mild, smoky flavor and dries it to some extent. Cold-smoking is used largely for foods that will be eaten raw, such as smoked salmon or smoked fillet of beef. The temperature range from 90° to 120°F is considered too hot for cold-smoking and too cool for hot-smoking. A temperature over 180°F is considered "cooking with smoke" rather than smoking as such; pork barbecue and regional dishes such as Texas beef brisket are in this category. A great variety of foods can be successfully cold-smoked or hot-smoked, ranging from fish to pork, poultry, and beef to wild game.
Many foods are cured before smoking, especially cold-smoking, to draw out the moisture, which would otherwise promote spoilage. The cure is a mixture of salt, sodium nitrate, nitrites, sometimes sugar, spices, and other seasonings, and additives such as phosphates or ascorbates. Nitrate and nitrites contribute to the flavor and coloration of products such as ham. Nitrite and salt inhibit the growth of Clostridium botulinum, the bacterium that causes botulism.
A dry cure can be applied by rubbing the meat with the mixture or packing the food in a container of the cure mix and letting it sit for several days or weeks. A wet cure can be applied through a brine of water or other liquid containing the cure ingredients; brine can also be injected into the food in order to impregnate its center and speed up the curing process. Once cured, the food is dried and smoked.
Some items, such as hams, are hung for weeks or months under conditions of controlled temperature and humidity to develop flavor. Humidity is controlled by the addition of steam or water vapor as well as the use of dampers. Air movement is also critical to uniform heating, curing, and flavor in the final product. High air velocities tend to produce more rapid drying and a firm consistency.
Home units for hot-smoking are typically upright cylinders with an electric hot plate, charcoal grate, or gas range at the bottom to produce heat; wood is placed over the heat source to create smoke, and the food is placed on a rack above the wood. A pan of water is often placed in the smoker to catch the drippings from the food so that they do not fall into the heat source and cause flareups. The more elaborate units include adjustable baffles and other controls to allow the cook to control the smoke. Double-chamber units for both hot-and cold-smoking are usually horizontal and tend to be rather large and heavy.
Different types of wood are used to produce different flavors in the smoke. Hickory is a great favorite in the eastern United States, while alder is popular in the Pacific Northwest. Maple, oak, and pecan are also used in the United States. In Scotland, peat fires were once used to smoke fish. Beech, oak, and chestnut are the most popular woods in Europe. Commercial operations use sawdust or logs, while most home smokers use wood chips set in a pan on the heating element; the large, dual-chamber home smokers can use small logs. Evergreens are usually avoided because they contain resins that can produce a sticky smoke and impart a bitter flavor to the food. However, resinous wood is sometimes used at the end of the smoking process to give the outside of the food a protective coating. No matter what fuel is used, a smoldering fire is preferred to an open flame because it produces abundant smoke and avoids very high temperatures.
Smoked salmon, usually sliced very thin, is an elegant dish. It is cold-smoked and eaten raw. Lox (from the Yiddish word for smoked salmon) is usually more heavily cured than other types and is often eaten on a bagel with cream cheese. Kippers are cured and smoked herrings, still very popular in Britain at breakfast, lunch, or tea. The village of Findon in Scotland gave its name to smoked haddock (finnan haddie), which is served hot after being broiled or poached. Halibut, sturgeon, and fish roe (eggs) are also cold-smoked. Eel, trout, and mackerel are hot-smoked and can be eaten without further cooking.
A whole ham is the hind leg of a pig. Many regions in the United States and Europe have particular styles of ham production and preparation. "Country ham" from Virginia, Tennessee, or Kentucky, for example, is heavily cured and smoked for weeks or months over smoldering fires of hickory or apple wood. The resulting ham is so dry and hard that it must be soaked overnight to get rid of some of the salt, and then boiled to soften it. Britain produces the York ham, popular for boiling, the Suffolk ham, cured with spices and honey, and the Bradenham, which is cured with molasses. Prague ham (from Czechoslovakia) is lightly smoked over beechwood coals and is said to be among the sweetest of hams. Many hams are smoked but eaten raw, such as Westphalian ham from Germany. (Prosciutto ham from Parma, Italy, is also raw but is not smoked).
Smoking also gives meat its distinctive reddish color. Sausages are often smoked, as are frankfurters. In the United States, bacon is usually smoked and often cured with sugar to give it a sweet taste.
Chickens, turkey, duck, and geese can be hotsmoked, usually after being cooked, and the resulting meat tastes like ham. Smoked poultry, however, is perishable and must be kept frozen or refrigerated until it is reheated or served cold. Boneless beef roast can be hotsmoked for several hours to the desired temperature and sliced very thin.
Nearly any type of game can be smoked, from squirrel meat to bear and wild boar. Hunters should ensure that game meats are properly handled and cooked to at least 180°F to eliminate the danger of botulism or trichinosis.
Bibliography
Terence Conran, Caroline Conran, and Simon Hopkinson. The Essential Cook Book: The Back-to-the-Basics Guide to Selecting, Preparing, Cooking, and Serving. New York: Stewart, Tabori and Chang, 1997.
McGee, Harold. On Food and Cooking: The Science and Lore of the Kitchen. New York: Simon and Schuster, 1997. Originally published by Charles Scribner's Sons, 1984.
Park, Lue, and Ed Park. The Smoked-Foods Cookbook: How to Flavor, Cure and Prepare Savory Meats, Game, Fish, Nuts, and Cheese. Harrisburg, Pa.: Stackpole, 1992.
Shephard, Sue. Pickled, Potted, and Canned: How the Art and Science of Food Preserving Changed the World. New York: Simon and Schuster, 2001.
—Richard L. Lobb Francis McFadden
