In nearly all instances where tobacco is to be used for smoking or chewing, it is necessary to

cure A cure is a substance or procedure that ends a medical condition, such as a medication, a surgical operation, a change in lifestyle or even a philosophical mindset that helps end a person's sufferings; or the state of being healed, or cured. The ...

the

tobacco Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...

directly after it's harvested. Tobacco curing is also known as ''color curing'', because tobacco leaves are cured with the intention of changing their color and reducing their

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to ...

content.

History

Curing tobacco has always been a process necessary to prepare the leaf for consumption because, in its raw, freshly picked state, the green tobacco leaf is too wet to ignite and be smoked. In recent times, traditional curing barns in the United States have been falling into disuse, as the trend toward using prefabricated metal curing boxes has become more and more prevalent. Temporary curing boxes are often found on location at tobacco farms.

Processes

Curing and subsequent aging allow for the slow oxidation and degradation of

carotenoids Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, co ...

in the tobacco leaf. This produces various compounds in the tobacco leaves that give cured tobacco its sweet hay, tea, rose oil, or fruity aromatic flavor that contributes to the "smoothness" of the consumed product. Non-aged or low quality tobacco is often artificially flavored with these otherwise naturally occurring compounds. Tobacco flavoring is a significant source of revenue for the flavor and fragrance industry. The aging process continues for a period of months and often extends into the post-curing harvest process. After tobacco is cured, it is moved from the curing barn into a storage area for processing. If whole plants were cut, the leaves are removed from the tobacco stalks in a process called stripping. For both cut and pulled tobacco, the leaves are then sorted into different grades. In colonial times, the tobacco was then "prized" into

hogshead A hogshead (abbreviated "hhd", plural "hhds") is a large cask of liquid (or, less often, of a food commodity). More specifically, it refers to a specified volume, measured in either imperial or US customary measures, primarily applied to alco ...

s for transportation. In brightleaf tobacco regions, prizing was replaced by stacking wrapped "hands" into loose piles to be sold at auction. Today, most cured tobacco is baled before sales are made under pre-sold contracts.

Methods

Cut plants or pulled leaves are immediately transferred to

tobacco barn The tobacco barn, a type of functionally classified barn found in the USA, was once an essential ingredient in the process of air- curing tobacco. In the 21st century they are fast disappearing from the landscape in places where they were once ub ...

s (kiln houses), where they will be cured. Curing methods vary with the type of tobacco grown, and tobacco barn design varies accordingly, including the newer use of field-side curing frames.

Air

''Air-cured'' tobacco is hung in well-ventilated barns and allowed to dry over a period of four to eight weeks. Air-cured tobacco is low in sugar, which gives the tobacco smoke a light, sweet flavor, and a high nicotine content. Cigar and burley tobaccos are air cured.

Fire

''Fire-cured'' tobacco is hung in large barns where fires of hardwoods are kept on continuous or intermittent low smoulder and takes between three days and ten weeks, depending on the process and the tobacco. Fire curing produces a tobacco low in sugar and high in nicotine. Pipe tobacco, chewing tobacco, and snuff are fire cured.

Flue

''Flue-cured'' tobacco was originally strung onto tobacco sticks, which were hung from tier-poles in curing barns (Aus:

kiln A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...

s), also traditionally called oasts. These barns have flues which run from externally fed fire boxes, heat-curing the tobacco without exposing it to smoke, slowly raising the temperature over the course of the curing. In the 1960s conversion to gas fueled systems such as the Gastobac Burner System® was common. The process will generally take about a week. This method produces tobacco that is high in sugar and has medium to high levels of nicotine. The Smith Tobacco Barn is an example of a traditional, flue-cured tobacco barn. Flue-cured tobacco requires an estimated one tree per 300 cigarettes.

Sun

Sun-curing tobacco involves simply drying the leaves uncovered in the sun until they are brown and withered. This method is predominantly used in

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Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders wi ...

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...

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Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

and throughout the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

basin to produce oriental tobacco, however sun-cured tobacco is also produced in India and Africa as well. Oriental sun-cured tobacco is low in both sugar and nicotine but fragrant, herbal, and spicy. It is prized among pipe tobacco blenders for this quality. In

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

, sun-curing is used to produce so-called "white" snuff from varieties of burley. The sun-cured burley tobacco is very finely milled into a dry powder, and unusually potent.

Fermentation

Some tobaccos such as

Cavendish Cavendish may refer to: People * The House of Cavendish, a British aristocratic family * Margaret Cavendish (1623–1673), British poet, philosopher, and scientist * Cavendish (author) (1831–1899), pen name of Henry Jones, English au ...

and Perique are subjected to a second stage of curing known as

fermenting Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food p ...

or sweating. Cavendish tobacco undergoes a process of fermentation under great pressure (often in a large press) and steam. Before being steamed, it is "cased" in a solution which mainly consists of sugar, but can sometimes include flavorings. Perique is special in its process of fermentation, as after it is air-cured, it is traditionally fermented under enormous pressure (via large weights or a hydraulic press) for several months to a year. The process produces a very strong tobacco in both flavor and nicotine, and is prized by pipe tobacco blenders for its uniquely peppery and savory flavors and aromas.

References

{{Authority control Tobacco