Stockfish is unsalted fish, especially cod, dried by cold air and wind on wooden racks on the foreshore, called "hjell". The drying of food is the world's oldest known preservation method, and dried fish has a storage life of several years. The method is cheap and effective in suitable climates; the work can be done by the fisherman and family, and the resulting product is easily transported to market.
Over the centuries, several variants of dried fish have evolved. The stockfish (fresh dried, not salted) category is often wrongly mixed with the clipfish, or salted cod, category where the fish is salted before drying. After 2–3 weeks in salt the fish has salt-matured, and is transformed from wet salted fish to clipfish through a drying process. The salted fish was earlier dried on rocks (clips) on the foreshore. The production method of clipfish (or Bacalhau in Portuguese) was developed by the Portuguese who first mined salt near the brackish water of Aveiro, and brought it to Newfoundland where cod was available in massive quantities. (q.v.). Salting was not economically feasible until the 17th century, when cheap salt from southern Europe became available to the maritime nations of northern Europe.
Stockfish is cured in a process called fermentation where cold-adapted bacteria matures the fish, similar to the maturing process of cheese. Clipfish is processed in a chemically curing process called salt-maturing, similar to the maturing processes of other salt-matured products like Parma ham.
The word stockfish is a loan word from Dutch stokvis (stick fish), possibly referring to the wooden racks on which stockfish are traditionally dried or because the dried fish resembles a stick. "Stock" may also refer to a wooden yoke or harness on a horse or mule, once used to carry large fish from the sea or after drying/smoking for trade in nearby villages. This etymology is consistent with the fact that "Stockmaß" is German for the height of a horse at the withers. "Stockfish" and "Stockmaß" therefore refer essentially to the same basic length.
Stockfish is Norway's longest sustained export commodity, and the socioeconomically most profitable export over the centuries. Stockfish is first mentioned as a commodity in the Icelandic saga "Egilssaga", when the Chief Torolv Kveldulvssøn in year 875 AD, shipped stockfish from Helgeland in mid Norway to Britain. This product represented most of Norway's national income from Viking age throughout medieval age.
Stockfish is extremely popular and is widely consumed in Catholic Mediterranean countries, notably Italy. (Stockfish is called stoccafisso in most Italian dialects, but confusingly baccalà—which normally refers to salt cod—in the Veneto).
Manufacturing and usage 
The science of producing good stockfish is in many ways comparable to that of making a good cognac, Parma ham, or a well matured cheese. The Slow Food movement insists that all these artisanal products must be made on a small scale and given time to mature.
The fish is prepared immediately after capture. After gutting the fish, it is either dried whole, or split along the spine leaving the tail connected. The fish is hung on the hjell from February to May. Stable cool weather protects the fish from insects and prevents an uncontrolled bacterial growth. A temperature just above zero degrees Celsius, with little rain, is ideal. Too much frost will spoil the fish, as ice destroys the fibers in the fish. The climate in northern Norway is excellent for stockfish production. Due to the stable conditions, the stockfish produced in Lofoten is regarded as the best. The traditional cod harvest in Lofoten also takes place during the best drying time. Due to a milder and more humid climate, salted/dried whitefish (klippfisk) was more common in the fisheries districts of Western Norway.
After its three months hanging on the hjell, the fish is then matured for another two to three months indoors in a dry and airy environment. During the drying, about 80% of the water in the fish evaporates. The stockfish retains all the nutrients from the fresh fish, only concentrated: it is therefore rich in proteins, vitamins, iron, and calcium.
After sorting by quality, most of the stockfish is exported to Italy, Croatia and Nigeria. In Norway and Iceland, the stockfish is mostly used as a snack and for lutefisk production. In Italy, the fish (called stoccafisso) is soaked and used in various courses, and is viewed as a delicacy.
The baccalà alla vicentina, an ancient and traditional Italian dish native to Vicenza, is made from stockfish (confusingly not from salt cod, although salt cod is known in standard Italian as baccalà) and is served on or next to polenta. Dishes made from stockfish (locally called bakalar) are traditionally eaten on Christmas Eve in Croatia, especially Dalmatia.
Stockfish is popular in West Africa, where it is used in the many soups that complement the grain staples fufu and garri. Also the main ingredient in the Igbo snack called "Ugba na Okporoko". The Bakweri, who are a fishing people of the English-speaking part of Cameroon, use stockfish in flavoring their palm nut or banga soup, which is eaten with a cocoyam pudding called kwacoco. The name okporoko for stockfish, among the Igbo of Nigeria refers to the sound the hard fish makes in the pot and literally translates as "that which produces sound in the pot".
Both stockfish and salt cod can be made into lutefisk.
Stockfish is typically sold in whole bales (100 lbs per bale) or half-a-bale, one-quarter bale or even one-tenth-bale.
Stockfish up for drying in Iceland
Stomach of a sea lion used by Aleut natives to store dried red salmon
See also 
- Kurlansky, chapter 3; cf. OED s.v. 'stockfish': "the reason for the designation is variously conjectured"
- Kurlansky, chapter 9
- Kurlansky, chapter 2
|Wikimedia Commons has media related to: Stockfish|
- Kurlansky, Mark (1997). Cod: A Biography of the Fish That Changed the World. New York: Walker. ISBN 0-8027-1326-2.