CURED FISHERY PRODUCTS 329 



Conditioned air dryers, which are now in operation in a large part of 

 the North American salt fish industry, consist of tunnel-type dryers in 

 which the salt fish is spread on wire mesh trays and dehumidified air 

 blown across the fish at a temperature of about 80°F and at a velocity of 

 about 300 to 400 feet per minute. The air is dehumidified either by first 

 cooling it or sometimes by a chemical process. The relative humidity 

 of the air during drying is adjusted to about 50 per cent or slightly less. 

 Heavily salted fish which are to be reduced to about 43 per cent moisture 

 content can be dried in from 30 to 60 hours, depending upon the size 

 of the fish. With larger fish two or three drying periods of about 20 hours 

 may be interspersed with waterhorsing (press piling). 



Yields and Salt Content. Beatty and Fougere^ report that the salt con- 

 tent of salt cod varies from 4 per cent for a very lightly salted product 

 with a curing time of 2 days to 20 per cent for a heavily salted product 

 cured for about 21 days. The lightly salted cod will have about 74 per 

 cent moisture content and are subsequently dried to about 35 per cent 

 moisture. The loss of weight during salting is about 17 per cent. The 

 heavily cured cod will have a moisture content of about 57 per cent before 

 drying and a loss in weight of about 30 per cent. The heavily cured salt 

 cod is generally dried to about 40 per cent moisture content. One hundred 

 pounds of split cod will yield about 49 pounds of heavily cured dried 

 product. 



Brine Pack Process. In the brine pack process which is used for salt 

 preservation of various oily fish such as herring and salmon, the fish are 

 kept beneath the surface of brine until they are used. This helps to mini- 

 mize oxidation of the oils in such fish by keeping oxygen away to a large 

 extent. 



Principal species of fish which are salted by the brine pack process in 

 the United States are salmon (mild cured) and lake herring. The river 

 herring, although cured in brine, are eventually packed as a dry salt 

 product and should be so classifieds The production of mild cured salmon, 

 an intermediate product preliminary to smoking, has been discussed 

 briefly in the chapter on the salmon fisheries. The production methods 

 for brine packed lake herring will be described briefly here. For greater 

 detail concerning brine pack methods the reader is referred to JarvisS 



The lake herring are salted principally in Wisconsin and Michigan. 

 The fish are cleaned and dressed, including beheading, upon arrival at 

 the shore plant. They are then thoroughly washed in a tank of water 

 and drained. The fish are salted by rubbing them with dry salt and pack- 

 ing in kegs (half-barrels of 125 pound capacity). The lake herring are 

 packed belly side up in layers of about 25 fish with dry salt between layers. 

 The barrel is filled to about four inches above the top to allow for initial 



