CANNING OF FISH AND FISH PRODUCTS 449 



cans are inverted on wire mesh racks and cooked in retorts with Hve steam for 

 45 minutes at 3-pounds pressure. After draining for about 30 minutes the cans 

 are reversed, the backbones of the fish removed, the cans repacked, and about 

 /2-ounce cottonseed or other vegetable oil added. The cans are exhausted for 

 about 10 minutes at 212° F (100° C), and then sealed and processed 1% hours 

 at 240° F (116° C), or 2 hours at 230° F (110° C). 



Herring. Large herring are canned plain or kippered to some extent in Maine, 

 on the Pacific Coast, and in Great Britain, the methods used being similar in the 

 three localities. Other canned herring products are put up in European countries 

 bordering the North Sea. 



In Maine herring running 10 inches or more in length are used for plain canned 

 herring. The fish are beheaded, dressed, and held in strong pickle (from 70 to 

 80° Sal.) for about 1 hour. They are then packed vertically in tall 1-pound cans 

 and steamed in retorts 30 minutes at 230° F (110° C). After being sealed hot 

 they are processed 2 hours at 240° F (116° C). 



Kippered Herring. The fish are dressed and pickled in brine as for plain herring. 

 They are next strung through the tails on wooden rods of about /2 X /2 X 24 inches, 

 through which long nails are driven a few inches apart. The rods are placed close 

 together in horizontal rows on frames built in a smokehouse, and these rows ex- 

 tend one above the other to the top of the building and to within about 6 feet 

 of the floor. The fish are exposed for 18 to 24 hours to the smoke and heat from 

 a smoldering fire of birch or other hard wood which dries them and gives them 

 the slightly smoky flavor desired. The fish are then removed and packed by 

 hand in 1 -pound oval cans. The cans are sealed without further addition and are 

 processed in a bath of boiling water for about 2/2 hours. 



Marinated Fish. Bismarck herring are prepared by washing choice herring of 

 uniform size in a revolving cylindrical screen, which also removes the scales. The 

 fish are then dressed by removing heads, tails, and bones by hand, and rinsed 

 and placed in about 75° brine for 2 or 3 hours. From the brine tanks they 

 are transferred to a vinegar pickle of 5 to 6 per cent acidity, containing con- 

 siderable salt. After about 2 days the fish are ready to pack in cans, in which 

 they are placed in layers, with onions, peppers, and mustard seed on each layer. 

 A small amount of 2/4 per cent vinegar and a little sugar are added to each can, 

 which is exhausted, sealed, and processed. 



Rollmops. These are prepared by spreading the boned and pickled herring on 

 a table and rolling each piece around a salted cucumber pickle or onion. The 

 rolls are fastened with wooden pins, packed in cans, and after peppers, allspice, 

 mustard seed, bay leaf, paprika, a slice of pickle, and a little vinegar are added, 

 the can is exhausted, sealed, and sterilized. 



The preparation of marinated fish, rollmops, and other miscellaneous products 

 is described in greater detail in Chapter 21. 



Shad. Shad is so highly esteemed in the fresh state and the supply on the 

 Atlantic Coast has been so limited in recent years that it is not canned there. 

 This fine food fish was introduced on the Pacific Coast about 50 years ago and has 

 become well established in the Sacramento and Columbia rivers, where it is 

 caught to a limited extent by the salmon fishermen when salmon are not plenti- 

 ful, and is canned by a few of the salmon canners. 



The fish are scaled, split, and dressed. After thorough cleaning they are cut 



