118 tr. S. BUREAU OF FISHERIES. 



is manufactured. The cans then leave the machine on an endless 

 conveyer, pass through a machine which washes the outside of the 

 cans, and thence to the men who transfer them to the coolers, which 

 are immediately placed upon the trucks and run into the retort for 

 the one cooking they are to receive. By the use of these cans the 

 soldering machine used in the old-style method is done away with. 

 It also does away with the first cooking and the subsequent venting 

 and soldering, a saving both in labor and time consumed. 



COOKING. 



The processing time varies in each district and sometimes for each 

 species. In Alaska 1 -pound tall reds, cohos, chums, and pinks are 

 generally cooked from 90 to 120 minutes, at 12 to 18 pounds pressure 

 and at a temperature of 242° to 248° F. One-pound flats and half- 

 pound cans are generally cooked about 10 minutes less time. Owing 

 to their larger bones, king salmon are generally cooked from 10 to 20 

 minutes longer than the other species; steelhead trout also. 



On Puget Sound 1 -pound tall sockeyes, cohos, and pinks are gener- 

 ally cooked for 90 minutes at a pressure of 10 pounds and at a tem- 

 perature of 240° F. Halves and 1-pound flats are generally cooked 

 at the same temperature but for only 80 minutes. Chum tails are 

 generally cooked for 105 minutes at a pressure of 10 pounds and at 

 a temperature of 240°; while spring or king salmon are cooked for 

 120 mmutes at a pressure of 10 pounds and at a temperature of 240°. 



It is the custom at all canneries, no matter what the system, to 

 allow about 5 minutes at the beginning of the cooking to work up 

 the required heat of the retort, and when cooking is completed there 

 is a like period for reducing the temperature and pressure before 

 opening the doors. The cooking times given above are exclusive of 

 the two 5-niinute periods noted here. 



It should be distinctly understood that the processing times noted 

 are only approximate. The condition of the fish, the weather — 

 whether hot or cold, rainy or dry — etc., all must be taken into account. 

 The canner can not go far astray, however, if he keeps generally 

 within the narrow margins noted above. In the early days much 

 secrecy and mystery was thrown about the cooking, and the work 

 was carried on in a separate room, known as the "bathroom," 

 under lock and key. The first cooking was done in common tubs. 

 The early retorts were made of wood. Later, round iron kettles 

 were substituted, nearly one-half consisting of cover, and round 

 crates were used for holding the cans. At the present time only 

 rectangular horizontal iron or steel retorts are used, and access to 

 these is had by means of miniature railroad tracks. 



For many years cannery men believed that the double cooking of 

 salmon was absolutely necessary, but in 1898 F. A. Seufert, at his 

 cannery on the Columbia lliver, at Seuferts, Oreg., a short (listance 

 above The Dalles, discarded this idea, and has since used a one- 

 cooking method. By the new process the cans arc tested for leaks 

 after the center hole in the top is soldered up, as before, and are left 

 in the retort 70 minutes at 245° F. and 12 pounds steam pressure. 

 According to its originator, this method saves more than one-half 

 the labor in the batliroom, saves nearly one-half the labor in washing 

 the cans after cooking, and also better retains the color of the fish. 



