FISHERY INDUSTRIES OF THE UNITED STATES. 15 



Experiments made in salting fish of various degrees of staleness showed that the 

 length of time a fish may be kept before salting depends upon the temperature to 

 which, the fish are subjected before and during the salting period, and that at some 

 temperature between 50 and 60° F.. or higher, fish spoil very quickly. 



The following are important considerations in the salting of fish in warm climates: 

 All \iscera and blood should be removed in cleaning, large fish should be split, the 

 fish salted should be in a fresh condition, no brine should be added, and salts low in 

 calcium should be selected. 



At the close of the year plans were being perfected for the practical 

 application on a somewhat larger scale of the results obtained in 

 these small-scale laboratory experiments to determine more definitely 

 the manner in which these results may be applied with profit to the 

 industry. These plans include the salting of river herring at points 

 in Florida where usual practices hare previously proved a failure. In 

 addition to the work outlined above, some attention has been given 

 to the chemical changes in the fat content of fish. 



FREEZING FISH IN BRINE. 



Refrigeration as a means of preserving fish promises to play an 

 increasingly more important role in the fishing industry. In this 

 connection th(>rc exists a fencing that more of our energies hitherto 

 expended in perfecting refrigeration machinery and methods should 

 be applied to effecting improvements in the quality of the product 

 and in educating the consumer to its merits, its care, and preparation. 

 In Europe the process of freezing fish in brine has of late been re- 

 ceiving considerable attention, and the use of the method is increas- 

 ing. Brief mention of the subject may therefore be of interest to 

 those engaged in the industry in this country. 



Fundamentally the process consists of immersing the article to be 

 frozen in a strong brine which has previously boon cooled to, or nearly 

 to, the point where mush ice begins to form in the solution. That the 

 freezing temperature of brine is lower than that of water and that 

 the freezing temperature of the brine is lowered as its saturation 

 point is approached is well known. At present there are at least two 

 processes employing the brine method, one known as the Dahl 

 method, originated by Nekolai Dahl at Trondhjem, Norway, and the 

 other the Ottesen method, by A. Ottesen, Thistcd, Denmark. 



By the Dahl process, the fresh fish are packed in the shipping 

 boxes before being frozen. Cold brine, which has had its temj)era- 

 ture lowered, by contact witli crushed ice, to a point approaching 

 its freezing point is pumped through the boxes of fish, flowing back 

 through the ice for recooling. By this means the fish are frozen 

 quickly and the boxes may be headed and put in transit at once. 

 The plant consists of (1) a chamber for cracked ice, with compart- 

 ments so arranged that the brine passes through ice always in a 

 downward direction into a brine compartment; (2) a centrifugal 

 pump which receives the cold brine and discharges it through a de- 

 livery hose into the boxes of fish; (3) a freezing platform on which 

 the boxes rest, provided with troughs for conducting the brine back 

 to the ice chamoers for recooling. 



In the Ottesen plant the fish are placed in perforated, galvanized- 

 iron baskets, which are submerged in the brine, or, if the fish are of 

 large size, they may be suspended in the brine chamber until frozen. 

 In its simjdest form the equipment consists of an insulated iron 



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