Ko. 4(^921) BRIXE-FREEZING 43 



completely freeze until their temperature is reduced to — 9"4^ C. 

 (T5°F.). 



Appcarajicc. — Air-frozen fish have often certain outward charac- 

 teristics that condemn them in the judgment of the corisumer. 

 Consequently frozen fish -by which is meant air-frozen fish — fetch 

 low prices compared with fresh fish in spite of all efforts to break 

 down what the cold-storage firms declare is an unfounded prejudice ; 

 in the words of the fish salesmen " the British public will not buy 

 frozen fish at any price if fresh fish be obtainable." The prejudice 

 is, in fact, well grounded in the vast majority of cases. Impartial 

 examination of average air-frozen fish shows unmistakable out- 

 ward signs of deterioration in the sunken, cavernous eyes, and a 

 slight but distinct shrivelling and wrinkling of the skin. On 

 thawing, the fish, unless it possesses an exceptionally firm flesh such 

 as the salmon has, assumes a flabby appearance wholly repellent 

 and the wrinkling of the skin appears actually to increase. This 

 soft flabbinesS' characterizes defrosted fish irrespective of the 

 length of sojourn in the cold store; it is due to the rupture of the 

 tissues in the manner mentioned below, whereas shrinking of eyes 

 and skin is caused by the abstraction of water by evaporation 

 during a prolonged period of exposure to cold dry air— in the case 

 of air-freezing thirty to thirty-six hours with fish of 5 to 6 lb. in 

 weight, and longer still when larger fish have to be dealt with. 



When fish are frozen in brine, no loss of water by evaporation 

 is possible; at the end of the process, the fish are absolutely of the 

 same appearance as when they were put in, or rather they appear 

 to have improved, being rigid and bright. The diff'erence in the 

 appearance of the eyes in fish frozen in brine and air respectively 

 is perhaps the most marked feature; in the one, rounded and 

 natural, in the other deeply sunken and dull; when thawed out, 

 the dift'erence in favour of the brine-frozen is intensified. 



Loss of weight. — That an appreciably greater loss in weight 

 takes place during air-freezing, is obvious from what has been 

 said in the preceding paragraph upon the evaporation that takes 

 place during the prolonged period necessitated by air-freezing. 



Keeping qualities, and retention of fiavour. — As already remarked 

 air-frozen fish when thawed out, with certain exceptions due to 

 specially hard and dense flesh, are flabby and soft, and in practice 

 are found to go bad more quickly than either fresh fish or brine- 

 frozen fish. Bjth the latter hive almost identical keeping 



