CANNING SARDINES 155 
softening effect is particularly noticeable when the relative humidity 
of the air is high.” 
The question naturally arises as to how serious this sticking proved 
to be. Experiments were carried out with the new process through- 
out the 1923-24 season in San Pedro without special precautions being 
taken to prevent sticking other than to use relatively clean flakes. It 
was necessary, however, to place the fish on the flakes so that they did 
not touch each other. Under these conditions neither breakage nor 
marring from the flakes was particularly serious, except at the very 
end of the season, when very lean fish were cooked. There was some 
breakage (at times more than others), but on the whole it was little 
greater, if any, than that which occurred with fried fish. Even should 
breakage be more pronounced than with fried fish, this should detract 
but little from the selling quality of the final product. An occasional 
flake mark is less objectionable to most people than the presence of 
“old” frying oil. 
It was found that the sticking of lean fish to the flakes could be 
prevented by toughening the skins of the fish by drying in the same 
way as the skins are toughened for frying in oil. This was done by 
treating the fish with air that had a velocity of about 1,400 feet per 
minute and a temperature of about 140° for nearly 10 minutes. At 
the end of about six minutes the fish were shifted about on the flake 
so that the part in contact with the wires would have a chance to 
dry; otherwise, toughening the skins would have done little or no 
good. This treatment virtually eliminated sticking, both with 
medium “‘ovals”’ and quarter-oil fish. In fact, it was unnecessary 
to place these fish on the flake so as not to touch, as they tended 
to stick to each other but slightly. These experiments were carried 
out at the end of the sardine season in San Pedro, when fat fish or 
even those with a small amount of fat are seldom to be found. It 
was not possible, therefore, to try the effect of drying upon fat fish 
at that time. In experiments the following season at Monterey 
dried fat fish behaved about the same as untreated fish. It seems 
as though drying is really helpful only with very lean fish. Further 
experiments were not carried out. The experimental results reported 
upon here and their application are discussed in a later section. 
Drippings from the fish.—During cooking a small amount of juice 
and oil (if the fish are fat) drips from the underside of the fish, where 
they are in contact with the flake. Drying is not so efficient there, 
and gravity also tends to concentrate any free liquor at that place. 
Dripping was more pronounced with large fish than with small ones. 
This is natural, as large fish contain, in proportion to their size, as 
much water as small ones but less surface, per unit of weight, from 
which water can evaporate. 
It was more pronounced, too, when the fish were very fat and had 
been ‘“‘cut.’”” In any case, however, the amount of protein and oil 
lost in this way was small. The excellent drying conditions that 
prevail virtually all over the fish cause water to evaporate as soon as 
it reaches the surface and leave the dissolved substances behind. 
One naturally would expect the loss of oil from fat fish, cooked by the 
new process, to be large. It is not, however, because the action of 


® Although the following procedure is not recommended, being unnecessary, it would be possible to 
humidify the air used for cooling the fish in order to minimize sticking. There is one drawback, however— 
fish cooled in this way would be slightly sticky to handle, 
