CANNING SARDINES 101 
fried. Then, if the only consideration is to keep the fish-oil content 
at its lowest, the oil should be allowed to increase as much as con- 
ditions permit and as long as such a condition exists. Although it 
has been shown that usually it is best to keep the fish-oil content of 
frying oil as low as possible, in this special case undoubtedly it would 
be better to remove the excess oil as it collects and fry in the mini- 
mum amount of oil because of the distinct advantages that come 
from rapid oil replacements. 
The second run of frying experiments furnishes an example of the 
beneficial results to be obtained from an application of the principles 
discussed here. In the second run almost twice the quantity of fish 
was fried per gallon of oil used as in the first, yet final oil con- 
ditions were comparable. In the second run there were approxi- 
mately twice the oil replacements there were in the first run and less 
time for the simultaneous action of high temperature and air. It 
can hardly be argued that different oils were used in the second run, 
because fish oil is soon the main oil in any case where fat sardines 
are fried. 
Improving the quality of “old”’ oil.—It would be a distinct advantage 
were it possible to prevent objectionable properties from developing 
in frying oil by frequently treating the oil or by removing objection- 
able substances as they are formed. Experiments along these lines 
were unsuccessful. Apparently little is to be expected from such 
attempts when one realizes that there is only one sure method of 
removing the taste and odor from fish oil—namely, hydrogenation— 
and this is impracticable with a contaminated, oxidized oil. 
It is advisable, however, to handle this oil properly during use. 
When frying is completed, the oil should be separated from the 
“foots” and water and stored in a clean tank, preferably away from 
the air. The ‘‘foots” should be heated gently to “break” the emul- 
sion and the clear oil obtained added to the other oil. More oil can 
be obtained from the remaining “foots”’ by boiling the water out of 
them. This oil should not be used for frying, as it is likely to be of 
poor quality. The frying vat should be cleaned, of course, and fresh 
water added when it is used again. Some canners claim that it pays 
to centrifuge the frying oil. Undoubtedly this is helpful, as it 
removes water and finely divided particles from the oil. 
Using better-suited and cheaper oils —There are oils and fats more 
suitable in many ways for frying purposes than cottonseed oil. Since 
oxidation changes are the main ones that take place in oil used for fry- 
ing sardines, it would appear better to use an oil that is especially 
resistant to oxidation. In the experiments such an oil was used— 
namely, Crisco, a hydrogenated oil. No better results were obtained 
from its use, however. It is easy to explain this behavior. When 
fat fish are fried, it is not long before the oil first placed in the fry 
bath has been replaced by fish oil. The Crisco did not remain in 
the vat long enough for its desirable properties to show up. Under 
such conditions it makes little difference what kind of oil is used for 
frying, providing it stands up reasonably well under use and has no 
objectionable flavor or odor. When lean fish are cooked, however, 
it would be well to use an oil that is resistant to oxidation, since this 
is the main oil always in the cooking vat, losses being made up by 
adding new oil. 
