PRESERVATION OF FISHERY PRODUCTS FOR FOOD. 
477 
dowii when they blaze up too high. The smokehouse should always be warm aud 
dry before the lish are put iu, as the development of steam is apt to injure the tish. 
Even when using the same kind of wood, the length of time required to smoke an 
article of uniform grade depends largely on the condition of the weather, much 
longer time being required when the weather is sultry than when it is clear and windy. 
The length of time that smoked fish will keep depends on the extent of the salt- 
ing and smoking, and on temperature conditions. Hard herring will keep for a year 
or more; smoked halibut and haddock will keep only a few weeks, and those products 
smoked only a few hours are not likely to keep more than a week or so. If the 
Aveather be cold and dry, smoked fish keep very much longer than when it is sultry. 
Some curers, especially halibut smokers, prevent a liability to mold by sprinkling a 
small quantity of fine dry salt over the fish after smoking; others use compositions of 
boracic acid, salicylic acid, and other antiseptics sold under various trade names, but 
the best preventive is to keep the fish in a cool, dry place aud dispose of them as 
soon as lAracticable after smoking. 
Not content with the somewhat slow process of smoking, some dealers have intro- 
duced methods by which they reduce its extent, or else do away with it altogether, 
thus saving in time and in loss of weight of fish. Their process consists iu coating 
the fish with a form or composition of pyroligneous acid to impart a smoked flavor, 
and a coloring substance to give the fish the appearance of having been smoked. It 
is gratifying to know that these devices have not been favorably received in the 
United States. 
For the purpose of preparing a choice product especially for exportation to wmrm 
climates, the following process* of treating smoked fish has been introduced, but as yet 
its application in this country is of small extent : 
The hsh, after being sinoked, are cooled off and placed in layers in wooden barrels. Between 
each layer of tish a layer of dry salt is placed in a quantity of about 6 pounds of salt to 100 pounds 
of fish. The barrels, after having been filled, are kept in a cool place until the tish have become 
completely hard in consequence of the salt combining with the natural fat of the fish. This process 
of hardening must take jdace through the whole body of each tish, and can be ascertained by pressing 
the tish with the finger, which must leave no recess or impression whatever on the surface of the fish. 
After the process of hardening has taken place, which will be, according to the sort and size of fish, 
from within 3 to 15 days, the barrels are filled up with brine and then closed by a cover fitting tightly. 
The jirejiaration of the brine must be executed carefully in the following manner: Filtered water is 
boiled with salt to a saturated solution, which latter is allowed to cool off", after which it is skimmed 
and drawn off as far as it appears fully clear and pure. If the brine is not carefully jirepared, as 
above stated, the fish will not keep for so long a time, which will likewise not be the case if the 
process of hardening, before described, has not completely taken place. Fish prepared in the mode 
described will keep for many months and can be sent to hot climates without danger of spoiling. 
For making such preserved tish eatable it must be taken from the barrel and placed iu fresh water to 
remove its rigidness. This will, according to the size of fish, take place within from 3 to 8 hours, 
when the salt will be sufficiently removed from the fat. The fish is then dried in the open air aud 
will now fully resemble newly smoked fish. By first taking the fish in their natural condition and 
smoking them the juices are retained and the fat of the fish is brought to such condition that the salt 
when apx)lied will readily combine with it and make the fish perfectly hard aud solid, especially on 
the exterior. After the fish are thus smoked aud hardened with salt they are brought to a condition 
in which brine will simply preserve and protect them from atmospheric influences without changing 
their character in any material way. By thus treating the fish they are preserved without having 
the entire body of the fish permeated with salt, as after being smoked the dry salt in which they are 
packed combines chiefly with the fatty substances and forms a hard exterior surface which is not 
much i)enetrated by the brine. 
* See Letters Patent No. 352666, dated November 16, 1886. 
