474 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
PRESERVATION OF FISHERY PRODUCTS BY SMOKING. 
Fish and other food products have been preserved by smoking from time immemorial. 
The process was well known in Europe during the fourteenth century, and it appears 
to be used by savage tribes of many different localities. It consists in exj)osing the 
articles fresh or, as is more frequently the case, slightly salted, to the action of smoke 
produced by smoldering wood, bark, or sawdust. Its efficiency depends upon the 
drying as well as the action upon the texture of the fish of the pyroligneous acid pro- 
duced by the smoldering, which at the same time imparts an agreeable flavor to the 
liroduct. Smoking is practiced to some extent by nearly all nations, especially in 
curing oily species of fish, such as herring, haddock, halibut, salmon, etc. ■ 
In the United States smoked fish are cured either round, eviscerated, split and 
beheaded, or cut into small pieces with or without the skin removed, according to the 
species. Small sea herring, cured as hard herring, and biickliug, alewives, fresh 
mackerel, etc., are usually not dressed at all; bloater herring, lake herring, eels, salt 
mackerel, flounders, etc., are usually split down the belly to the vent and eviscerated; 
salmon and haddock are usually split so as to lay out flat like dried codfish, and 
halibut, sturgeon, and sometimes catfish, are cut up into small pieces before smoking. 
After being dressed the fish are at once struck with salt, the length of the salting 
differing according to the species being prepared, but ranging from an hour or two 
to a week or more, and in case of halibut, salmon, mackerel, etc., they may be smoked 
after being salted a year or two, the excess of salt being removed by soaking in water. 
On removal from the pickle the fish are cleansed and attached to smoking-sticks and 
after drying for a few hours are placed in the smokehouse, or, in case of halibut, they 
may be dried on cod flakes for a day or so and then strung on sticks and placed in the 
smokehouse. All fish cure better and present a neater appearance when cured, if 
dried in the open air a few hours before being placed in the smokehouse. 
Both cold-smoking and hot-smoking are employed, the result of these two proc- 
esses being quite different. In the former, the fish are suspended at a distance from 
the fire and smoked at a temperature less than 80° F. ; in the latter process the fish 
are partly or entirely cooked while smoking, being hung near the fire. In cold-smoking 
the exposure may be only a few hours, as in the case of salmon, or it may continue 
for weeks, as in curing hard herring, the length of exiiosure depending on the article 
jwepared and the time that will probably elapse before it is consumed, whereas 
hot-smoking is always completed within a few hours, usually within three or four. 
Cold-smoking is used principally in the United States, England, Norway, Holland, 
Russia, and Scotland. It is applied to herring, alewives, halibut, haddock, salmon, 
salt mackerel, flounders, butter-fish, etc. In Germany and Sweden hot-smoking is the 
more imiiortant, but it is not extensively emiiloyed in the United States, being confined 
mainly to New York, Chicago, Milwaukee, and other centers of foreign population, 
the species so treated being sturgeon, lake herring, whitefish, eels, catfish, fresh 
mackerel, etc. 
