2 BULLETIN 740, U. S. DEPARTMENT. OF AGRICULTURE. 



COMMERCIAL TREATMENT OF OYSTERS. 



As a slight knowledge of the methods of handling oysters is neces- 

 sary for a clear understanding of the various subjects touched upon 

 in this bulletin, a brief outline of the essential features involved in 

 the preparation of oysters for the market, beginning with the dredging 

 of the mature oysters, that is, those which are three or four years of 

 age, will be given first. 



Oysters are grown in water of a salinity ranging from 1.5 to 3.5 

 per cent, calculated as sodium chlorid, the average being about 2.5 

 per cent, and are covered to a depth of from 5 to 50 feet at mean low 

 tide. In many cases the beds are so far from the oysterhouse that 

 upon arrival the oysters may have been out of water for several days. 

 For the beds near the house the period is shortened to a few hours. 

 "Shucking" oysters, the process of opening the shells and removing 

 the meats therefrom, is always done by hand, and those engaged in 

 the work are called "shuckers." The shucker puts the oyster meats 

 into a perforated dipper holding 1 gallon. From the shuckers' dippers 

 the oysters are emptied upon the "riffles," inclined, corrugated metal 

 boards, down which a thin stream of water runs. The slight bumping 

 caused by the corrugations tends to remove the bits of shell which 

 may cling to the body of the oyster, and the water both hastens its 

 progress and washes off most of the dirt which it has acquired during 

 the process of opening. From the riffles the oysters slide through 

 metal chutes to the sorting table, where they are graded and those 

 not fit for food are culled out. In Connecticut the following grades 

 of oysters are recognized: (1) " Straights," the name given to the 

 entire output of the plant, not graded, with only those unfit for food 

 removed; (2) " counts," very large oysters, not mutilated in opening, 

 perfect in shape and color; (3) "selects," smaller than "counts," but 

 larger than the ordinary run of stock, unmutilated and perfect in 

 shape and color; (4) "standards," the ordinary run of stock from 

 which the "counts," "selects," and "culls" have been removed. 



From the sorting table the oysters slide down metal chutes to the 

 washing and chilling tanks, where they are thoroughly washed in 

 running water, and chilled by means of ice, if the weather is warm 

 enough to require it. The method of washing and chilling oysters 

 had changed materially in the years immediately preceding the time 

 of this investigation, and, instead of only one method, several methods 

 were in use. The old method of preparing shucked oysters for the 

 market consisted in washing the stock as received from the shucker 

 upon a perforated "skimmer board," by means of running water 

 from a hose, the oysters being moved about with a paddle during 

 the process. The oysters were then placed in tanks of ice water with 

 chunks of ice, and chilled for a period of time not exceeding 20 

 or 30 minutes. Mechanical devices, however, had been invented 



