110 MADRAS FISHERIES BULLETIN VOL. Xllt, 



158. The operations of testing, exhausting, and processing, 

 have been fully described above (paragraphs lOI — ]29). But 

 sardines in oil need not ordinarily be exhausted 



(i) if thoroughly full of oil ; 



(2) if the cans are so dished that air is practically excluded. 

 The omission of exhausting greatly saves time and labour which 

 balances the cost of any excess of oil so used. But ' plain ' 

 sardines packed without oil must be exhausted, since there is 

 considerable air in such cans. 



159. The time of processing varies according to the size of cans 

 and the method ; in open boiling pans at 212° F. quarters usually 

 get not less than I ^ hours; in steam pressure kettles the time is 

 about 30 to 35 minutes. Halves (weight about I lb.) get about 2 

 hours and 45 minutes respectively. 



160. It is possible to can sardines in oil in very large tins, e.g., 

 gallon or 4-gallon kerosine tins in such a way that when opened 

 they will keep good for some days so that a retailer can sell sar- 

 dines in oil to his customers by the pound or less. At Beypore the 

 sardines were brined for a considerably longer time than usual, 

 viz., for an hour or two (taking care that brine is kept at saturation 

 point), and were then treated as usual right through to processing, 

 which of course must be long in proportion to the size of the cans. 

 These cans were afterwards opened and left exposed to the air ; 

 none went bad though open for many days, but in the warm damp 

 climate mould appeared on the surface. Special care must be 

 taken with the larger tins ; the plate must be extra stout, and, if 

 kerosine tins, the seams must be, or be made, perfectly air tight by 

 floating with solder. The tins should be packed closely and filled 

 with the oil so as to exclude air as much as possible ; otherwise 

 when exhausted, as is necessary, and then processed, the tins will 

 appear as though battered and may collapse. For if there is 

 much air before exhausting, the operation of exhausting will drive 

 out the air leaving only steam ; when, after processing, the steam 

 condenses, the internal vacuum will be considerable, and the tin 

 will fall in at many places. Cylindrical cans of 8 lb. and upwards 

 may usefully be packed in this way, and if lock-seamed and solder- 

 floated will, if properly treated in packing and exhausting, retain 

 a good appearance. 



161. Plain sardines. — These are greatly esteemed by those who 

 wish for the natural flavour of the fish. This method should only 



