FACTulJY OPERATIONS. 25 



IVa- are processed in retorts under pressure, or in a solution of 

 a calcium -alt. in order to secure a temperature above that of boiling 

 water. The germ- which arc found upon and associated with the pea 

 can not In- killed at hulling temperature unless it is continued for such 

 a length of time a.- to ruin the peas. The spores of these germs are 

 Mippo-ed to re-i-t any temperature below 240 F. for twenty minutes. 

 The time ami temperature nece.-.-ary to sterilize peas can not be given 

 with certainty becaii-e of the variation in factory practice and con- 

 dition- which mu-i be taken into account. If all factories handled 

 their material promptly after being cut in the field, allowed no ds- 

 lay-, Mich a- .-landing on wagon- up in piles to ferment, washed the 

 peas w'H M -""ii J- thra-hed. graded them equally well, blanched 

 them according '" their need-, -irnped and filled the cans the same, 

 tipped tin- can- at the -ame temperature, and brought them to the 

 pn.ce-> tank under like condition-, it would be possible to develop 

 a proce which might In- sale for nearly all localities. Such ideal 



lition- :nv not to be found in practice, and hence it is that one 

 factor] will employ a proce of _'!<> F. for twenty minutes and do 

 it successfully, while another mu-t double the time before being 



nahly MIC.-. I'M! in pi-eventing -poilage. 



The duration of the proc. -hould be considered as the length of 

 time during \\ h *D are Milunitted to a cooking temperature, 



and not the length of time they are in the retort. If a retort be filled 

 with en m-. it will take a few minutes for the steam or water 



to OOme I" a fairly -tationary temperature. When steam is used most 

 factories allow from llmv to live minutes to bring up the tempera- 

 ture, and v. hen water i- n-ed from right to ten minutes. This prac- 



i- often followed too do-elv. not taking into account the fact that 



B peafl are tilled and tipped while at a temperature of 180 F. and 

 ,,tl,,. r - : it inn \'. In the he-t of the hundred canning factories in- 



ird the mo-t careful attention was given to time and tempera- 

 ture of processing. The temperature wa- rai-ed gradually, continued 

 uniformly, and -hut oil -lowly. The circulation stopcocks were 

 opened and .-lo-d to in-ure a positive temperature at all points, and 

 the valve- adju-ted to meet any -light change above or below. 



For many year- the details of the process were considered a factory 



Bt, and' that feeling ha- not wholly passed away. It is evident 

 thai mod cannen allow a good margin of safety to prevent spoilage. 

 The majority follow the rules indicated by general practice and make 

 little attempt to vary them for particular conditions so as to get the 

 U-t |M> ible re-lilts. 



The proce- iriven to peas varies considerably in factory practice, 

 tin* h,we>t temperature being 230 F. for from twenty-five to thirty 

 minute.-. The rule, however, is to accept 240 F. as the proper 

 temperature and to vary the time from twenty-five to forty minutes. 

 There are a few who use the short period, but most packers consider 



