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BC/AfviCA.L 

 BULLETIN 130. ^^^i^EN DECEMBER, 1903- 



Ontario Agricultural College and Experimental Farm. 



A COMPARISON OF THE BACTERIAL CONTENT OF CHEESE 

 CURED AT DIFFERENT TEMPERATURES. 



By Pro'f. F. C. Harrison and Prof. W. T. Connell. 



The {oUowing investigations were made partly at the Agricultural Col- 

 lege, Guelph, and partly at the Eastern Dairy School, Kingston, the latter 

 being done under the direction of the Commissioner of Agriculture and Dairy- 

 ing for the Dominion. The object was to determine the bacteriological con- 

 ditions existing in Canadian Cheddar cheese when cured at dififerent tempera- 

 tures; to note the relationship existing between the bacterial contents and 

 other curing agencies; and to learn, if possible, some lessons of practical value 

 for those engaged in the production of cheese. 



Sources of Cheese Analy.sed. 



The cheese subjected to analysis were of two distinct groups. The tirst 

 group consisted of those made and kept at the factory at Carp, Ontario, dur- 

 ing the seasons of 1899 and 1900. This lot coimprised 28 cheese in all, 14 being 

 analysed in 1899 and 14 in 1900, each cheese being examined a number of 

 times at various intervals. One-half the cheese examined each season was 

 kept in an insulated curing room at a temperature varying between 60 and 65 

 degrees Fah., the average for both summers being 62.2 degrees Fah., the maxi- 

 mum recorded being 67 degrees and the minimum 56 degrees. The remain- 

 ing half was kept in an ordinary curing room in which no attempt was 

 made to control the temperature. The average temperature of this room in 

 1899, vvhile containing the cheese analyzed, was as follows: Last fifteen days 

 of June, 68.7 degrees Fah.; July, 70.5 degrees Fah.; August, 70.8 degrees Fah. 

 The average temperature of this room in 1900 was: July, 72 degrees Fah.; 

 August, 69 degrees Fah. 



The temperature of the insulated room, which was isolated from the ordi- 

 nary curing room, was regulated by a sub-earth duct and by'the use of ice in 

 racks. Full details as to methods of structure and insulation of the ordinary 

 curmg room and factory are given in the reports of the Commissioner of Agri- 

 culture and Dairying for 1899. 



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i Bull 130 



