DAIRY FACTORY PREMISES. 27 



Sampled Cream before Pasteurising. The cream, as received in cans 

 from the various suppliers of the factory, after being weighed and sampled 

 for testing, was graded, and the best quality pumped into a 600-gallon 

 pasteurising holder of the batch type. The acidity of the bulk cream, after 

 this had been well mixed by the rotating coils of the pasteuriser, was 

 determined at 0-48 per cent, lactic acid. A neutralising agent (lime) was 

 added in order to reduce this acidity to the requisite percentage before 

 pasteurisation was carried out. The sample for plating was collected from 

 the bulk cream by means of a sterile pipette in the holding vat, after 

 blending was completed and before the lime had been added. From the 

 plates it was evident 1 c.c. of the cream contained 150,997,000 micro- 

 organisms; of these, 150,000,000 were Bact. lactis acidi, or desirable lactic 

 fermeiiters, and 200,000 were streptococci. Of the total count, 498,000 

 bacteria (including organisms such as Proteus vulgaris, B. subtilis, Bact. 

 fluorescent liquefaciens, Bact. fulvum, and a micrococcus) were able to 

 liquefy gelatin or digest casein of milk ; 248,000 were organisms of the 

 coliform group, or undesirable lactose fermenters, while of the 45,000 

 bacteria which cause alkalinity in litmus milk, Bact. alcaligenes was most 

 numerous. Others, both spherical and rod forms, were considered inert, 

 causing no apparent change in litmus milk or gelatin in ten days. 



Sample (72 Cream immediately after Pasteurising. The cream had been 

 neutralised to 0'25 per cent, acidity with lime and pasteurised by means of 

 the holding system, where the cream was raised to 145 deg. Fah.,and held at 

 that temperature for twenty minutes. The sample for plating was collected 

 by means of a sterile pipette direct from the vat before the cooling process 

 began. From the plates, 1 c.c. of the cream contained 500 bacteria ; of 

 these 490 were gram positive bacteria, which slowly coagulated litmus milk 

 with production of acid, and ten of a sporing bacillus of the B. subtilis type. 



Sample (73 Cream immediately prior to Churning. The pasteurised 

 cream was cooled to 55 deg, Fah., and allowed to remain in the pasteurising 

 vat twenty hours (overnight). The lid of the vat was kept closed, and no 

 " starter " was added. The sample for plating was collected by means of a 

 sterile pipette direct from the bulk in the vat. From the plates, 1 c.c. of 

 cream contained 13,400 bacteria. Of these, 1,900 were Bact. lactis acidi, or 

 desirable lactose fermenters, 3,800 were streptococci, and 7,500 (including 

 spore-forming organisms of the B. subtilis type, Sarcince and Cladothrix sp.) 

 were able to liquefy gelatin. One hundred and fifty were bacteria able to 

 produce alkalinity in milk, and fifty were chromogenic micrococci, classified 

 as inert, having caused no apparent change in litmus milk or gelatin in ten 

 days. 



Sample (74 Butter in the Box after Packing. The cream from the pas- 

 teurising and holding vat was gravitated along a fluming into the churn in 

 another room in the factory. The cream was churned in the. Simplex churn. 

 The sample for plating was collected by means of a sterile instrument from 

 the near surface butter as packed in the box ready for market. From the 

 plates 1 gram of butter contained 750,000 micro-organisms. Of these, 90,000 



