DAIRY FACTORY PREMISES. 17 



the upper floor, are of wood. The walls and ceilings right throughout the 

 factory had been whitewashed with freshly-slaked hot lime a few days 

 previous to our inspection. This fact had a great bearing on the small 

 counts found in the atmospherically exposed plates, as the application of the 

 hot lime would have the effect of destroying many organisms especially 

 mould growths for the cultivation of 'which the medias used were specially 

 selected. 



The cream treated at the factory was in all cases delivered by road 

 vehicles in a few by carriers plying for hire, but mostly by the dairy- 

 farmers themselves. In transit from farm to factory it was held in 6 or 8 

 gallon cans, mostly of tinned steel and in good condition. The bulk of the 

 supply was received before midday. ~On arrival each can was weighed, 

 sampled for testing, and graded for quality. The cream receiving platform 

 was open to the yard, and there was no partition between it and the receiving 

 vats, pasteuriser, and pipe-cooler. After passing over the ground-floor 

 cooler the cream was pumped up to another cooler on the next floor, imme- 

 diately overhead, and from there taken in an open fluming to the holding 

 vats, which were fitted with coils in order to regulate the temperature and 

 bring it down as required for churning. This is necessary in the summer 

 time, as the cream remains in these vats overnight, being churned the 

 following morning. 



The upstairs cooler was placed in a small gable-end room with low ceiling, 

 through which was an air shaft ; further ventilation was provided through 

 a glass window, which was kept open, and through which a good breeze was 

 blowing at> the time the plates were exposed. The attemperator vats were 

 placed in an adjoining room of much larger size, but also with low ceiling 

 These vats were immediately over the churns. 



The cream examined was received in good condition and was closely 

 graded by the Department's officers, and found to be of choicest quality. It 

 will be seen from the plate Bl that much latent infection was present. The 

 great number of organisms of the coli group demonstrate contamination at 

 the cow-yard and bails ; other types present indicate that the cows had in 

 some cases access to swampy ground and pools of stagnant water. In B2 it 

 is shown that heating to 182 degrees Fah. practically sterilised the cream and 

 made it possible to manufacture from it a high-grade, good keeping butter, 

 thus proving that extreme care had been exercised in efficiently carrying 

 out pasteurisation. Untreated in this way, such cream would make a butter 

 that would deteriorate to a very low quality within a week. 



This care, with all the work and expense attached to it, was largely taken 

 in vain, because of the practice (already referred to) of adding unpasteurised 

 cream as a " starter " (see B3), the sharp acid flavour of which covered up 

 similar latent pollution to that previously destroyed in the bulk of the 

 cream by the pasteurising process. This infection was found in the butter 

 when marketed, and was mainly responsible for reducing its grade, when 

 made, froni 43 points for flavour (choicest quality) to 38 points (or second 

 grade and unfit for table use), some six weeks afterwards. In the interval 

 this butter was kept in cold storage at 10 degrees Fah. 



