QUALITY OF BUTTER

New Zealand Herald, Volume LXXIII, Issue 22398, 20 April 1936, Page 12

QUALITY OF BUTTER

Sir, —" Morrinsville Cocky " ditiagrees with my contention that the damage is done to the cream at tho production end, and yet agrees with " Progressive. Farmer " in saying ever/ shed should be made hygienic, ' then qualifies this by stating, "eliminate mud. and you eliminate most of the disease of stock, and also pave the way to make butter that will appeal to th» consumer at Home." I wonder if many farmers have considered just what action a.s regards contamination and propagation of bacteria does actually occur at each milking. In the first place, after milking, the usual practice is to sluice out the machine with cold and then bot ■water, and thereby conclude the machine is quite clean. But what actually happens is the water, both cold • and hot, is drawn through the teat ~ cups, and up the droppers, which have a diameter of only half an inch. It is quite impossible, therefore, to fill the milk pipe line, which has a diameter of between 1J- to 2in., so only about one-third of the interior of the milk line can possibly be cleansed. The other two-thirds is an ideal breeding ground for bacteria. The hot water is usually only at a temperature which aids propagation, so by next milking a high culture of . bacteria has taken place, when this culture is swept into the milk vat. The milk hag a temperature of approximately 93 degrees—perfect incubation heat. Milking operations have been in progress for between one hour and one and a-half hours before seperation is commenced, so that actually between two hours and three hours elapsed from the commencement of milking until completion of separation, giving two to three hours perfect incubation. The cream coming from the separator at a temperature of approximately 90 degrees is some 40 per cent solid fat, from which heat losses are very slow, making this bulk of ' cream another perfect incubation medium for r.apid rise in bacteria growth. Under perfect temperature conditions one bacteria will multiply within 24 hours to as many as 73,000,w0, so it can be easily understood the amount of propagation that goes on during the course of each * milking. 11 P.D.S." asks what process of dairy shed hygiene will effectively reduce the bacteria contamination. To effectively kill bacteria a temperature of 212 degrees Fahrenheit! is essential., As it is impracticable to immerse all dairy shed utensils in water of this temperature, the only effective manner of conveying such a temperature to machines, etc., is hv way of steam. This will fill the whole of the milk line and air line and pass through the whole of the plant. Only a few minutes of effective steaming is required to leave the machines in a perfectly sterile condition for next milking. All utensils such as buckets, vat and separator should also be thoroughly steamed; the, cream should be cooled as it comes frbm the separator, so as to prevent propagation of bacteria in the can. At a temperature of ;65 degrees and under it will more or Tless stay dormant. Only as the temi jTsrature rises does the bacteria progagation become really active. W. Perotal Lett.