CHEESE FACTORY MANAGERS

Southland Times, Issue 22993, 12 September 1936, Page 9

CHEESE FACTORY MANAGERS

ADDRESS BY DR. W. R. WHITEHEAD A DISCUSSION ON STARTERS

At a fully representative meeting of the cheese factory managers of Southland and Otago, held in the Trades Hall yesterday, Dr W. R. Whitehead, of Massey College, gave an interesting lecture on research work with cheese starters. Mr W. Bagrie (Seaward Downs) was in the chair. Dr Whitehead said that for a long time nothing had been known about starters. Eventually they were able to pick out the germs most active, and these could be used as pure cultures for cheese-making. Even with these sudden failures had occurred. They then found that most of these failures could be explained by the developments in the cultures of a virus called bacteriophage, which dissolved the germs and destroyed them. At first it seemed a possibility that this virus was a contaminant, but it was now believed that it was formed by the germs themselves. In order to cure the trouble it was necessary to find the particular conditions in the milk which induced the phage to develop. Failures With Starters. The speaker went on to say that there were two keys to the problem. Firstly, certain cultures were all right if the milk were pasteurized and cooled and kept still, but when the milk was moved about there was trouble with the starters. Secondly, failures with starters were more frequent in cans than in tubes—in fact, there were rarely failures in tubes. Cultures had periods in which they were sensitive and insensitive. The composition of the milk, and the type of factory it was manufactured in, were not of great importance. Dr Whitehead urged them not to try only the milk of the three best suppliers, but to use the milk of any supplier. They then might find that the difference in the milk was at the bottom of the trouble, although this was problematical. There were many safeguarding methods that had been adopted. The adoption of the .mother cultures had improved the position. If a can of milk were inoculated with three different cultures this sometimes improved the position, but not always, as sometimes all three starters would fail. Some managers made up the starter the day before, then made a vitality test and, if it were successful, used it in the vats. It was also found that starters might remain more active in tubes if used in factories. However, unless they survived more than one generation’in that tube they were of little value. He went on to urge them to take the vitality test, which was used more in the North Island than in the South, as it would give them some guidance as to which to use and which was the more active. Some difference in the milk composition was at the bottom, of the whole trouble. It was a question of which, of any given starter, was the most reliable for the most times. Need of Co-operation. Mr A. Gulliver, dairy instructor in Southland, said that the starter question was a complex one and that good results would only be obtained by cooperation. At one time it was thought that the trouble was due to contamination or over-ripening, or both, but sterilizers and other preventives had been introduced, and the trouble still persisted. The remedy was still a missing link. No matter whether the managers were careful or careless, they, all experienced similar trouble. Investigation work had covered a wide . area, both bacteriologically and chemically, but he was of the opinion that more attention could be paid to the chemical side. It was a fact that some factories produced a better type of cheese than others, irrespective of the factory and the manager. For the first six weeks of this year no trouble had occurred at all, then without any warning there had come a collapse. Mr Bagrie asked the speaker, if he had ever placed any relationship between the starter failure and the mother culture in the tube. Could the failure of the starter be attributed to the different type of container? The reply was that everything had been tested under factory conditions and there had been no difference noticed at all. In reply to a question bv Mr W. McEwan (Mataura Island), Dr Whitehead said that in the South they pasteurized twice as long as was necessary. The time of pasteurization made no difference and was no solution to the problem. The body of the starter counted for nothing. Nor did the flavour of the starter indicate the flavour of the cheese. Weather Not a Factor. In answer to a question by Mr Bagrie, Dr Whitehead said that as far as he could see there was no connection between the trouble and dry weather, wet weather and the seasons. Since the introduction of milk grading some factories had done worse and some had done better. Mr G. Dixon (Edendale) said that the whole problem was the starter. Answering a question by Mr A. Harper (Woodlands) Dr Whitehead said that the high or low productivity of the cow did not affect the cheese. As a matter of fact the trouble was less acute here than in the North Island, where it was particularly bad in the Waikato and Bush districts. Mr A. Linklater (Drummond) raised the question of starving the starters, Dr Whitehead replied that it did not matter when making up a mother starter whether they used one drop or ten drops. After some discussion Dr Whitehead gave it as his opinion that starters went better when kept low.