CHEESEMAKING PROBLEMS

Taranaki Daily News, 11 September 1934, Page 33 (Supplement)

CHEESEMAKING PROBLEMS

DETAILS OF RESEARCH , THREE YEARS’ INVESTIGATION. CAUSES OF “OPENNESS” SOUGHT. At the time of foundation of the Institute the most pressing problem was considered to be the prevalence of “open” texture in cheese. It was perhaps natural to suppose that this fault was due to some particluar factor in the production of the milk or the manufacture of the cheese and that investigation would enable a finger to be laid on this point and the fault eliminated by suitable modification of technique. Unfortunately, the , problem has proved to be far more complicated. During the first three years practically every phase of the manufacturing process was investigated; and many popular theories as to the cause of openness were shown to be fallacious. The slits which occurred in cheese proved to be unconnected with any “fermentation” brought about by bacteria; pasteurisation of the milk was not responsible for the development of “openness” in the cheese; various methods of pressing the curd did not give any improvement. There were, however, some points about manufacture which influenced the incidence of the fault. Careless packing of the curd in the hoops increased openness. Too high a temperature of curing led to the development of more slits in cheese. Retention of cheese in the press for three days minimised the development of openness; and, most im-

portant of all, too high and too low a rate of acid development in the vat led in general to more open cheese. In a word, the problem was mainly a matter of keeping several variable factors “in tune,” as it were, during the manufacturing process, particularly acid development, expulsion of moisture from the curd, and temperature of cooking. These three main factors are mutually in-ter-related; and their . combined action controls the type of curd finally obtained. The occurrence or non-occurrence of openness is then often determined by the nature of, and the conditions for moisture retention in, the curd. When this became evident it was (-realised that insufficient was known about the chemical and bacteriological processes which take place in the transformation of milk into cheese curd. The work detailed in other paragraphs was therefore the outcome and the continuation of the preliminary work on “openness.” During the course of the earlier work on openness an attempt had been made to relate the occurrence of the fault to some peculiarity in the. chemical composition of the milk. Examination of the milk used in a number of factories and comparison of the results with the quality of cheese produced showed that there vzas no direct correlation between the simple chemical composition of the milk and the incidence of “openness.” With the progress of investigation it became increasingly evident that a more fundamental knowledge of the changes taking place in the cheesemaking process was required before much further progress could be made. Results so far obtained have already clarified the problem to a very considerable extent, more particularly with regard to the real meaning of whey “acidity,” and the cause of some previously little-understood anomalies in the changes in whey acidity. Work is also in progress which it is hoped will give a clearer understanding of the cause of retention of moisture by cheese curd and the means of removing the moisture from the curd.