FAULTS WITH CHEESE

Otago Daily Times, Issue 22356, 1 September 1934, Page 23

FAULTS WITH CHEESE

RECENT EXPERIMENTS QUESTION OF PAYMENT FOR MILK (Special to Daily Times) WELLINGTON, August 3L It has been quite evident that cheese faults such ae openness are bound up with the relationship between acid development in, and moisture expulsion from, the curd during the manufacturing process, states the tenth annual report of the New' Zealand Dairy Board. For any given milk there is an optimum sequence of events in the vat, which, if realised, will produce in general the closest cheese. Any departure, conscious or inadvertent, from this normal process is liable to lead to openness in the cheese. At present the optimum set of conditions for any milk can be found only by trial and error; and only -when more is known of the chemistry of the process will it be possible to give general laws. In this matter also the cheesemaker often is not in a position to follow the procedure he know's to be best, because the starter fails to act normally. Attempts to find out why starters vary from day to day, and efforts to gain a greater control over their activity, therefore form a large part of bacteriological research on cheese. Some , progress has been made towards the control of starters; and in an effort to put this knowledge into practice an apparatus was designed, suitable for use in factories, which would enable cheesemakers to keep mother cultures under what are the best conditions known at present. The use of this system has already eliminated _ trouble in some factories where great difficulty was experienced in keeping starters in an active condition. It is by no means a complete solution for all starter trouble, but it is an essential preliminary to the better treatment of starters in practice and gives the cheesemaker a better chance of achieving regularity in the working of his vats. PAYMENT FOR CHEESE MILK. There has been a persistent demand from cheese facctory directorates for information on the subject of payment of milk for cheesemaking. Since the information available w r as not considered sufficiently complete, the institute, for the last four months of the last dairy season, has made an extensive investigation of the subject. The preparation and study of the results are now well advanced, and the institute expects to be able to place ite report before the industry at an early date.

Work on discolouration in cheese has been continued. It has been quite definitely proved that bleached and pink discolouration is due to the presence of certain bacteria in the cheese-milk, since the trouble can be reproduced by the addition to milk of emulsions of discoloured cheese or of mixtures of bacteria isolated from discoloured cheese. Even bacteria isolated from apparently normal cheese of a certain age will reproduce the defect on occasion. It appears possible that any coloured cheese ultimately would show more or less discolouration round •slits in the cheese if kept loop; enough, and that, therefore, the difference between the conditions existing in normal cheese and those in discoloured cheese is one of degree rather than kind. The difficulty encountered in trying to define more exactly the cause of the trouble is that it has not yet been possible to determine the precise organism or organisms which produce the defect. The work is necessarily slow since some time must elapse in each experiment before it is possible to determine whether the experimental cheese will show discolouration.