In the first part of this study, brief notes are given on the better known varieties of the soft pickled group of cheese which the authors believe to be best suited to warm climatic conditions.

Domiati cheese, a variety of this group, characterized by the addition of an appreciable amount of salt to the milk prior to rennetting, is described in detail. An outline of the steps of its manufacture, the pickling process, and the effect of the amount of salt added to the milk on the composition of the resulting cheese is given.

In the second part the effects of varying additions of salt to both cows' and buffaloes' milk on rennet coagulation, rate of whey drainage, chemical composition and yield of cheese and whey were investigated.

An attempt was made to devise a medium for the growth of lactobacilli which would simulate the nutritive conditions existing in ripening cheddar cheese. The basal medium finally used contained soluble digestion products of casein (formed by the action of rennet), lactose, lactate and phosphate. This medium gave a fair, but not a very heavy growth of flavour-producing lactobacilli isolated from cheddar cheese, and it was evidently deficient in growth-promoting power as compared with some media used in the laboratory. Additions of potassium and manganese salts to the casein digest medium gave a significant increase in growth. Potassium had the effect of off-setting the inhibition caused by the presence of an excess of sodium salts such as are normally present in cheese. The implications of the results in cheese ripening and their possible application in cheese manufacture are discussed.

In grading Cheshire cheese, assessments are made of the ‘body’, ‘texture’, ‘crumbliness’, flavour and overall quality. In commercial grading in this country (England) it is not usual to apply a scoring system to these various characteristics, although, in judging cheese for show purposes, points would be assigned to each item. American practice, at least according to the literature, suggests that score cards are in general use for each particular dairy product, so that the various items may be assessed in quantitative terms. For experimental purposes, where it is required to assess the effect of specific variations in conditions of manufacture or storing of the cheese, or to assess the relation between instrumental tests and the judgements of graders and others, some quantitative form of expression of these judgements is essential. However, it has to be borne in mind that the process of forcing the judgement into an arbitrarily selected numerical scale may lead to a certain amount of distortion and may not be entirely satisfactory. Modifications of procedure desirable in the interests of statistical planning may also be unacceptable, in view of the dislocation they may cause to the ingrained habits of the professional foodgrader.

In a paper by Mattick & Shattock (1) it is stated that: ‘The suspicion exists in the minds of those who investigated cases of gastro-enteritis that streptococci of the faecal type isolated from suspected cheese may have been responsible for the disease.’ They examined thirty cheeses and found that the faecal types of streptococci were common, and that the haemolytic varieties were rare. Since then the question has arisen as to the identity of the haemolytic streptococci found in cheese examined for the presence of the pathogenic streptococci. While we have never had occasion to examine cheese suspected of harbouring pathogenic organisms, the presence of haemolytic varieties of streptococci, their identity, and their role in cheese œcology is of general interest.

During the autumn of 1946, samples of two Cheddar cheese, one of Canadian, the other of New Zealand manufacture, which had been held in a frozen state (in cold store) for about 7 years were presented to this Institute.

Some years ago discoloration was reported in mature New Zealand export cheeses. The defect occurred typically as bleached or pink areas surrounding cracks, though a less frequent ‘muddy’ discoloration was also noted. Discoloration was, on the whole, restricted to cheeses made in warm weather. Preliminary observations showed that the defect had certain characteristic features, viz.