MATURING OF CHEESE

Taranaki Daily News, 10 March 1932, Page 12

MATURING OF CHEESE

TESTS AT MASSEY COLLEGE INFLUENCE OF STORAGE PERIODS EFFECT OF AMOUNT OF RENNET. A somewhat technical but nevertheless very interesting address on the subject of experiments carried out recently at Massey College in reference to the factors affecting the maturing of cheese-was given by Professor W. Riddet yesterday to a meeting of about 60 men held in New Plymouth under the auspkes of the Taranaki branch of the Factory Managers’ Association. Summarising the results of the experiments, Professor Riddet said that given first-class conditions of milk and of manufacture it had been found that the best results were to be obtained by holding the cheeses for a month on the factory shelves at a temperature of 60 degrees Fahrenheit, subsequently keeping them in store at a temperature of between 48 and 50 degrees, and not selling them until they were 4} months old. The lecturer made it clear that his remarks applied to unwaxed cheese made from milk pasteurised at' 150 degress Fahrenheit. The resultant cheeses, he said, had a nice Cheddar flavour, and were the kind most acceptable on theEnglish market. The object of the experiments, said Professor Riddet, was to endeavour to overcome one of the difficulties mentioned by Mr. F. Nathan in a previous, address—the lack of correct maturity in much of the New Zealand cheese, whey it’ was opened up in England. Especially was this so with the spring make of cheese. Accordingly in February and March of last year 40 vats of cheese were made at Massey College, nine cheeses coming from each vat, which made a total of 360 cheeses. Each cheese was subjected to different conditions of manufacture and storage, amongst other factors taken into consideration being the amount of rennet used, for it was known that rennet could play an important part in the ripening of cheese. What was wanted was a mild, mature cheese, not too strong for the London trade. As a standard they used a cheese that was never subjected to a higher temperature than 50 degrees and was cut at an age of nine weeks; — the period taken in spring to hurry the cheese from the New Zealand factory to the English market. VARIOUS PERIODS OF HOLDING. Various periods of holding on the factory shelves were tried, as well as various, periods in store before opening up for sale, and various temperatures both in the factory and in store. A second series of experiments was made as though the object was to attain the highest yield possible, a third series was devoted to a cheese more salty and firmer in the body than the others, and in a fourth series an attempt was made to obtain a mellow bodied cheese slightly softer than the standard cheese but not so soft as the “high yield” cheese. Amongst the conclusions reached was that an increased amount of rennet tended to hasten maturity. An increased amount of rennet, however, in. the soft bodied cheese brought out by-flav-ours and decreased the value of the cheese for trade purposes. It was found that about four ounces of rennet per 10001 b. of milk was the best proportion, but the amount varied with the district. ■ ■ \ Professor Riddet went on to demonstrate, by means of a series of photographs and by explanations, how holding the cheese on the factory shelves too short a time and in store too short a time produced a rather bitter taste, and how even holding it in the factory for a month and in store for' only 31 montlrs still caused the cheese to be a little bitter. Cheese held on the shelves for six weeks was no better than that held for four weeks. In a similar manner the lecturer reviewed the effect on “openness” of . the various periods and temperature of storing. Soft bodied cheese, lie said, held at 50' deg. Fahr, all Along and cut after 13 weeks graded the best. Soft bodied cheese held on the factory shelves for a month or six weeks had a noticeable odour. This type of cheese deteriorated in quality very noticeably after its best stage had been reached, and from a trade point of view it was a most unsafe cheese to deal with. He did not have a good word to say for the soft bodied cheese in which yield was the main objective. extrX salt GIVES FIRMNESS. Cheese to which excessive salt was added was good bodied and firm, but at no stage did it really become the first grade cheese that was wanted on the English market. A large amount of salt caused the cheese to be very slow in ripening, and particularly in its early stages it had no true Cheddar flavour. The cheese in which mellowness was made the chief object was soft bodied, though not so much so as the “high yield” cheese, and did not stand up to the month on the factory shelves. The best results in this experiment were obtained from the cheese that stood on the shelves a fortnight at 60 deg. Fahr., and were cut at'an age of 16 weeks after being kept in store at a temperature of 50 deg. ‘ It was definitely established that the best cheese in the experiment was that held for a month on the shelves at 60 deg. Fahr, and cut at an age of 41 months. The soft bodied cheese intended for high yield and early maturity was the worst. The good quality cheese lost altogether about per, cent, of its weight before being opened' up, and the soft bodied, high yield cheese up to 6 per cent. In the soft bodied cheese there was in proportion to the other cheeses a .much greater weight lost in the period after leaving th” factory than in the period of the factory shelves. One important point obvious from the experiments, said Professor Riddet in conclusion, was that with good, clean milk and sound manufacturing methods it paid to mature the cheese. If the milk was not good and clean, and the make was poor, then maturing the cheese only made it grade worse and worse as time went on.

In reply to a question the lecturer said it was not known why some districts found it better to use more rennet than others. The amount varied as much as from 2oz. to soz. per 1000 lb. ■of milk. The matter was believed to be associated with the lime content of the soil, but this had not been definitely established.’ As a general principle he thought it best to use the smallest amount of rennet that would give the desired result/ Sometimes milk was not sufficiently ripened before the rennet w(as added. 1