and prevent the growth of the undesirable ferments. In this day of hand separators, where the cream that needs to be kept under control is but a small fraction of the milk from which it was taken, the desired conditions of temperature are easily obtained. If the temperature during the entire process of manufacture, from the time the cream is cooled after separation to the time the butter is packed ready for market, is not allowed to exceed 60° F., one important condition will have been met, tending to improvement of dairy butter. (4) Ripening the cream. The quality of butter depends upon the proper ripening of the cream more than upon any other single step in the process of making. It is safe to say, too, that a person who is particular and successful in ripening cream will not be likely to lack in other requirements of a prime butter maker. All successful makers are now depending almost entirely upon a "starter" of some kind to ripen their cream. The present status of butter making would seem. to indicate that the "starter" is almost necessary to make uniformly good butter. There are two classes of starters-the commercial and homemade—and either will give excellent results if properly handled. One or the other should be used by every butter maker who aims to produce a high-grade article. In connection with the "starter" in ripening cream may be mentioned the use of the acid measure to determine the amount of acid that has been developed. Experience has demonstrated that an insufficient amount of acid in the cream will fall short of giving satisfactory results, while too much will be detrimental. In order to know when the desired point in acidity is reached (and this is generally agreed upon as 0.55 to 0.65 of 1 per cent of acid), it is necessary to have some kind of an acid measure. The most convenient form of measure for home use is no doubt the Farrington alkali tablets, which may be obtained from almost any dairy supply house, with full directions for use. THE COLD CURING OF CHEESE.a By HENRY E. ALVORD, C. E., Chief of Dairy Division, Bureau of Animal Industry. INTRODUCTION. The prevalent opinion among cheese dealers has always been that low temperatures, varying from 35 or 40 to 50 F., or thereabouts, resulted in the production of an inferior quality of cheese, in comparison with that from 60 to 70° F. No carefully controlled experiments bearing on this problem have been recorded earlier than those undertaken by Babcock and Russell at the Wisconsin Agricultural Experiment Station, and described in the Fourteenth (1897) Annual Report of that station. The results of those tests showed that cheese placed at refrigerator temperatures (45° to 50° F.),' directly from the press, was of superior quality as to flavor and also as to texture, and that such cheese was wholly free from any bitter or other undesirable taints. In connection with their studies on the influence which galactase and rennet extract exert on the progress of cheese ripening, the same investigators later employed still lower temperatures (25° to 30° F.). Cheeses were kept at these excessively low-curing temperatures for a period of eighteen months. The quality of these cheeses, cured as they were below the freezing point throughout their whole history, was exceptionally fine, and emphasized still more than the previous experiments did the fact that the ripening of cheese can go on at much lower temperatures than has heretofore been considered possible. These results led to an extended series of experiments, in which cheese made on a commercial scale was cured at a range of temperature from below freezing (15 F.) to 60-a point which common practice has now accepted as the best obtainable temperature that can be secured without the use of artificial refrigeration. In these experiments (consisting of five series made at intervals throughout a period of two years) 138 cheeses were used, for which 30,000 pounds of milk were required. These experiments were upon a @ Appeared also in much more extended form in Bulletin 49, Bureau of Animal Industry. The first public presentation of these experiments was made at the meeting of the Wisconsin Cheesemakers' Association, in February, 1901. a scale which represented commercial conditions, and therefore obviated the objection which is often urged in commercial practice against the application of results derived simply from laboratory experiments. The results of these tests may be found detailed in Bulletin No. 94 and the Eighteenth (1901) and the Nineteenth (1902) Annual Reports of the Wisconsin Agricultural Experiment Station. The Ontario Agricultural College began experiments on the cold curing of cheese in April, 1901. As a result of these tests, the conclusion was drawn that the cheese cured at low temperatures (averaging 37.8° F.) was much superior to that cured in ordinary curing rooms (average temperature during season 63.8 F.). Mr. R. M. Ballantyne, a prominent cheese expert, said of this cheese that "they [the merchants] universally expressed surprise at the condition of the cheese that was put into cold storage at the earliest period (that is, directly from the press), as they expected to find the cheese still curdy and probably with a bitter flavor." If this experiment is borne out by other experts, it would appear as if the best way to handle hotweather cheese would be to ship it to the cold storage directly after making, and this would certainly mean a great revolution to the trade.a A considerable number of experiments have also been made at other stations (Dominion government tests and New York State and Iowa experiment stations), where somewhat lower temperatures were used than those which are normally employed for ripening. The results obtained all show an improvement in quality that becomes more marked as the temperature is reduced. In order that a much larger experiment might be instituted, covering the different types of cheese as represented by Eastern as well as Western manufacture, Drs. Babcock and Russell, of the Wisconsin Station, presented this matter for consideration to the Dairy Division of the Bureau of Animal Industry. As a result of this proposal the officers of the New York Agricultural Experiment Station were also consulted and plans perfected for the cooperative experiments conducted simultaneously in Wisconsin and New York, which are described in full in Bulletin No. 49 of this Bureau and special bulletins published by the two State stations. It should be noted that it was so late in the season of 1902 when the arrangements for this work were completed that it was impossible to obtain favorable conditions in all respects. It was deemed desirable that the cheese to be tested should represent the product of as wide a range of territory as possible, and therefore it was decided to establish two curing stations-one in the East and the other in the West. Drs. S. M. Babcock and H. L. Russell were put in charge of the Western experiments and Dr. L. L. Van Slyke and Mr. G. A. Smith of those in the East. a Bulletin No. 121, Ontario Agricultural College, June, 1902. OBJECTS OF THE EXPERIMENTS. In addition to the influence which a range in temperature exerts on the quality of cheese, as determined by flavor and texture scores, instructions were also issued to secure data regarding the loss in weight which the different lots of cheese suffered at the different temperatures. The commercial quality of the product was to be determined by a jury of experts who were thoroughly in touch with the demands of the market. Although the effect of coating cheese with paraffin soon after being taken from the hoop was not at first proposed as a part of this work, it was finally included, both East and West. The temperatures selected for these experiments were 40°, 50, and 60° F. It may be assumed that the advantages of a cool and even temperature in curing Cheddar cheese have been already established in preference to a warm temperature or to very variable conditions which frequently include periods above 702 and sometimes much higher. As already stated, 60° or thereabouts is regarded as the lowest temperature practicable without artificial refrigeration; this may therefore be taken as fairly representative of what may be called a “cool” temperature for curing cheese. And rooms held at 40° and 50 were selected as representative of a "cold" temperature for curing, or compara. tively so. It is thus hoped to emphasize by these experiments the distinction between cool curing and cold curing. The cheese for these experiments was purchased by the United States Department of Agriculture, which also paid all expenses of transportation and storage and for the experts who made the periodical examinations. The two experiment stations selected the cheese, arranged all details of storage and examination, supervised the work throughout, performed the chemical and other incidental scientific work, kept the records, and reported results. ADVANTAGES OF CURING CHEESE AT LOW TEMPERATURES BRIEFLY SUMMARIZED. (1) The loss of moisture is less at low temperatures, and therefore there is more cheese to sell. (2) The commercial quality of cheese cured at low temperatures is better, and this results in giving the cheese a higher market value. (3) Cheese can be held a long time at low temperatures without impairment of quality. (4) By utilizing the combination of paraffining cheese and curing it at low temperatures the greatest economy can be effected. (5) The production of a thoroughly broken-down Cheddar cheese of mild, delicate flavor and perfect texture meets a demand which it is impossible to satisfy with cheese cured at high temperatures. Without any question, if the general market can be supplied with this mild, well-ripened cheese, consumption will be greatly stimulated, not only by increasing the amount used by present consumers, but by largely extending the use of this valuable and nutritious article of food. EXPERIMENTS OF 1902-03. The Western experiments were conducted by S. M. Babcock and H. L. Russell, assisted by U. S. Baer, of the Wisconsin Experiment Station. Suitable arrangements were made at the cold-storage warehouse of the Roach & Seber Company, Waterloo, Wis., where rooms were fitted up and the desired temperatures secured. The Eastern experiments were conducted by L. L. Van Slyke, G. A. Smith, and E. B. Hart, of the New York Agricultural Experiment Station. The cheese was cured in New York City, arrangements having been made with the Merchants' Refrigerating Company to provide special rooms and take care of the different lots of cheese. SELECTION OF THE CHEESE. In order to cover the cheese-producing country of the East and West, samples were purchased in a number of the States in the neighborhood of each experiment. In the West cheese of three types were secured: I. Close-bodied, firm, long-keeping type, suitable for export trade (typical Cheddar). II. Sweet-curd type. III. Soft, open-bodied, quick-curing type, suitable for early consumption. Type I represents the class of cheese that is especially manufactured in Wisconsin; while, as a rule, Type III represents the kind of cheese that is chiefly made in Michigan. The representatives of the sweetcurd type were taken from Iowa and Illinois, although this class is made to some extent in all sections. |