^ UNITED STATES DEPARTMENT OF AGRICULTURE BULLETIN No. 669 Contribution from the Bureau of Animal Industry JOHN R. MOHLER, Chief Washington, D. C. November 18, 1918 THE MANUFACTURE OF NEUFCHATEL AND CREAM CHEESE IN THE FACTORY By K. J. MATHESON and F. R. CAMMACK Of the Dairy Division CONTENTS Important Factors in Successful Produc- tion 1 I'he Manufacturing Process 2 Methods of Packing 11 Yield of Cheese per Hundred Pounds of Milk 12 Experimental Work on the Manufactur- ing Process • 12 Experimental Work on Keeping Qualities of the Cheese 21 Summary 27 WASHINGTON GOVERNMENT PRINTING OFFICE 1913 D« Of B* NOV 30 Itii ^ '-a'7/ UNITED STATES DEPARTMENT OF AGRICULTURE JTU^^W"*. 1 BULLETIN No. 669 Contribution from the Bureau of Animal Industry JOHN R. MOHLER, Chief S\Jf'''^'WL. Washington, D. C. November 18, 1918 THE MANUFACTURE OF NEUFCHATEL AND CREAM CHEESE IN THE FACTORY. By K. J. Matheson and F. R. Cammack, Of the Dairy Division. CONTENTS. Page. Important factors in successful production. . . 1 The manufacturing process 2 Metliods of packing 11 Yield of cheese per hundred pounds of milk. . 12 Page. Experimental work on the manufacturing process 12 E.xperimental work on keeping qualities of the cheese 21 Summary 27 IMPORTANT FACTORS IN SUCCESSFUL PRODUCTION. When Neufcliatel and cream cheese are manufactured on a com- mercial scale it is important to use methods that will assure a uni- form, attractive, and wholesome product. Very little detailed in- formation dealing with the making- of Neufchatel cheese upon- a factory scale is available. In fact, in many cases the trade secrets of this branch of the dairy industry have cost manufacturers large sums of money. In outlining the methods of making the cheese several factors should be taken into consideration : 1. Quality of raw material. 2. Healthfulness of the cheese. 3. Economical use of labor and equiitment. 4. Reduction of losses to a minimum. 5. Conditions influencing the keeping quality of the cheese. QUALITY OF MILK. Formerly starters were not used in the making of Neufchatel cheese on a commercial scale. Under such conditions a mixture of night's and morning's milk was deemed more desirable than fresh milk. With this system the normal fermentations were often super- seded by gassy fermentations in warm weather and especially' in the 70784°— 18— Bull. 6G9 1 . 1 2 BULLETilSr 669, U.. S. DEPARiTMENT OF AGBICUL.TTJRE. spring months. This resulted in injury to the quality of the cheese and also greatly reduced the yield. At present practicall}^ all manu- facturers pasteurize the milk, necessitating the use of a starter, but thereby preventing abnormal fermentations and insuring a uniform product from day to day. In- either case, whether pasteurized or not, a sure and rapid development of the acidity is necessary in order to make the- cheesfe successfully^ FACTORY SANITATION. The room where the milk and cheese are handled should be con- structed with a view of maintaining strict cleanliness. Cement walls and floors are almost imperative if they are to be kept in a sanitary condition by daily washing and flushing. The water used in the factory should be filtered or should be obtained from a source free from all possible contamination. The equipment and utensils in a soft-cheese factory should be so arranged and constructed as to be easily cleaned. Only such apparatus as is daily needed to facili- tate the rapid and proper handling of the milk and cheese should be left in the workrooms. Precautions should be taken also to have all heating and cooling pipes below rather than above the place where the cheese is drained, so as to gua.rd against falling par- ticles of dirt and rust. All windows and doors of the factory should be provided with fine-meshed screens, to keep out flies and. other insects. THE MANUFACTURING PROCESS. The process of making Neufchatel and cream cheese in the fac- tory is essentially the same as that on the farm, as. described in Farmers' Bulletin 960. The handling of large quantities of milk, however, requires more elaborate and extensive equipment in order that the numerous operations may be performed rapidly and effi- ciently. Vats of about 600 gallons' capacity are commonly used for heating the milk. After a preliminary warming with the addition of rennet and a starter, the milk is run directly into shotgun cans holding about 4 gallons each, which are filled by means of a con- necting pipe. The cans are then set side by side in a concrete-walled room, commonly known as a cellar, or, if the room is small, placed one upon another. Along the sides of the cellar are steam pipes that regulate the temperature so as to induce proper fermentation. After the milk has ripened for 15 to 18 hours the coagulum is poured upon draining cloths supported by means of special drain racks placed side by side. After a large part of the whey has drained off, the corners of the cloths are folded together, tucked in, and the re- sulting bags placed on ice in order to prepare the curd for pressing. After pressing, the curd is salted, ground by means of a roller or MANUFACTURE OF NEUFCHATEL AND CREAM" CHEE&E. 3 other mixing device, and sent through a special molding machine which molds and cuts the cheese to the proper size. The cakes of cheese are then wrapped in tin foil or aluminum foil and boxed for shipment. The details of the various steps of manufacturing are as follows : PASTEURIZATION. The principal reason for pasteurization in the making of soft, un- ripened cheese is to remove the danger from disease-producing organ- isms. In working with cheeses of the Neufchatel group, Schroeder ^ found that of 32 samples of Neufchatel cheese tested none were in- fected with tubercle bacilli ; of 31 samples of cottage cheese tested 1 was infected with tubercle bacilli ; of 131 samples of cream cheese tested 18 M^ere infected with tuber'cle bacilli. In each case the tubercle bacilli founcLwere of the bovine type. The desirability of pasteuriz- ing milk for the making of such cheese is therefore evident. If proper pasteurization is practiced, together with the use of an efficient starter, there are a number of other advantages, which may be enumerated as follows: 1. The cheese produced is more nearly uniforui. 2. Gassy feniientations accompanied witli excessive curd losses are prevented. 3. The yield is slightly increased. 4. Cheese of uniformly higher quality with less (hiiigcr of l)itterness when aged is insured. 5. Milk for making the cheese can be held for a longei- time. It is unquestionably true that cheese nuide from unpasteurized milk and Avithout the use of a starter possesses a characteristic aroma at first not so readily observable in the pasteurized cheese, but the difference becomes less marked in the course of a few da^s. The initial aroma may be produced by some volatile substance that is partially driven off in the course of the pasteurization. To obtain a safe product, however, it seems desirable either to use milk from tuberculin-tested cows, or to pasteurize the milk and use a starter, even though the initial flavor is sacrificed to a slight extent. Milk may be pasteurized by either the holding or the flash system of pasteurization, although the first mentioned is the better. Where new factories are being established, the holding system is always recommended. With the flash system the milk is heated to 165° or 170° F, for a moment and then cooled to the desired temperature. With the holding system the milk is heated to 145° F. and held at that temperature for 30 minutes. For small-scale operations the milk may be pasteurized by heating in a jacketed vat and cooled by water without being -removed from the vat. For large operations the most economical kind of pasteurizer not only pasteurizes but cools and 1 " Public Health Studies Concerning Cheese," a paper read before th-e International Association of Dairy and Milk Inspectors by E. C. Schroeder, at Washington, D. C, Oct. 17, 1917. 4 BULLETIN 669, U. S. DEPARTMENT OF AGRICULTURE. mixes the milk. From the standpoint of quality of the cheese there is practically no difference between the two processes; and in either case the milk, after pasteurization, should be cooled quickly to 80° F. for Neufchatel or 83° F. for cream cheese. It is possible so to regulate the flow of brine or water in the coil as to bring the temperature of the milk to the desired point without rew arming. STANDARDIZING THE MILK. It is desirable to use whole milk testing 3| to 4 per cent for making Neufchatel, while for cream cheese sufficient cream should be added to the milk to bring the resulting mixture to .from 6 to 8 per cent fat. In some factories the milk is skimmed and cream enough is added to obtain a 6 or 8 per cent milk. The milk always should be standardized before pasteurization. With 4 per cent milk available, if one-third of the quantity is run through a cream separator and the resulting cream added to the remaining two-tjiirds, milk testing approximately 6 per cent is obtained. If the milk tests only 3 per cent it will be necessary to separate one-half of the quantity and add the cream to the remaining half. For extensive operations it is advisable to use a Babcock tester to standardize the milk accurately. The following diagram illustrates an easy metliod of determining the proportions of milk and cream of different per cent of fat needed to make up 6 per cent milk : Cream and milk on lunul. Proportions to tie uscfl. 34 per cent cream. 2 parts cream. Six per cent milk desired. 4 per cent milk. 28 parts milk. The desired p'er cent of fat, in this case 6, is placed in the center of the square. At the upper left-hand corner the per cent of fat in the available cream is placed, in this instance 34. Immediately below, in the lower left-hand corner, the per cent of fat in the available milk is placed, which in the instance cited is 4. Next sub- tract diagonally across the square the smaller from the larger num- ber and place the difference in the upper and lower right-hand corners respectivelv. In the upper right-hand corner 2 represents the number of parts of 34 per cent cream, and in the lower right-hand corner 28 represents the number of parts of 4 per cent milk neces- sary to make 6 per cent milk. If it is desired to make up a definite quantity of 6 per cent milk, for example 60 pounds, the procedure is as follows: Two added to MANUFACTURE OP NEUFCHATEL AND CREAM CHEESE. 5 28 makes a total of 30 parts of 6 per cent milk. The quantity of 34; per cent cream necessary is ^ X 60, or 4 pounds, while the quan- tity of 4 per cent milk is -f^ X 60, or 56 pounds. STARTERS. A rapid development of acidity is necessary. The addition of commercial lactic starter aids in hastening subsequent drainage and checks objectionable fermentations. From 1 to 1| per cent of starter is recommended for best results. The curd of the starter should be broken up into a fine condition before adding it to the milk. When pasteurization is practiced sufficient starter must always be added to make the development of acidity certain, and tliere is little danger of developing the acidity too rapidly. A slow-acting or impure starter is sure to cause disappointment and losses. Too much attention can not be given to keeping the starter vigorous and pure. Satisfactory starters may usually be obtained from any reliable starter company. The method of handling the starter on a factory scale may be outlined as follows : 1. Place a clean agitator in a shotgun can that is bright, clean, and free from rust. (A 2-quart fruit jar and a long-handled spoon will be satisfactory for a small-scale operation.) 2. Put a quart of fresh skim milk in the can or jar and heat to 175° F. and hold at that temperature for 30 minutes. 3. Cool the milk to 75° F. and add the entire contents of a pack- age of solid or liquid commercial starter, stir vigorously, cover, and set away until coagulation takes place. 4. Hea.t several gallons of skim milk in a starter can or in a 10- gallon milk can to 175° F. and hold at that temperature for 30 minutes, then cool to 75° F. 5. By means of an agitator break up the coagulum in the shot- gun can into finely divided particles and then pour it into the starter can or 10-gallon milk can containing the pasteurized skim milk. 6. Each day repeat steps 4 and 5, but instead of preparing a fresh starter as in 1 and 2, use about" 1 quart of the starter prepared the day before to each 10 gallons of pasteurized milk. TEMPERATURE FOR SETTING. The temperature at which milk. is usually set to ripen is 80° F. for Neufchatel and 83° F. for cream cheese. In certain factories the milk is set at 78° F. and the temperature is raised seve-ral degrees after coagulation has taken place. Experiments have demonstrated that temperatures from 75° to 85° F. for setting may be safely used. The object of the higher temperatures for setting is to favor a rapid coagulation, which in a measure reduces subsequent fat losses by quickly cheeking the rising cream. The temperature of setting de- 6 BULLETIN 609, U. S. DEPARTMENT OF AGRICULTURE. termines to a great extent the softness or firmness of the curd. Under normal conditions it requires from 45 to 60 minutes to curdle milk; the exact time to set a given lot of milk will, of course, depend upon the temperature, acidity, rennet, and composition of the milk. RENNET OR PEPSIN. Commercial liquid rennet, one-third of an ounce, or five-sixths of a gram of powdered pepsin, is added to each 1,000 pounds of milk. The rennet should be diluted in a half pail of cold water, or if pepsin is used, the powder is first dissolved in a little cold water and then handled in the same manner as rennet. There is some ad- vantage, in the case of cream cheese, in using half an ounce of liquid rennet or 1 gram of powdered pepsin per 1,000 pounds of milk in- stead of the quantities specified. Sometimes powdered rennin is used as a curdling, agent, in which- case the quantity depends upon its strength. One gram of powdered rennin i-s usually equivalent to' 4 or 5 grams of liquid rennet. The powdered pepsin or powdered rennet should be weighed, on an accurate balance and then dissolved in 20 times its weight of water warmed to 105° F. The solution is. then poured througli a strainer cloth into a dipper of cold water in order to remove any solid par- ticles. Under no circumstances should powders be dissolved until needed for use. Pepsin has given nearly as satisfactory results as rennet and is less expensive. All liquid curdling agents should be kept in a cold phice in dark- brown bottles which are kept tightly corked. FILLING THE CANS. After being pasteurized and. cooled down to 80° or 83° F. and the curdling agent added, the milk is drawn off from the faucets of the setting vats, which should be placed close to the cellar. The work must be conducted rapidl}^ so that the contents of the va.t may be removed within half an hour, to avoid agitating the milk after it has. begun to set. Unless a sanitary connecting pipe is used in filling the shotgun cans it requires several workers to remove them as rapidly as they are fiJled. If not very carefully cleaned and thoroughly sterilized daily, the connecting pipe can not be kept in sanitary condition, and its uSe should be avoided. The shotgun cans are usually filled in the forenoon in order that the curd may be ready for drainage the following morning. DUMPING THE CURD. The following moming, if the fermentation or ripening has progressed satisfactorily,, there should be about a quarter of an inch of whey, which is sufficient to form a scum on the surface of the curd. This is a fairly accurate sign of a proper fermentation, while MAiSrUFACTURE OF NEUFCHATEL AND CKEAJVL CHEESE. 7 the absence of whey on the surface and a puffed appearance of the curd indicate either a poor starter or improper pasteurization. Usually between 5 and G a. m. the cans of curd are poured upon the cotton-sheeting draining cloths which were spread over the racks the previous evening. In emptying the shotgun cans the con- tents are poured carefully against the side of the drain cloth rather than in the center, in order that any cream which may have risen may not be leached unnecessarily by the rapidly escaping whey. The contents of each can should be so poured as to break the jelly- like curd or coagulum as little as possible. No curd should be left adhering to the sides of the can. If the curd has a tendency to stick, Pig. 1. — Gassy curd and normal curd. which is more often the case when pasteurized milk has been used, it may be loosened by striking the can against the floor. Wlien emptied, the shotgun cans should be washed immediately, first in cold water and then scrubbed thoroughly in hot water con- taining washing powder, after which they should be rinsed again with warm water and thoroughly steamed. The cans may be transported from the place of setting to the draining racks either by overhead trolley or by hand; in either case several men are needed to do the work promptly. DRAINING. The draining should be completed in about three hours, depending somewhat upon the kind of cheese, for cream-cheese curd drains much more slowly than partially skimmed Neufchatel curd. A gassy curd drains much more rapidly than a normal curd, and the losses of curd are excessive. 8 BULLETIN 669, U. S. DEPARTMENT OF AGRICULTURE. For the first two hours the coaguhim is left undisturbed, in order that the free whey may escape and that the curd may acquire a con- sistence that is not readily broken to pieces. Finely broken curd is unfavorable for drainage. During the last hour the curd is worked toward the center of the cloth by means of a tin or wooden ladle. The ends of each drain cloth are then loosened and the cloth and its contents placed in a boxlike rack which rests upon a wide, flat board, after which first the sides and then the ends of the cloth are alter- nately folded over the curd. The end pieces of the cloth are then tucked in. giving each drain cloth and contents a baglike appearance. Fig. 2. — Draining equipment in a modern factory. After the preliminary draining just described the manner of han- dling the curd in the bags will depend upon how soon they are to be pressed. If the cheese is to be pressed the same day the pro- cedure is as follows: After draining for 30 minutes the bags are piled one upon another in a rack, where they remain for about half an hour, after which the bags from two racks are placed in a single pile. Usually two or three racks are placed one above another aaid the bottom 'sticks are removed. For about an hour the three or four dozen bags remain undisturbed, save for a rearrangement which occurs once during the period, when the position of the bags is reversed. When the curd is not pressed until the following day, the bags of curd are placed on ice at once. MANUFACTURE OF NEUFCHATEL AND CREAM CHEESE. 9 ICING. When the cheese is made in large quantities, the bags of curd are always in alternate layers of cracked ice prior to pressing. Usually a large rectangular box about 3 feet high, 8 feet long, and 3 feet wide is provided in which alternate layers of ice and bags of curd are placed. Under the first system of draining, the curd may be cool enough in a few hours to permit pressing, while, if the pressing is not to be done until the following day, the bags are left on ice overnight. The object of chilling is to harden the curd so that it does not so readily pass into the meshes of the drain cloths and in- terfere with draining, and also to give it sufficient body to be molded. PRESSING. After chilling, the bags of curd are placed in a lever press pro- vided with ratchet and pawl, where firm but increasing p'ressure is applied gradually, in order to allow the escape of whey and incor- porated air. Without this precaution there is danger of applying so much pressure as to break the drain cloths, which is more liable to occur at first with a comparatively light pressure than later when more pressure is applied. The pressing should continue until a yield of 18 to 20 pounds per 100 pounds of milk is obtained for cream cheese and 11 to 16 pounds for Neufchatel cheese. This is equivalent to a yield per bag (30-pound unit of milk) of 5^ to 6 pounds of cream cheese and 4-| pounds of Neufchatel. The acidity of the whey at the beginning of pressing is about 0.50 to 0.55 per cent. WORKING AND SALTING. After pressing, the cakes of curd are salted and worked by ma- chinery into a more or less buttery consistence. This is accom- plished by either of two machines, namely, (1) a grinding machine consisting of a hopper and two grinding cylinders, which are rotated in opposite directions b}^ power, and (2) a bread mixer or similar mixing device, which consists of a tilting mixing box provided with knives revolving in opposite directions, operated by electric powder. Salt is sprinkled on the cakes of curd, usually at the rate of 1 pound of salt to 100 pounds of curd. Some numufacturers salt as high as 1^ pounds to 100 pounds of curd ; the amount of salt to use will of course depend upon the trade demands. Either of the machines mentioned is used to distribute the salt uniformly throughout the curd; the rest of the work necessary for a cheese of smooth consist- ence is to be performed by the spiral screw of the molding machine. The mixer type gives the curd a very soft consistence, so much so that it must be kept at a low temperature for several hours or over- night before it will be in a fit condition for molding. On the other hand, the grinding machine is less vigorous in action and handles 70784°— 18— Bull. 6G9 2 10 BULLETIN 669, U. S. DEPARTMENT OF AGKICULTTJRE. the curd more rapidly. In this case, after coming from the machine, the curd is ready to mold at once. The cheese, as it comes from either the mixing or the grinding machine, is transferred to the refrigerator or to the molding ma- chine in large cans or square wooden boxes holding from 80 to 100 pounds. MOLDING. A special machine designed for molding may be purchased and is in use in most of the large soft-cheese establishments. The curd is placed in a hopper from which a spiral screw forces it into a molding tube that delivers it to an automatic cutting device, which cuts the curd to the desired lengths for wrapping. Operated by skilled work- FlG. -Curd mixer and press men with the curd in the proper condition, the machine can mold and cut from 2,400 to 2,500 Neufchatel cheeses an hour, and cream cheese in like proportion. Two conditions are necessary for the proper working of the ma- chine: (1) The curd must have the proper temperature, about 50° F. ; (2) the curd must not contain too much moisture. A yield of from 18 to 20 pounds of cheese per 100 pounds of milk seems most satis- factory. With a lower yield the cheese runs through with difficulty ; with a higher yield it is often too mushy to handle satisfactorily. Only one person is actuallj'^ required to operate the machine, although several are necessary for wrapping. The curd should be worked from the hopper into a feed screw by means of a ladle. The issuing roll or ribbon of cheese is automatically cut to the desired size and car- MANUFACTURE OF NEUFCHATEL AND CREAM CHEESE. 11 ried hj means of a canvas conveyer, which is about 10 inches wide and 12 feet long:, to the place of wrapping. Along either side of the con- veyer are seated girls who dexterously remove, wrap, and replace the cakes of cheese. At the end of the conveyer the wrapped cakes are removed by a girl who places them in suitable boxes. Pimiento-cream, or pimiento-olive cream cheese is handled a little differently. The curd and pimiento peppers are first run through a meat chopper and are then ready to be sent tlirough the molding machine. A cylindrical Neufchatel attachment in the sliape of a tube sufficiently small to pass to the bottom of a 4-ounce glass jar is used for filling purposes. The curd is forced into the jars until they are completely filled, when they are scraped over the end of the at- tachment so as to give a smooth appearance to the surface of the end and leave few if any air spaces throughout the curd mass. Some- times the tops of the jars are leveled off l)y means of a milk cap. -Wrapping and paekini; Xoufchatel from the molding macliiuc. METHODS OF PACKING. The cakes of Neufchatel and cream cheese are wrapped in tin or aluminum foil with parchment paper. The foil when purchased is cut to the proper size and stamped with the desired brand and weight. The commercial life of the cheese may be considerably lengthened by skillful and careful wrapping. Each wrapper should be drawn se- curely about the cheese before it is placed in the wooden box (" flat ") in single layers, and each package should be well shaped and present a bright, attractive appearance. Cream cheese is packed a dozen in each box, but the Neufchatel cheese is marketed in boxes containing 1 or 2 dozen cakes, and sometimes 25, to the box. Often the cheese is shipped in tubs or cans from the factory to the distributing center before molding. Such a system reduces labor 12 BULLETIN. 669, U. S. DEPARTMENT OF AGRICULTURE. and freight charges to a minimum, and the keeping quality of the product is likewise improved. The glass jarsof pimiento or olive-cream cheese are first covered with paraffined disks of paper cut to the proper size and then with screw caps. SIZE OF PACKAGES AND PRICES. Standard Neufchatel packages in tin foil are about 1^ inches in diameter and 2-i- inches long, and weigh from 2^ to 3 ounces. At present they retail at about 7 cents a package, while the wholesale price is about $1.40 a box of 25 cheeses. The cream-cheese packages in foil are 3 inches b}- 2 inches by 1 inch and weigh from 3 to 3| ounces. Such packages retail at about 15 cents each; the wholesale price is from $1.30 to $1.40 a box of 12. The pimiento cheeses, in glass jars, weigh 3^ ounces net and retail at about J 5 cents a jar. The size of packages has been fixed by experience. Larger pack- ages ha^e been tried by manufacturers, but the practice was quickly discarded as being impracticable. A small package of cheese may be consumed at a single meal, whereas larger packages would require special and effective refrige'\ition to prevent the development of mold and deterioration of flavor. YIELD OF CHEESE PER HUNDRED POUNDS OF MILK. The yield of Neufchatel and cream cheese varies with the composi- tion of the milk and the metJiocls employed in making. One hun- dred pounds of milk containing 4 per cent fat yields from 14 to 16 pounds of Neufchatel cheese, and milk containing from 6 to 8 per cent fat yields from 18 to 20 pounds of cream cheese. Higher yields some- times are obtained, but cheese with a much higher 3'ield is too soft to handle satisfactorily. Pasteurization ordinarily increases the yield from one-half to 1 pound per 100 pounds of milk. Usually when a lower yield is obtained the cheese is gummy and unattractive to the average buyer. If made from milk containing less butterfat correspondingly lower yields are obtained, as is the case when Neuf- chatel cheese is made from partially skimmed milk, such as one- third, one-half, or even two-thirds skim. EXPERIMENTAL WORK ON THE MANUFACTURING PROCESS. Experiments were conducted to determine the most efficient methods to follow in the manufacture and subsequent handling of the Neuf- chatel group of cheeses. The manufacturing phase of the work requires a consideration of the methods that will (1) reduce losses to a minimum, (2) insure a safe product, and (3) make the cheese most economically. The second phase of the work considers the MANUFACTURE OF NEUFCHATEL. AND CREAM CHEESE. 13 A^arious factors which ma.y influence the keeping qualities of the cheese. Very little previous work has been done along this line. A study of each of the important steps has been fount! necessary to gather definite information with regard to the most efficient sys- tem of manufacturing, which includes a consideration of three fac- tors: (1) Initial condition of curd; (2) rapidity of drainage ; (3) fat losses. The following subjects have been cons-iderecl: 1. Effect of different quantities of rennet. 2. The use of pepsin as a substitute for rennet. 3. Effect of temperature on the malving process. 4. Effect of starter on tlie making process: 5. Effect of pasteurization and starters on tlie making process. 6. Effect of pasteurization on the moisture content of the cheese. 7. Effect of homogenization on the making process. EFFECT OF DIFFERENT QUANTITIES OF RENNET. A definite quantity of rennet is necessary in the manufacture of the Neufchatel group of cheeses in order to obtain the characteristic curd, which must be neither too soft nor too brittle. The high cost of rennet requires that the curdling agent be used judiciously. So far nothing has been published regarding the most efficient and eco- nomical quantity of rennet to use for these cheeses. The quantity of rennet necessary depends not only upon the- rate at which the whey is expelled, but also upon the breaking up of the curd and upon the fat losses caused thereby. To determine this point, commercial liquid rennet in proportions varying from one-fourth of a cubic centimeter to 4 c. c. per 100 pounds of milk was used, with the results shown in Table 1. In each case 250 c. c. of lactic starter was a.dded to each 30-pound unit of milk. Thirty pounds of milk was used in each of the experiments. All the whey was collected and measured from the time the coagulum was poured upon the draining cloths until the curd was in fit condi- tion to ice, or in some cases for only part of that time. In any case the different parts of each sample were handled in the same manner. Fat determinations were made of each unit of a sample. It is noticeable that the losses of fat increase with the higher per- centages of fat in the milk, and there is also a slight increase in losses with the higher proportions of rennet. The losses of fat in the whey appear to be greatest when the large quantity of rennet causes the coagulum to be so brittle that it appears to break up more readily than when the lower proportion of rennet is used. Rennet in as small quantities as one-half of a cubic centimeter gave fairly satis- factory results with Neufchatel cheese, though the curd of cream cheese appeared somewhat too moist. When 3 or 4 c. c. of rennet per 14 BULLETIN 66&^ U. S. DEPARTMENT OP AGRICULTURE. 100 pounds was used, the curd was too dry to be' satisfactory and the draining period was not shortened. There is a gradual increase in the whey expelled with the larger quantity of rennet until about 4 c. c. is used, when the drainage appears to be checked slightly. Rennet used at the rate of from one-half to 2 c. c. per 100 pounds seems to be the most satisfactory for Neufchatel cheese, whereas 1 c. c. to 2 c. c. seems most desirable for a like (juantity of cream cheese. MANUFACTUEE OF NEUFCHATEL AND CREAM CHEESE. 15 te ^ o i^- w , ^ O * S' ■ 1 fm-^ —1 Lh O 2 a : T3T)'^ n fl o • o o o •I-S 'u o ; o o o So -, » ■ o '• ooo S ; g ; lO" j 1/fiOO ■M&H « ■o lOOiO M || *i^ ' o co-^ -^ a ft, : S 0; O o ^ • g^ 3 j>i (in'^J a d-d ■^'3 o +3 " o •°- s •c o rrr- " O H OOHH S^fe CO c^ >v « ; o oooo g; Ui -^ lO r^t-- «3 05 •Ss'a oioco«» m" » > ^3 £ . tcT o^t^iCr-T 03 03 ^ - O ; lO >ooo M ■^ M M coco ^ -^ (So *-, ; 6 ■^ • t.-. o ^ i^ • • > -,>> o a |3 l-rt I 1 »- ■o '^ O ■ o o o o o ■c ■ o o o o o "g" o :OOOr^H So <^ >> 1 • s ■ igoggo ^»? •O CD CN CO O t»s;t ^^^3 • tCo'r-''i>-''i>^ 03 ^ Z^ ^ lOOJC c^c^ c XJl fSS ft, o t*-. O ^ i^ '.>. fe^- 13 t: rr)T3'^ % c ^ o o o o o o o • °*i K o o o o o o -M » CS iM (N §n CO CO OS =0 yi^ I"- m *^ lO lO lO iC lO lO C3 it: }^ ^"^^ r''^ ^ ft^ O > -. ! ; jo • • 'o 5 ^ ■ c u ^ e c3 ,; »0 -o3 1^1 g . .lO . .C£ i ;oo" • ;c 3 '. '■ "SP^ ft. 1 1 iio 1 ; iio 1 IiO 1 '. c s ■^ ^ ■ . . « • ; ; " . .CO ; ;^ « . (£! o ; ; ;d j j J ' -S : i-j : : : ; : : i-s i : o . ,11 I !'o ' ' • . • ;:>;>:: ' ' • X +3 o ; :a : ; ;^ : . . o • ■ • o • I l'^ ! '. • • C 'sl^ • ■ o • • • o • ' o ■^sa O : :eh ; : :o ; ', :s j ; ■ :h p.ftp< g"^ t>i -. i !o • ■ 'o • 1 !o • • • o O 1- -^ s . .CO • . 'O • o3 . CO ^-i . .lO • ■ 'C^ • . . lO . . -C3 ; ;oo" ; ; • oT ^f=H P '^ ^ ^ • ■ -r . . 'CO ■ I 1^ i 1 1 !" ; 1 • o pi, o Su . .o . . , ■ , rt ft, 'A •« i ! ! ! o 1 .' I o . . . . o ... 3 id '.'.'. '.'^ '.'.'. ;3 o ; ; ; ; "HjJ ; . ; ss ; 1 1 .'^-o '■'V '■ i-^ : i-S s'a "-*2 o : : : :ra ;8 : . o • • o o^H o ■ o ■ • o :o : :e ;>■ - ; I 1 !o -o • o t- +j S . . . .t^ . lO ■ . . . . t^ .1?^ ' ; S ■ .8 1 l-i C3 . . . .cd" ;^ ; ■oT ; 'o" "S M ^, . ; : is is : 1°. i i° f^ ° .' .' .'o •' ■ •' tf ft^ • '-H 1 o id ii ': ', ': ; : : 3 1 ! ! ■ ! ! ^ fe « :§s a : : ; ^ : : o : ;•« :d " ; ; xT ; jod" ;0> .o ' ^ • o • ' o ' '>ra 'o « ft. «... « 1 1 d • • • ' ; ; N) . . c^ . OJ 'd O o id c : 3 ; ; ; ; • >. • •3S fi :a : : : :^ : : .'t) : • •S : ^§s +j o o c :o : : : :§ : : :8 : ; o • o • — 1-H o »^ o t- O . &H :h : : : :o ; : ;o : : H : >> ■"• ec'O lo • • '■'■<=> : : :© : : o ■ g;^ .CD . . ■ .O) . r^i . . * • CO ! 1 lo • ■ io '■ |S.| i ^ .' ; ; ; '^ • ; ;nd 2,000 pounds' pressure. The homogenized and unhomogenized samples of the same percentage of fat were taken from the same lots of milk. Cream cheese was then made in the usual way and the fat losses de- termined. MANUFACTLTRF OF NEUFCHATEL AND CEEAM CHEESE. 21 Table 1.— Effect of homogenization on fat losses in cream, cheese. Sample No. Loss Fat in of fat. milk. Per ct. Per ct. 0.015 6.2 .020 6.2 .020 6.2 .025 6.2 .015 6.2 .200 6.2 .04 6.0 .150 6.0 Temperature of setting. Quan- tity of Rennet added starter per 100 unit. pounds. C.c. C.c. 250 1 250 250 250 250 250 250 250 1 Criticism of curd. 1. Homogenized 2. Homogenized 3. Homogenized 4. Homogenized 5. Homogenized 0. Not homogenized 7. Homogenized 8. Not homogenized 30° C. (86° F.) ....do ....do ....do ....do ....do ....do ....do Good curd, whey very clear. Do. Do. Do. Do. Good curd. Good curd, whey very clear. Good curd. There is a slight advantage in homogenization in reducing the fat losses, but it is doubtful whether there is i-ufRcient gain by this process to justify the added cost of sucli treatment. EXPERIMENTAL WORK ON KEEPING QUALITIES OF THE CHEESE. Neufchatel and similar cheeses are ver}^ perishable products, the length of time that they can be kept depending upon the manner in which the cheese has been handled and the nature and quantity of the added ingredients. In the study of this problem the following points were considered : 1. Influence of yield on quality. 2. Influence of salt on keeping quality. 3. Influence of the holding system (,f pasteurization. 4. Effect of homogenization and of the flash and holding systems of pasteurization on keeping quality. 5. The use of powdered pepsin. 6. Influence of pimiento peppers. INFLUENCE OF YIELD ON QUALITY. In order to study the influence of yield upon quality, cream cheese was made in the customary manner, with the exception that some samples were pressed more than others. The samples were made to give yields varying from 15 to 24 pounds per 100 pounds of milk, and some were pasteurized, while others were not. The samples were kept at 10° C. (50° F.) and 20° C. (68° F.) and were judged by a number of persons at various intervals, with the residts shown in Table 8. In this and succeeding tests (Tables 9 to 13) the number of per- sons judging the cheese varied from» time to time. This was un- avoidable, as it was not practicable to have the same number each time. 22 BULLETIN 669, U. S, DEPARTMENT OF AGRICULTURE. Tablk S. — The effect of yield upon kecpinij qualiti/ (>f crcdm cheese in storat/c. [Samples held at 10° C. (50° F.).] Sample 1. Sample 2. Sample 3. Yield from 100 pounds of Yield from 100 pounds of milk, Yield from 100 pounds milk. not pasteurized. of milk. M 1 w -iJ ^ ' 5^-«" (S o 05 o § (-■O -» S w m a 1 ^■«- ft'g a_- ??-^- 1 o o poimds teurizt pound teuriz( "3 o <1 13 i P. o ft i ft 73 o at P< S3 a o 3 3 al 9 3 o » < s 00 ta 00 Cu S c^ lO 2: ■< IM Days. Days. Dai/.t. 4 12 3 1 1 2 1 1 1 1 1 4 1 3 1 8 2 3 2 1 4 2 1 6 2 2 2 2 11 1 2 2 1 6 2 8 2 3 1 T 15.... 1 3 2 • 2 7 3 1 1 11 1 2 2 1 18 2 2 1 2 8 1 1 13 1 2 1 1 21 3 3 2 1 11 3 1 15 2 2 2 2 25.... 2 2 2 1 16 1 1 IS 2 3 2 1 1 I The figures 1, 2, and 3 in body of table Ladicate the number of people expressing a preference for partic- ular samples of cheese. In this and subsequent tests it was impractical le to have the same numler of judges for each set of samples. The samples that yielded highest appeared slightly more acid than the low-yield cheese, although the differences were not especially marked. The low-yield cheese seemed much more " gummy " and more quickly developed a Cheddarlike flavor after being kept several days. The majority of the judges preferred the cheese giving a yield of 18 pounds per 100 pounds of milk, while nearly as many preferred the cheese giving a yield of 21 pounds. With a yield of much more than 20 pounds per 100 pounds of milk, much difficulty will be ex- perienced in running the curd through the molding machine. Be- cause of that fact there is little danger of manufacturers making too moist a cheese. INFLUENCE OF SALT ON KEEPING QUALITY. In order to study the influence of salt in cheese upon its keeping quality, cream cheese was made in the usual way from milk testing 6.2 per cent fat, and portions were salted at the rate of ^, f , 1^, and 1^ per cent. The cheese was wrapped in tin foil and held at 10® C. (50° F.) and 22° C. (71.6° F.) and examined at various periods. Table 9 gives the result of the experiment. MANUFACTURE OP NEUFCHATEL AND CREAM CHEESE. 23 Table 9. — Influence of salt on keeping quality of cream cheefte. Held at 10° C. (50° F.) Held at 22° C. (71.6* F.). Age of cheese. Per cent of salt. Percent of salt. 1 2 11 IV 1 3 IJ H Days. 3 oooooooo 5 3 1 2 1 1 1 3 I 3 2 1 2 1 3 1 1 3 2 1 3 3 5 4 5 6 2 8 11 15 19 24' 28 1 1 The figures in body of table indicate the number of people expressing a preference for a particular kind of cheese. Most people seem to prefer a cheese containing" from three-fourths to 1^ j)er cent of salt. The cheese with one-fourth per cent salt was pronounced flat and insipid, while that with 1| per cent was usually considered too salty. The cheese with tlie one-fourth per cent salt spoiled more quickly than the other samples. When a few days old a slight bitterness developed in the cheese containing li per cent salt, while there was a distinct "off flavor" in the low-salted cheese. The cheese containing three- fourths and 1^ per cent of salt seemed to keep equally well. In general the lower proportion of salt, about three-fourths to 1 per cent, is to be preferred, because a higher per cent has a tendency to hide the finer flavors of the cheese. INFLUENCE OF THE HOLDING SYSTEM OF PASTEURIZATION. To test the keeping qualities of pasteurized and unpasteurized cream cheeses, some experimental cheese was made at a commercial factory and sent to the laboratory of the Dairy Division. The cheese was shipped by express and upon arrival was placed in rooms maintained by an electric control at 20°, 15°, 10°, and 5° C. (68°, 59°, 50°, and 41° F.), respectively. The initial heating of the milk was accomplished by running it through a pasteurizer where a temperature of about 62° C. (143.6° F.) was maintained for 35 minutes or longer. The milk was then run over cooling coils and cooled to the proper temperature for setting. One and one-half per cent of a vigorous starter was then added and the milk thoroughly stirred, after which the making process was carried on in the usual manner. The cheese was made from milk testing approximately 6 per cent fat. Samples were col- lected on successive days from the 200 or 300 pounds of experi- mental cheese, The keeping qualities of the pasteurized and unpasteurized cheese held at various temperatures were determined by submitting samples of both, marked only by numbers, to individuals who recorded their preferences, as shown in Table 10, 24 BULLETIN 669, U. S. DEPARTMENT OF AGRICULTURE. Table 10. — Keeping qualities of pasteurized and unpasteurized cream cheese in storage. Held at 20° C. (68° F.)- Heldatl5°C.(59°F.). Held at 10° C. (50° F.). Held at 5° C. (41° F.). 6 "A S. ft s % t o < Pi 1 o :2; i •S £1 P. o 1 3 o <6 i ft o •6 a 3 o o 2; g ft c 2 •6 3 1 Ph t4 3 B o 2; i ft o Days. 5 f "^ 9 i 12 14 I 1*J 7 10 12 14 f 4 6 8 10 18 8 7 4 3 3 6 c G 4 5 2 5 1 4 3 1 1 3 2 3 4 2 3 2 2 2 2 5 1 1 2 " 2 2 1 2 1 5 4 2 3 6 10 4 i] 1 4 4 2 8 1 6 2 1 1 2 3 2 3 3 1 1 1 2 2 3 1 2 1 1 1 2 2 1 2 3 4 1 9 4 I 1 6 4 2 1 1 11 1 1 1 G 1 1 ■A 2 1 1 2 4 2 G 4 2 2 3 2 1 1 3 3 4 2 1 2 3 5 3 4 2 2 I 12 2 3 4 4 4 1 1 The figures in body of table indicate the number of persons expressing a preference for n certain kind of cheese. The results seem to indicate that for about the first 10 days the preference was in favor of the pasteurized product for all tempera- tures. From 10 to 15 days the preference was for the pasteurized cheese held at 15° C. (59° F.) and 5° C. (41° F.) and for the un- pasteurized cheese at 10° C. (50° F.) and 20° C. (68° F.). In nearl}^ every case the texture of the pasteurized product was judged superior to the unpasteurized. The difference may be par- tiall}' accounted for by a small increase in water occasioned by the pasteurization. EFFECT OF HOMOGENIZATION AND OF THE FLASH AND HOLDING SYSTEMS OF PASTEURIZATION ON KEEPING QUALITY. To determine the most desirable system of handling milk prior to manufacturing it into cream cheese, so far as the keeping quality of the cheese is concerned, the following methods were studied : 1. Homogenization of the milk. 2. Flash system of pasteurization. 3. Holding system of pasteurization. 4. Checlv (where milk for cheese was neither homogenized nor pas- teurized). The samples of cheese compared were made from milk coming from the same vat, having therefore the same percentage of fat. When homogenization was practiced the milk was sent through the machine at 43° C. (109.4° F.) and with 2.000 pounds' pressure. Pas- teurization by the flash system was carried on at 76,6° C. (170° F.). MANUFACTURE OF NEUFCHATEL. AND CREAM CHEESE. 25 In the holding system of pasteurization two temperatures were used, 62.8° C. (145° F.) and 76-.6° C. (170° F.). ' The milk was heated to these temperatures, held for 30 minutes, and then cooled to the setting temperature. The milk was manufactured into cheese in the customary manner and the samples judged at intervals, as indicated in Table 11. Table 11. — Effect of homoiicnlzaiion and the flash and hoUlinf/ sifstciiis of pas- tciirlzatlon upon cream cheese in storage. Sample 1, held at- - Sampl B 2, held at— Sample 3, held at— 10° (50° C. F.). 15° (59° C. F.). 20° (68° C. F.). 10° C. (50° F.). 10° C. (50° F.). +^ ^ ^^ ^ _^ ^ c3 ■ ■s • iS • « • 03 • c3 • '6 ■6 ■6 a; ft. ■g^; -gfe •6 afL, -g;^ "Sfc," to S ■a 1 •a be o a 1 •a a o o 1 a 1^ 3 1 ® o o •a 1 a a; -H 3 1 z w A w Z w < a f^'" 1-4 M- A <; w S'" W" B- >5 Ds. Datj.t. Dav'''. ■,i 17 7 u ( 3 1 2 3 2 3 2 1 2 2 5 7 7 7 n 4 1 1 3 2 5 1 2 2 2 7 3 3 3 () 1 1 3 2 S 1 1 2 2 1 10 i ■1 4 7 1 2 1 11 1 1 2 2 1 1?1 3 4 2 3 4 2 S 9 10 12 15 1 1 1 1 1 17 ?1 ""1 ■ '1 '"1 ' ■ ' The figures in body of table indicate the number of persons expressing a preference for a particular sample of cheese. It ma}^ be noted that with the cheese froui homogenized milk results were not the same for samples 1, 2, and 3. In sample 1 there was a peculiarly bitter, rancid flavor, which in most cases, could be detected also in samples 2 and 3, but was much less in evidence. At other times Neufchatel cheese made from homogenized milk test- ing about 4 per cent fat had such an extremely rancid flavor as to render it unfit for market purposes. It appears, therefore, that there is greater danger of developing this characteristic homogenized flavor Avith milk of low fat than with milk of high fat content. The process of homogenization seems to be responsible for the bitter flavor observed in the cheese, for this bitter flavor is readily observed in the fresh cheese and does not develop further in storage. The only justification for the use of homogenization is to reduce the fat loss to a minimum. The process, however, is practically un- necessary, because under normal conditions the fat losses may be reduced nearly as much in other ways and there is far less danger of developing a bitter flavor in the cheese. There is very little difference apparently in the keeping qualities of creauj cheese made from milk pasteurized by the flash system as compared with the holding system. 26 BULLETIN, 669, U. S. DEPARTMENT OF AGRICULTURE. THE USE OF POWDERED PEPSIN. Owing to the red.uction of imports from Europe, remiet has risen to a very high price. Pepsin has been recommended as a substitute for rennet in the making of American cheese, but not for Swiss, Limburger, and other sweet-milk chees'e. Experiments have been carried out with the different forms of pepsin in the manufacturing of cream cheese. The cheese was handled in the usual way and then placed at different temperatures, as indicated in Table 12. Table 12. -Comparison of use of rennet icith powdered pepsin in nianufacture of eream cheese held in storage. Sample 1. Held at 10° C. Sample 2. Held at 20° C. Samples. Held Sample 4. Held Sample 5. Held at 10° C. (50° F.). (50° F.). (68° F. . at 10° C.(50°F.). at20° C.(68°F.). Unpas- Pasteur- Unpas- Pasteu- Unpas- Unpas- I^npas- teurized. ized. teurized. rized. teurized. teurized. tourizcd. .g .g .g .g ^g .g p ft ft ft ft ft ft ft o Oi ® ft ■ ft ft ft S ft ft S3 ?. T) to ■5 -a 'O V. .£3 T3 S ■O t. O § t ^ o t % O § ■^. o § ^ o ^ M M o o W) o M O "i o < « P4 pel Ok < tf Ph « (k -«^ « en Pimien- tol/20. 1 to 1/40. Cream cheese. Pimien- to 1/10. Pimien- to 1/20. Pimien- to 1/40. Cream cheese. 1 Days. f 4 6 8 13 18 28 I 43 f 10 17 21 27 35 14 9 5 5 3 3 2 2 8 3 2 2 2 2 1 1 1 3 9 3 • 4 3 8 5 3 2 2 1 Held at 10° C. (TO" F.). Held at 20° C. (68° P ). 6 3 4 3 4 1 5 2 1 1 2 1 1 1 The figures in body of table indicate number of people showmg preference for particular samples. A high percentage of piniientos seems to improve the keeping qual- ity of the cheese kept at 5° C. (41° F.) and 10° C. (50° F.). When held at 10° C. (50° F.) the pimiento cheese kept in good condition for a month, at which time it was edible, although some acidity had developed. No undesirable flavor had developed as in the case of the plain cream cheese. Either the pimiento acts as a preservative or it tends to cover up any undesira.ble flavor. When kept at 15° C. (59° F.) and especially at 20° C. (68° F.) b'oth the cream and the pimiento cheese became excessively sour in the course of a few days. There was a marked difference in this sour taste in the cheese lield at 15° C. (59° F.) and 10° C. (50° F.). Pimiento-cheese held at 5° C. (41° F.) was still edible after six weeks, although some of the surface of the cheese had to be removed. SUMMARY. The process of manufacture for Neufchatel and cream cheese is the same, except as noted. For Neufchatel use whole milk that tests about 4 per cent ; for cream cheese use milk standardized to from (> to 8 per cent butterfat. Obtain clean, fresh milk. Pasteurize the milk by heating to 145° F. for 30 minutes and then quickly cool to 80° F. for Neufchatel and. 83° F. for cream cheese. Add 1 per cent of a freshly made and vigorous lactic-acid starter. Add either commercial liquid rennet at the rate of one-third of an ounce or five-sixths of a gram of powdered pepsin to each 1,000 pounds of milk for Neufchatel cheese. For cream cheese use half an ounce of liquid rennet or 1 gram of poAvdered pepsin for each 1,000 pounds of milk. Either curdling agent should be diluted in half a pail of cold water before being mixed with the milk. 28 BULLETIN 669^ U, S, DEPARTMENT OF AGRICULTURE. Stir the mixture of milk, starter, und curdling agent and then run it into shotgun cans, 30 pounds in each can, and set away to curdle. In from 16 to 18 hours pour the contents of each can on cotton sheeting and allow to drain undisturbed for from 2| to 3 hours. Then work the curd to the center of the cloth, loosen the ends, and make each unit into a bag by folding over the cloth. Place the bags of curd between alternate layers of cracked ice for a few hours or overnight. Press the curd until each unit (bag) weighs 4^ pounds for Xeuf- chatel, or 5^ to 6 pounds for cream cheese. This means a yield for Neufchatel of 15 pounds and for cream cheese of 18 to 20 pounds per 100 pounds of milk, which seems most desirable. Remove the cakes of cui'd fi'om the drain cloths and salt at the rate of 1 pound to 100 pounds of curd. Run the curd through a grind- ing machine, or use a mixing machine and incorporate the salt uni- formly. Pass the curd through a molding machine Avhich shapes the cheese into the desired commercial package. Wrap in tin or aluminum foil and place in special flat boxes. The homogenization of milk for making cream cheese is not recom- mended. The addition of pimiento peppers at the rate of l.part of peppers to 10 or 20 parts of cream cheese greatly prolongs the keeping quality of the cheese. Keep the cheese ht a temperature of between 40° and 50° F. until consumed. ADDITIONAL COPIES OF THIS PUBLICATTON MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT 7RINTING OFFICE WASIUNGTON, D. C. AT 5 CENTS PER COP'S A PAT. MH. 21, 11 1 i mm^^ ^^ CONGRESS