THE STORY OF MILK TEXT

flavor. After eight or ten weeks the cheese is packed in paper and tinfoil and is ready for the market. =Brick= cheese is something between a Cheddar and a Limburger, of a milder flavor than either, not as hard as the former but firmer than the latter. The milk is slightly ripened and is set with rennet at 86° so as to coagulate in 20 minutes. The curd is “cooked” to 110° or more and is not allowed to “mat” as for Cheddar cheese, but is dipped out of the vat before much acidity has developed, into the molds, which are rectangular boxes without top or bottom placed on a draining table where the whey runs off. The mold is usually 5 inches wide, 8 inches deep and 10 inches long. When it is filled with curd a follower is put on the top and a slight weight, a couple of bricks, on the follower. The cheese is turned a few times and the next day it is taken out of the mold and placed on the salting table. The salting is done by rubbing the cheese on all sides with salt which penetrates the curd and draws out moisture. This is repeated for 3 days and the cheese is then left to cure, being washed and wiped off every week to prevent molding. Brick cheese is shipped one or two months old. It is wrapped in paper and packed twenty in a box. =Munster Cheese= is very much the same as Brick except for the form, it being round, molded in a perforated tin hoop instead of the box used for Limburger and Brick. SOFT RENNET CHEESE The soft cheese made with rennet may be classified as _fresh_ and _cured_. =Neufchatel.=—The fresh soft cheese of the _Neufchatel_ or _Cream Cheese_ type is easily made and may be produced in any house from a small quantity of milk. The milk is set at a comparatively low temperature, usually 72° F., with very little rennet, just enough to coagulate the milk in about eighteen hours. During that time a slight acidity develops in the milk. When it is firmly curdled it is carefully dipped on to cheese-cloth suspended on a frame, or into cotton bags where it drains overnight. To make the cheese quickly a starter is sometimes used and more rennet employed. The milk is heated to 80° F., 25% starter and 7½ c.c. of rennet extract, or one rennet tablet per hundred pounds of milk, are added and the milk curdles in about 30 minutes. After draining for a few hours the curd is gently pressed for a similar time. When the whey is fairly well expelled, the curd is kneaded or run through a meat cutter with a little salt, not more than 2½ oz. to 10 lbs. of curd. The outfit and the manipulation is essentially the same as described under Cottage cheese. A superior quality is obtained by pasteurizing the milk and if that is done a pure culture starter should always be used. If the slow setting method is used a very small amount of starter, say ½%, is sufficient, but when the quick process is employed 10% to 25% may be added. [Illustration: Molding Neufchatel cheese ] To give it a good appearance for market, the cheese is molded in little tin molds very much like a quarter-pound baking powder can with open ends. The cylindrical roll of cheese is wrapped in parchment paper and tinfoil and is immediately ready for consumption. In an ice box it will keep for a week or so. Neufchatel cheese may be made from whole milk or partly-skimmed milk. The yield is from 10 to 20 lbs. out of 100 lbs. of milk. =Cream Cheese= is usually made in the same way. A mixture of cream and milk containing about 10% butter-fat is used, though sometimes the cream is not added until the time of salting. The mold is square, 2½” × 1½” × 2” deep. These soft kinds of cheese are often mixed with chopped peppers, olives or nuts and make excellent sandwiches. =Cured Soft Cheese.=—For _Cream_ or _Neufchatel_ cheese, made for curing, the curd is salted more than for fresh cheese, or the molded cheese is rolled in salt. For a week or two it is placed in a curing room on straw mats or the like where it ferments slightly before being wrapped and packed for shipment. =French Soft Cheese.=—The many forms of French soft cheese as represented by the _Brie_, the _Camembert_, etc., are subjected to special fermentations which give to each its peculiar flavor. Attempts have been made to use pure cultures of the bacteria active in such fermentations and so reduce the art of cheesemaking to a more scientific process. But it has been found that any desired kind of cheese cannot be made simply by adding a culture of this or that bacterium to pasteurized milk. Of vastly greater importance for the development of the proper bacteria and flavor is the handling of the milk and the curd by the experienced cheesemaker. Inoculation with a pure culture alone does not make the special cheese wanted. CHEESE MADE WITHOUT RENNET [Illustration: Mono-service jar ] =Cottage Cheese.=—Of the sour milk types the common _Cottage Cheese_ is the best known. It is made from skim milk which in a warm room will curdle when sour, whether rennet and a starter are used or not. The thick sour milk is heated to anywhere between 100° and 120° and dipped into bags of cheese-cloth hung up for draining. The next day light pressure is applied for 12 to 24 hours, when the curd is kneaded, slightly salted, formed into balls and wrapped in parchment paper or packed into jars. For this purpose paraffined paper jars are very practical. The more the curd is heated in the whey the drier will be the cheese. Often it is improved by allowing the curd to become rather dry and then working new milk or a little cream into it, according to the use to which it is to be put—whether it is for bakers’ stock or for the table. Simple directions for making Cottage cheese are given in Farmers’ Bulletin 850 and A. I. 17, issued by the United States Department of Agriculture from which we reprint the following and copy the accompanying illustrations: [Illustration: Pouring the curdled milk on cloth to drain ] “One gallon of skim milk will make about 1½ pounds of cheese. If the milk is sweet it should be placed in a pan and allowed to remain in a clean warm place at a temperature of about 75° F., until it clabbers. The clabbered milk should have a clean, sour flavor. Ordinarily this will take about 30 hours, but when it is desirable to hasten the process a small quantity of clean-flavored sour milk may be mixed with the sweet milk. “As soon as the milk has thickened or firmly clabbered it should be cut into pieces 2 inches square, after which the curd should be stirred thoroughly with a spoon. Place the pan of broken curd in a vessel of hot water so as to raise the temperature to 100° F. Cook at that temperature for about 30 minutes, during which time stir gently with a spoon for 1 minute at 5-minute intervals. [Illustration: Lifting the cloth back and forth to facilitate draining ] “At the conclusion of the heating, pour the curd and whey into a small cheese-cloth bag (a clean salt bag will do nicely) and hang the bag in a fruit-strainer rack to drain, or the curd may be poured into a colander or a strainer over which a piece of cheese-cloth has been laid. After 5 or 10 minutes work the curd toward the center with a spoon. Raising and lowering the ends of the cloth helps to make the whey drain faster. To complete the draining tie the end of the bag together and hang it up. Since there is some danger that the curd will become too dry, draining should stop when the whey ceases to flow in a steady stream. [Illustration: Pressing the curd ] “The curd is then emptied from the bag and worked with a spoon or a butter paddle until it becomes fine in grain, smooth, and of the consistency of mashed potatoes. Sour or sweet cream may be added to increase the smoothness and palatability and improve the flavor. Then the cheese is salted according to taste, about one teaspoonful to a pound of curd. “Because of the ease with which the cheese can be made it is desirable to make it often so that it may be eaten fresh, although if it is kept cold it will not spoil for several days. If the cheese is not to be eaten promptly it should be stored in an earthenware or glass vessel rather than in one of tin or wood, and kept in a cold place.” [Illustration: Apparatus needed in making cottage cheese ] =Making Cottage Cheese with Rennet.=—In the bulletin mentioned a method is also given for making the cheese with rennet or pepsin. Junket Tablets make a convenient form of rennet to be used for this purpose. The advantages claimed for this method are: 1. A finer textured and more uniform cheese. 2. The making requires less time and attention. 3. Losses of fat in the whey are reduced. The process is the same as described above except that a solution of _Junket Tablets_ is added to the milk at the rate of one tablet to 100 lbs. of milk. For less milk use a fraction of a tablet, or dissolve one tablet in ten tablespoonfuls of water and use one spoonful of the solution for each 10 lbs. of milk. If a starter is used the rennet solution is added immediately after the starter is put in; if no starter is used the milk is left for five or six hours at 80° F. to ripen before adding the rennet. The milk will curdle overnight. After draining for thirty minutes on cotton sheeting the ends of the cloth are tied together and a weight is placed on top to press the curd gently until the desired consistency is attained. Salt may be worked in at the rate of 2½ ounces to 10 lbs. of curd. If desired, add sweet or sour cream at the rate of ½ pint to 10 lbs. of curd or ¼ pint of cream to the product from 30 lbs. of milk. It will be seen that Cottage cheese made with rennet is really the same as Neufchatel cheese, the only difference being in the form and packing or wrapping of the finished cheese. =Snappy Cheese.=—By allowing the sour skim milk curd to ferment under careful regulation, a variety of sharp, snappy, more or less hard cheese can be made. Though there is no general demand for them, some kinds are quite popular in their own restricted localities. The Danish _Appetite cheese_ is only one of the many varieties which have as many names. =Club Cheese= and similar varieties are made by grinding up old dry cheese with a little butter and packing the product in jars or other attractive packages. American, Roquefort, or any other well-known type may be used as the stock for these cheeses. Everywhere they are favorites in dining cars and lunch rooms. [Illustration: Milking the goat in Norway ] =Whey Cheese.=—In Switzerland the so-called _Zieger cheese_ is made from sour whey, the albumin being coagulated by heat and, with whatever butter-fat there may be left in the whey, skimmed off the top. In Norway _Myseost_ (“Ost” is Norwegian for cheese) is made by boiling down whey almost to dryness. If goat milk is available to mix in, it improves the cheese. The main substance is sugar of milk and the cheese has a sweet, syrupy flavor. MILK SUGAR The by-product, sugar of milk, is produced by acidifying the whey, heating to boiling and neutralizing with lime until the albumin is coagulated. It is then filtered out and the clarified liquid is concentrated in vacuum. From the thick syrup the sugar is allowed to crystallize out, leaving the salts or mineral matters (milk-ash) in the remaining liquid. The use of milk-sugar is limited to medicinal purposes and for modifying milk for infants. The production is therefore not very extensive. CASEIN In a number of creameries casein is produced from skim milk by precipitating it with an acid and drying and pulverizing the precipitate. Casein is widely used as a substitute for ivory, in billiard balls, buttons, etc. It is also used as glue, and as a binder in paints. MILK POWDER The production and use of dry milk has increased enormously during the last few years and the processes of manufacture have been improved well-nigh to perfection. There are several methods practiced, the most important being the following: The _Just-Hatmaker_, in which a large metal drum or cylinder revolves slowly in a tank of milk. The drum is heated by steam inside and, as it rolls out of the milk, the metal surface picks up a thin film of milk which quickly dries and is removed by a scraper. The _Eckenberg_ process employs vacuum evaporating pans, like those used for making condensed milk and maple syrup. The _Merrell-Soule_ Company’s method consists in driving a blast of hot air into a fine spray of milk, which at once reduces the milk to a fine powder. In the “_Economic_” process the milk is dried by hot air the same as in the Merrell-Soule method, but in dropping through a tower from a height of some 30 feet the milk meets several blasts of air of different temperatures. It is claimed that in this way alone rich milk and cream may be reduced to a powder without injury to, or change of, the original fat globules. =Skim Milk Powder.=—Beautiful skim milk powders are now made which dissolve perfectly in water. Containing, as they do, the extremely nourishing constituents of the fatless milk in a most palatable form, they can be used in baking and in many food products to great advantage. =Whole Milk Powder.=—Until recently dried whole milk was not produced of good keeping quality as the butter-fat had a tendency to become rancid before many months. But improvements are constantly being made and milk powders of every degree of richness bid fair to take the place of fresh milk on board ships and in other places where milk must be kept a long time before being used. In many new food preparations of value, milk powder is filling a long-felt want. Dissolved in 8 or 9 times as much water, milk powder makes a liquid almost identical with pasteurized fresh milk. It has already been mentioned under the chapter on “Cream” and under “Ice Cream” how skim milk powder and unsalted butter, _emulsified_ in a suitable amount of water or milk, make an excellent material for ice cream. CONDENSED AND EVAPORATED MILK Milk cannot be boiled down in a common open kettle or steam boiler without being scorched. Evaporating or condensing is therefore usually done in a vacuum pan at a low temperature. Condensed to one-third of its volume and excluded from the air by canning, milk will keep well for months, and has many uses as a substitute for fresh milk. Often sugar is added as a preservative, and where sugar would be added anyway, as in coffee, ice cream, etc., this is unobjectionable. For purposes where sugar is not wanted, unsweetened condensed or evaporated milk is on the market, so carefully made that the taste of the original milk is hardly changed at all by the process. When water is added in the proportion of two parts of water to one of the evaporated milk, the fluid obtained excels even that from milk powder in its resemblance to fresh milk. WHEY Whey is a by-product in cheesemaking. Usually it is fed to hogs and especially together with grain or bran it makes an excellent food for them. But whey is also prepared for human food. In the hospital or in the home it serves as a substitute for milk when a mild diet of easily digested food is temporarily required for a weak stomach. For such purposes it must not be allowed to become acid as in cheesemaking, but should be prepared as the chief product from sweet new milk or freshly separated skim milk. The sweet milk is set with rennet—one Junket Tablet, dissolved in cold water, to a quart of milk—at a temperature of 90° to 100° F. As soon as a firm curd is formed it is carefully broken up and transferred to a strainer of cheese-cloth. Unless it is to be used at once, the whey strained off should be immediately cooled to 50° or lower. If left at a higher temperature it will soon become sour. A teaspoonful of limewater to a quart, or a pinch of soda, will help to keep it sweet. Still, in any event, it should not be kept long, but prepared fresh when required. ------------------------------------------------------------------------ CHAPTER IV MILK AS A FOOD Milk is first of all the food for the young,—until a certain age the only food, and a perfect food. It contains but little refuse or waste and is under favorable conditions almost wholly digestible. NUTRIENTS All foods contain certain groups of nutrients which may be classified according to various functions in nutrition and their chemical composition. =Protein.=—The protein group of nutrients contains nitrogen and is necessary for building up the tissues of the body, the muscles and the tendons which also contain nitrogen. Only by this group can tissues wasted by constant wear and tear be rebuilt. Proteins are the flesh-forming group. To some degree the proteins or albuminoids are also active in producing fat in the body, but the other groups of nutrients, especially the fats, also contribute. =Fats and Carbohydrates.=—Another important function of food is to produce and maintain the animal heat. The main sources of this necessity are the fats and the carbohydrates, so called because they consist of the element carbon combined with oxygen and hydrogen, the last two in the exact proportion in which they are combined in water. All of these three groups furnish the fuel, so to speak, for the body, but they are not equal in this respect. Pound for pound, when burned in the body, the fats yield 2¼ times as much heat as protein or the carbohydrates. =Mineral Matters.=—Finally there are in all foods the mineral matters, a group containing a number of salts which are indispensable because they are constituents of every part of the body. Phosphate of lime, for instance, makes up one-half of the substance of the bones, and the sulphates and chlorides of potash and soda, iron, etc., are everywhere present in smaller quantities. No food in which any of them is lacking is complete. =Relation.=—The value of a food depends largely upon the relation of one group of nutrients to another. Proper nutrition can only be obtained when a sufficient amount of flesh-forming as well as of heat-producing nutrients are present, when the “nutritive ratio” is properly balanced for the particular purpose in view, be it the growth of the child, the maintenance of the body, the restoration of matter consumed by labor of body or brain, or the supply of heat to make up for cold surroundings. =Milk contains all= of these groups of nutrients. The protein is represented in milk by the casein and albumin, the fats by the butter-fat, the carbohydrates by milk-sugar, and the mineral matters by the milk-ash. Human milk contains them in a perfect proportion for infants, and for all purposes of nutrition cow’s milk may be used to make up a “balanced ration,” if not alone, then in connection with other food. =Nutritive Ratio.=—As we said before, the “nutritive ratio” of a food means the ratio of its flesh-forming constituents—proteins—to its heat-producing nutrients—carbohydrates and fats. Cow’s milk, containing 3.25% protein, 4% fat and 5% milk-sugar, has a nutritive ratio of 1 : 4.3, i. e., 1 part of protein to 4.3 parts of heat-giving nutrients, counting the fat equal to 2¼ of carbohydrates (multiplying the 4% fat by 2¼ makes 9, added to the 5% of sugar, makes 14; 3.25 to 14 equals 1 to 4.3). Skim milk, containing 3.4% protein, 0.2% fat, and 5.1% sugar, has a ratio of 1 : 1.6 (3.4 : 5.45). Mother’s milk, containing 2% protein, 4% fat, and 6.5% carbohydrates, has a ratio of 1 : 7.75. To substitute cow’s milk for mother’s, it must therefore be “modified.” =Calories.=—Another way of comparing various foods than by the nutritive ratio is by measuring their “fuel value” or energy-producing capacity.