THE STORY OF MILK TEXT

effervescent and may be regarded both as a food and a stimulant. It is sometimes prescribed by physicians in cases when the patient cannot retain other food. =Kefir= is a similar preparation originally made in the Caucasus by a fermentation started by Kefir grains which contain both yeast and various bacteria. The dry Kefir grains are soaked, first in lukewarm water, later in lukewarm milk, for several days, until they develop so much gas as to float on the top. A couple of tablespoonfuls of the grains are then added to a quart of milk which is left to ferment at 70° F. under frequent stirring or shaking. When the fermentation is fully developed the grains are strained off and the milk is bottled and kept for 1 to 2 days at 60°. The grains may be used at once again in fresh milk, and when the manufacture is finished they may be dried and kept, to be used again another time. [Illustration: Kefir grains of natural size; a, b and c dried; d, e and f soaked (Orla Jensen, Milk Bacteriology) ] ------------------------------------------------------------------------ CHAPTER III CHEESE [Illustration: Students making cheese in the University cheese factory, Madison, Wis. ] Most of the following pages on _Cheese_ were published in 1918 as a separate pamphlet to meet an urgent demand for brief directions along this line during the Food Conservation campaign. The copy has, however, been revised and new material has been added with the view of making this chapter more useful to those who desire to study in detail the manufacture of various fancy foreign types of cheese such as Edam, Swiss, Brick, Roquefort, etc., which are now made in this country in constantly increasing quantities. For more complete directions in cheese making students are referred to “A B C in Cheese Making” by J. H. Monrad, and other technical works. Cheese of a thousand different kinds is made, varying in properties and appearance from the solid, yet mellow and agreeable Cheddar cheese to the semi-soft, malodorous Limburger, the delicious, soft Neufchatel and Cream cheese, or the sweet Myseost of Norway. In India cheese was made centuries ago; to-day it is produced the world over, in the caves of the Swiss Alps and in the most modern and scientific American cheese factories and laboratories. Of these myriad types we can here describe only a few. Cheese may be classified into that made with rennet and that made without. Of cheese made with rennet some is what is called hard, some soft. The English and American _Cheddar_—the common _American cheese_—the _Dutch Gouda_ and _Edam_, the Swiss _Gruyere_, and the Italian _Parmesan_ are all hard cheese made with rennet. As examples of the soft varieties may be mentioned the French _Camembert_ and _Brie_, _Cream_ and _Neufchatel_ cheese. In a class by themselves are such cheeses as the French _Roquefort_, the English _Stilton_, and the Italian _Gorgonzola_, their peculiar flavors being derived from molds implanted in the curd. [Illustration] When cheese is made without rennet, the milk is allowed to curdle by natural acidity or it is in some other way made acid. Among the varieties made by this method the common _Cottage_ cheese is the best known. For many years imitations of foreign varieties such as Swiss and Limburger have been made in Northern New York and Wisconsin. As a result of the war and the cutting off of foreign cheese imports, the State of Wisconsin has built up a large business in these fancy varieties. New types have lately been added, as the _Romano_, _Riggiano_, and _Myzethra_, which are of Italian and Greek origin. Some of these are made of whole milk, some of partly-skimmed milk, and others of the albumin of the whey. Let us briefly review the characteristic features in the making of the older types. CHEDDAR CHEESE For a hundred years or more this famous cheese has been made and marketed at the village of Cheddar near Bristol, England. In the middle of the nineteenth century a farmer in that neighborhood, Joseph Harding of Marksbury Vale, systematized the manufacture and it was his method that became the model for cheesemaking in America. In this country it was first made in Herkimer County, N.Y., where Harry Burrell not only made cheese for the home market, but also exported to England, and his son, David H. Burrell, at Little Falls later developed the machinery which became the standard for the American and Canadian cheese factories. The factory system by which cheese was made from milk brought together from several farms, originated near Rome, N.Y., and soon cheesemaking became an important industry throughout Central and Northern New York whence it spread into Pennsylvania, Ohio and the West, as well as to Canada. To-day Wisconsin makes more cheese than all the other states together and Canada largely supplies England with Cheddar cheese of excellent quality. [Illustration: Joseph Harding, who systematized the making of Cheddar cheese in England ] [Illustration: David H. Burrell, who introduced laborsaving machinery and supplies in the cheese factories ] [Illustration: Jesse Williams, father of the American factory system ] _The Factory System_ The milk is delivered in the morning by the farmers at the factory and is weighed and strained through cheese-cloth into the cheese vat. When it is all in the vat it is warmed to a temperature of 86° F. by letting steam into the water surrounding the bottom and sides of the jacketed vat. [Illustration: A measuring glass and an accurate thermometer are indispensable ] [Illustration: The Marschall rennet test ] =Ripening.=—The milk should be slightly acid, not noticeably sour, yet sufficiently ripened for the proper fermentation to take place in the process that follows. The best cheesemakers regulate the ripening by adding a starter to the sweet milk and allowing the lactic acid bacteria to multiply in the milk until a _Rennet Test_[6] or _Acid Test_[7] shows that the desired degree of acidity has been reached. The starter may be sour whey or preferably prepared from sweet skim milk or whole milk with a commercial lactic acid culture as described in Chapter I under _Ferments_ and _Buttermilk_. From 1% to 2% starter is usually sufficient. An acidity of .18% to .20% or 2½ degrees on the Rennet Test is usually desired before the rennet is added. [Illustration: Christian D. A. Hansen, inventor of commercial rennet extract ] [Illustration: Blowing up the rennets to dry them ] =Adding Color and Rennet.=[8]—If the cheese is to be colored, from 1 to 2 ounces of liquid cheese color (Annatto dissolved in an alkali) per 1,000 lbs. of milk is now added and thoroughly mixed into the milk which is then set with rennet. Three ounces of a standard rennet extract to 1,000 lbs. of milk is usually sufficient. Enough should be used so that the milk will show beginning coagulation in 10 to 15 minutes and be ready to cut in 30 to 40 minutes. The extract should be diluted with ten times as much water and is then poured into the milk under vigorous stirring so as to be thoroughly distributed and incorporated in the whole mass. Owing to the scarcity of the raw material for rennet extract during the war, pepsin extracted from hogs’ stomachs has been substituted in many factories and is used either in dry form or as a liquid extract instead of rennet extract. With pepsin as the coagulant it is necessary to ripen the milk somewhat further than if rennet is used, in fact to the danger-point where a little more acidity is apt to do harm and produce a dry and crumbly cheese and loss of butter-fat in the whey. Most cheesemakers therefore prefer rennet when they can get it. The rennet having been added, the milk is left undisturbed until a firm curd has been formed. When the curd breaks or splits sharply before the finger pushed slowly through it, it is ready to be “cut.” [Illustration: Curd knives ] =Cutting.=—Two sets of curd knives are used, each consisting of a metal frame in which tinned steel blades are hung, in one vertically and in the other horizontally. The vertical knife is first carried slowly through the curd lengthwise and crosswise; the horizontal set of blades is then moved carefully through the length of the vat. When the cutting is over, the entire mass should be in cubes about half an inch square. The whey that begins to separate out should be clear and yellow. Milky whey is a sign that the butter-fat is escaping in it; the curd has been broken up too violently. In curdling, the casein encases the butter-fat and the object of the breaking up of the curd in the vat is to expel the whey but retain the fat in the cheese. =“Cooking” the Curd.=—Gentle heat is now applied to raise the temperature gradually to 98° or 100° in the course of about 30 minutes. Meanwhile the small pieces of curd are kept floating in the whey by gentle stirring with a rake and the hands, and are not allowed to pack at the bottom of the vat. The heating is easily regulated by opening the steam valve little by little. Through the “cooking” the pieces of curd shrink to some extent and are hardened so that they will gradually stand livelier stirring without losing butter-fat. After the cooking the curd is left for an hour or so in the whey for a slight acidity to develop and it is then shoved toward the sides of the vat and the whey is drained off. Here again the “Acid Test” may assist in determining when the whey should be drawn. [Illustration: Cutting the curd ] =Cheddaring or Matting.=—After thorough draining, the curd is packed together in the bottom of the vat or on a “sink” provided with a false bottom covered with cheese-cloth. After fermenting for 10 or 15 minutes it is cut into large pieces which are again packed together for further matting. The exact condition to be attained can be determined only by experience. [Illustration: “Cheddaring” or “Matting” the curd ] A simple test, the “Hot Iron Test,” may, however, help the cheesemaker to judge of this point. A handful of curd squeezed together and touched to a hot steam pipe or an iron rod heated almost red-hot in the fire under the boiler, and slowly withdrawn, will leave threads sticking to the iron. Depending upon the maturity of the curd, the threads will break at a length of from ½ to 2 inches. Usually fermentation is considered sufficient when threads 1½ inches long are formed by this test. [Illustration: Curd mill ] =Salting.=—The matting is then interrupted by breaking up and salting the curd. This can be done by hand or by a curd-mill which cuts or breaks up the curd and permits a thorough mixing in of the salt. Two or three pounds of salt to one hundred pounds of curd, or the curd from 1,000 lbs. of milk, is the usual ratio. =Pressing.=—Stirring and cooling the salted curd to about 80° F. makes it ready for packing into the hoops in which it is to be pressed. The hoop is usually a cylinder of heavy tin with a “follower” of wood on which the pressure is applied. Before the curd is put in, the hoop is lined with cheese-cloth which remains on the cheese, when it is taken out. The press mostly used in the factory is the continuous pressure “gang-press” in which a number of cheeses can be pressed at the same time. =Curing.=—After 18 hours’ pressure the cheese is taken out of the press and out of the hoop, weighed and placed on a shelf or table in the curing room. For the first week or ten days it is kept at a temperature of about 70°, later the cheese is removed to a cooler room and possibly placed in cold storage. Usually it is paraffined to prevent too much drying and cracking of the rind. [Illustration: Filling the curd into the hoops ] To cure a first-class Cheddar cheese takes from three to six months, but most of the American cheese is made to cure much more quickly and is eaten two to four months old. Indeed, it is generally shipped from the factory eight to ten days old and whatever further curing it gets is in the warehouse of the commissionman or in the grocery store. [Illustration: The Gang press ] =Form, Size and Packing.=—The old style American cheese is cylindrical, about 14 inches in diameter, and varying in depth to weigh between 60 and 80 pounds. Various other forms are now often made, square and long or in fancy shapes, such as a ball or a pineapple. Aside from such freaks, which have never become very popular, other deviations from the large, standard, American Cheddar, are also made to a considerable extent. People who have visited the beautiful National Dairy Shows held in turn in Chicago, Springfield, Mass., and Columbus, O., the National Milk and Dairy Farm Expositions of New York City, the Ontario Provincial Fair held each year at Toronto, or the annual State Fairs in New York, Wisconsin, Michigan and other cheesemaking sections will have in mind first the prominent exhibits of the regular Cheddar, showing a uniformity in texture, form and taste that is really remarkable. But one will also admire the variety of other forms. There are the _Flats_ or _Twins_, packed two in a box and weighing together the same as one _American_; the _Young Americas_ packed four in a box; the _Longhorns_ of six to eight inches in diameter; others made like a loaf of bread and creased so that a pound or two may be cut off fairly accurately, etc. [Illustration: Taking the cheese out of the press ] The _Giant Cheeses_, weighing five to six tons, occasionally exhibited and cut up at World Fairs and on similar occasions are, like the pineapple cheese, a curiosity rather than an industrial product. One of the best forms, in the writer’s opinion, is the small 5-lb. cheese, proportioned exactly like the large American. This makes a suitable size for an average family, the members of which have learned to appreciate a good cheese. If it is made smaller, too much is lost in the rind; if larger it gets too old before it can be consumed by one family. [Illustration: Curing room ] The larger cheeses are usually packed in neat, snug-fitting elm-wood boxes, with thin “Scale Boards” on the top and bottom of the cheese, the smaller ones in paraffined pressed pulp or pasteboard boxes. =Cleaning the Vats and Utensils.=—Like every other place where milk and its products are handled, the cheese factory must be kept scrupulously clean. Vats and utensils should be rinsed first with cold or lukewarm water or whey, then scrubbed with boiling hot water and if necessary with soda, soap, or washing powder. The surroundings should be kept neat and attractive, and the cheesemaker must see that the transportation cans are kept clean by the farmers and the milk delivered in good condition. [Illustration: Cheese box ] =Yield.=—The yield is around 10% of the milk. To make a pound of fresh cheese takes from nine to eleven pounds of milk. In curing, a part of the weight is lost by evaporation, but this loss is reduced to a minimum by paraffining. In some localities an increased yield is obtained by washing the curd and making it absorb all the water it can hold. The process is not commendable and while it may sell to some extent, in certain markets where a soft, fresh cheese is liked, “washed” or “soaked” curd cheese can never compare favorably in quality with a well-made, firm Cheddar cheese that is mellowed down by long-time curing to a consistency so it will fairly melt in your mouth. =Composition.=—The American cheese contains almost all the casein and the butter-fat of the milk, besides such portions of the milk-albumin, milk-sugar, and mineral matter as are held in the water or whey which is retained in the cheese. In round figures average American cheese contains equal parts of casein, butter-fat and water, 30 to 35% of each. In order to protect the honest maker and the consumer and prevent “soaking” of the curd to an extent that may be considered fraudulent, the dairy laws of the State of New York limit the contents of water permissible to 40% and 42% respectively for certain classes of cheese. =Qualities.=—A good Cheddar cheese should be mellow, yet solid, without holes, and of an agreeable taste, neither sharp nor bitter. Cheese can be made of skim milk, but it is hardly palatable. In the fall of the year, when the average milk is rich in butter-fat, 1% or 2% butter-fat may be taken from the milk and the resulting partly-skimmed milk will still make a fairly good cheese, hardly distinguishable from full cream cheese. Under the laws of the State of New York it must, however, be marked “Skim Milk Cheese.” Cheese Made from Pasteurized Milk From time to time attempts have been made to make Cheddar cheese from pasteurized milk. If the milk is heated to 145° only, and held for 30 minutes at such temperature, its property to form a firm curd with rennet is not destroyed and it will make a fine cheese, but if it is pasteurized at a higher temperature it will not curdle firmly until it is ripened or otherwise brought back to the condition required for satisfactory action of the rennet ferment. Thorough ripening with a pure culture starter will do it, or an addition of muriatic acid will accomplish the same in a shorter time, but care must be taken not to use too much, which would make the cheese dry and crumbly. Dr. J. L. Sammis and A. T. Bruhn of the Wisconsin Dairy School worked out the problem and systematized a process which is described in Bulletin 165 of the U. S. Department of Agriculture and by which it is claimed a first-class cheese can be made regularly from thoroughly pasteurized milk. Making Cheddar Cheese on the Farm [Illustration: American outfit for farm cheese making ] [Illustration: Plain wooden vat and curd mill ] It takes quite a little experience to make a good Cheddar cheese and, unless one has the time and opportunity to study it and make it an every-day practice, it is not as a rule advisable to attempt making Cheddar cheese in the home from the milk of one or a few cows. The amateur will usually find it easier to make Neufchatel or Cream or Cottage cheese for home use or for the home market. [Illustration: Danish kettle and cheese vat ] If Cheddar cheese is to be made regularly it is best to get an outfit consisting of a small boiler and a jacketed vat, although cheese may be made in a plain wooden tub or any other convenient vessel. The double bottomed vat generally used in American as well as in Danish dairies facilitates both the heating of the milk before setting and the “cooking” of the curd in the whey after cutting. Either low pressure steam, or—better—water heated by steam, is introduced in the space between the outer, wooden bottom and the inner, tinned steel or copper bottom. If it is cool the milk should be warmed to 86° F. In the summer it may be warm enough as it comes in, fresh from the cow. If not, heat it by steam or by setting it in a “shot-gun” can in another vessel of hot water, stirring frequently, until the thermometer shows 86°. It may be well to add a little buttermilk or sour whey from the preceding day, or a pure culture starter made with Buttermilk Tablets, not to exceed 1% or 2%. [Illustration: Cutting the curd ] If it is desired to make colored cheese add a teaspoonful of liquid cheese color, or ½ cheese color tablet dissolved in warm water, to 100 pounds of milk, more or less according to season and the shade of color desired in the cheese. Next add the rennet. Where cheese is made from less than 500 lbs. of milk Rennet Tablets are handy, one tablet to 80 or 100 lbs. For less than 50 lbs. of milk, Junket Tablets may be used, one to a gallon. Dissolve the tablet, or tablets, or fraction of a tablet, as the case may be, in _cold_ water and stir the solution well into the milk, making