Thursday, December 26, 2013

The Process of Making Swiss Cheese

The milk is delivered twice a day without cooling. It usually reaches the factory at a temperature of 92° to 96° F. It is strained into the kettle, and starter and rennet added at the same temperature as received. Enough rennet should be used to give a coagulation ready for cutting in twenty to thirty minutes.

The firmness of the curd is tested by inserting the index finger in an oblique position, then raising it slightly and with the thumb of the same hand starting the curd to break or crack. When the curd is coagulated ready for cutting, it will give a clear break over the finger.

It is important to keep the temperature uniform while coagulation is in process, and this is best accomplished by the use of a little pan arrangement which fits into the top of the kettle. When this is full of water at 100° F., the temperature of the air above the milk will be about 90° F. When the curd is ready for cutting, a scoop may be used and the top layer carefully turned under to equalize the temperature more closely.

Cutting the curd.—In some cheese factories, knives resembling Cheddar cheese knives are employed to cut the curd. In other factories, a "Swiss harp" is used to break the curd. The curd is usually cut or broken into pieces about the size of kernels of corn. The practice of "breaking" curd instead of cutting it with sharp curd-knives produces excessive loss at times.

Experimental study has shown that the loss of fat may be kept as low as 0.3 per cent if modern curd-knives are substituted for the breaking tool formerly used. Study of Swiss cheeses of all grades supports the opinion that the removal of a small part of fat from usual grades of factory milk produces a better quality of product than the use of rich whole milk. This may be accomplished through the escape of fat in the whey on account of breaking the curd and stirring it vigorously, or by skimming a part of the milk which is then curdled, cut and stirred under such conditions as to minimize the loss of fat.

Cooking the curd.—After cutting, the curd is stirred in the whey for about twenty minutes before the steam is turned on and is then heated to 128° to 135° F. While this heating is in progress, constant stirring must be given to avoid matting. This excessive stirring breaks the curd up into pieces about the size of wheat kernels, and accounts for the large fat loss, which is one of the main sources of loss in making Swiss cheese. This stirring is accomplished by a rotary motion, and the use of a brake, which is a piece of wood closely fitting the side of the kettle. This creates an eddy in the current at that point and gives a more uniform distribution of temperature.

The process of cooking takes from thirty to forty minutes, and at the end of that time the degree of toughness may be determined by making a roll of curd in the hand, and noticing the break when it is given a quick flip. A short sharp break indicates the desired toughness.

Draining and hooping.—In this process, the cheese-makers' skill is displayed. With the hoop prepared, and the curd at the correct stage of toughness, the operator takes a press cloth, wets it in whey, slips it over a flexible iron ring which can be made to fit the shape of the kettle, gives the contents of the kettle a few swift revolutions, then suddenly reverses the motion, with the result that the contents form into a cone, and the ring and bandage are dexterously slipped under this cone, and drawn up to the surface of the whey with a rope or chain and pulley.

This part of the process is the most important, as a cheese must have a smooth firm rind, else it will quickly crack. With too large a batch of milk, the curd can be cut into two pieces and hooped separately. With the mass of curd at the top of the whey, the piece of perforated iron plate just the size of the hoop is slipped under the mass, and attached to the pulley by four chains. Then the top of the mass is carefully leveled off, because while still in the whey, it cannot mat badly and so tend to develop a rind crack.

Now the mass is raised clear of the whey, and run along a short track to the drain table, where it is put in the press.

Pressing.—The mass of curd is dropped into the hoop, the edges of the cloth carefully folded under, and the cloth laid on top, then the pressure is applied, gradually at first, but increasing until the final pressure is about fifteen to twenty pounds to a pound of cheese.
During the first few hours the cloths must be changed frequently, and the cheese carefully turned over each time, to secure a more uniform rind. After a time the changes are less frequent, and at the end of twenty-four hours the cheese is taken to the salting-room.

Salting may be done by either the brine or dry method. To prepare a brine bath, add salt to a tank of water until it will float an egg, and add a pailful or more of salt every few days thereafter to keep up the strength. The cheese is then placed in this bath and left for three to five days, depending on the saltiness desired. As the cheese floats with a little of the rind above the surface, it should be turned a few times to insure uniformity of salting. With dry salting, the salt is rubbed on the cheese by hand or with a stiff brush, and any excess carefully wiped off, leaving only a slight sprinkle on the surface to work into the cheese.

Thursday, December 12, 2013

Swiss Cheese's Clean, Unacidic, Unfat Milk

Swiss cheese requires clean sweet milk. Dirt, high acid and infections with undesirable bacteria involve difficulties of manufacture and frequent losses of cheese.

One common practice rejects milk if it shows acidity above 0.15 per cent. To secure milk in this condition, factories are small and located so close to the producing farms as to secure 1000 to 3000 pounds of milk delivered warm from the cow twice a day. The cheese is made twice daily from this fresh milk. If, however, milk is properly cared for, it is possible to mix night's and morning's milk without bad results. In fact, in working experimentally with high grade milk and taking precautions against loss of fat, it has been necessary to skim (separate) part of the milk, thus reducing the ratio of fat to casein.

Analysis of good Swiss cheeses shows that the desired texture is more uniformly obtained with milk in which the fat is less than the normal ratio. This assumes that the manufacturing loss is kept down so that the fat removed offsets the extra loss from curd-breaking.

Thursday, November 28, 2013

What is a Swiss Cheese Kettle?

Swiss-cheese kettle.
Swiss Cheese Kettle
Swiss cheese cannot be made in a vat like other types. In place of the vat is used a kettle, generally of copper, and it may or may not be jacketed for steam or for hot water.

These kettles vary in capacity from 600 to 3000 pounds of milk.

The cheese-maker takes the best care possible of his kettle, for an unclean utensil is one of the easiest sources of contamination of the milk. When the kettle is not jacketed, and it is only in recent years that this has been done, it is suspended in a fireplace by means of a crane arrangement.

This fireplace uses wood, and is built of brick or stone, so that the kettle rests on the edge and is provided with a door which swings upon another crane, and can be closed while the fire is going. When the kettle is swung on a crane, it is possible to swing it under the weigh-stand for filling. This requires a lid to swing down over the fire, and keep the room free from smoke. The chimney generally has a rather high stack to secure a good draft. This kettle is fastened to the crane by a large iron band passing around the neck, to which a bail or handle is attached. The kettle may be raised or lowered by means of a simple screw on this beam. The crane consists of a heavy beam working in sockets in the floor and a beam or cross brace, which has another and shorter beam braced to it, to take the weight of the kettle.

The weigh-stand, and its efficient location, is a matter of extreme importance. It is elevated a little above the remainder of the floor to allow gravity to do the work. The next most important equipment is the press and draining table. The table is made of wood or stone, and has a slight slope to allow the whey to drain off. The press is generally a jack screw which, braced against a beam, will exert an enormous pressure on the table below.

Swiss cheeses are made in two styles, the "round" or drum and the "block" or rectangular forms, each of which has its advantages. For the round style, which is most commonly made, the forms for hooping are of metal or of elm wood, and consist of strips of a given width, generally six inches, but of an undetermined length. These strips are then made into a circle and held by a cord, which is easily lengthened or shortened, thus varying the diameter of the hoop.

Besides these hoops, cheese boards or followers are needed. These are heavy circular boards, of a size to fit that of the cheese generally made, and are banded with iron around the edge and cross-braced on the bottom for rigidity. The small tools of the factory consist of knives to cut the curd, and of a "Swiss harp" or other similar tool to stir the curd. Many clean bandages are also needed, and a kettle brake.

Thursday, June 13, 2013

Pennsylvania pot cheese

A form of "pot" cheese is made in certain counties of Pennsylvania, principally for local use. Production of this cheese on a factory basis is now being attempted (Editor's note: in 1918!). The steps in manufacture are about as follows:

(1) The home-made type of cottage cheese curd is prepared, put into a crock or pot and covered carefully;

(2) kept in a warm place (in kitchen usually);

(3) stirred from time to time, until it has ripened to a semi-liquid condition. This occurs very rapidly under the attack of Oidium lactis accompanied by bacteria. Within a period of three to seven days, according to the temperature and to the water-content of the mass, the granules of curd become covered with a wrinkled gelatinous almost viscid mass of mold mycelium beneath which is a layer of semi-liquid curd with a strong characteristic odor and taste. This ripened or semi-liquid part reaches about half the total mass in four or five days at favorable temperatures.

(4) The vessel is then placed in a larger vessel of water and heated over the fire with constant stirring until the whole mass is melted and smooth.

(5) Butter or cream, and salt or other flavor is finally added, stirred in and the liquid cheese poured into molds or jelly glasses to cool. If properly made and cooked, the resultant cheese has a soft buttery consistency with an agreeable flavor, which frequently resembles that of Camembert cheese.

Monday, February 11, 2013

The Digestibility of Cheese

From "The Book of Cheese", 1918.

Although it has been a staple food with many races for uncounted years, there is a widespread belief that cheese is suitable for use chiefly in small quantities as an accessory to the diet, and that in large quantities it is likely to produce physiological disturbances. The question of digestibility was made the subject of a special investigation by the United States Department of Agriculture.

Calorimeter experiments were made to test the digestibility of several varieties of cheese and some of these varieties at various stages of ripening. All forms of cheese were found to be digested as completely as most of the usual forms of food. Approximately 90 per cent of the nitrogenous portion (casein) was retained in the body. Unripe cheese in these experiments was apparently digested as completely as the ripened forms.

These experiments make clear the possibility of making cheese a more prominent article in the regular dietary than is usual in America. They especially point to the desirability of the use of the skim and partially skim cheeses, which as cheap sources of protein when properly combined with other foods, may be made to replace meats as a less costly source of proteins.

Cheese is then to be classed with meat and eggs, not with condiments. An ounce of Cheddar cheese roughly is equivalent to one egg, to a glass of milk, or to two ounces of meat. It is properly to be combined with bread, potatoes and other starchy foods, lacking in the fat in which the cheese is rich.

These experiments included Roquefort, fresh-made and ripe Cheddar, Swiss, Camembert and Cottage cheese.

Sunday, February 10, 2013

French Camembert

The soft cheeses ripened by molds are French in origin. Their manufacture has spread into Germany, Italy and America. Of the series, the most widely known is Camembert, which will be described as typical for the group. Brie, Coulommiers, Robbiola and Ripened Neufchâtel belong to this series.

The origin of Camembert is given by French authorities as 1791 in the Commune of Camembert near Vimoutiers in Orne, France. From a very restricted production at first, Camembert-making has spread through the region from Caen in the west to Havre, Rouen and a considerable area east of Paris.

In America Camembert began to be made in one factory about 1900. Several other factories followed by 1906. The difficulties and losses encountered led to the abandonment of these undertakings, until at the outbreak of the European war in 1914 but one factory was making Camembert and that only on an experimental scale. Meanwhile the United States Department of Agriculture and the Storrs Experiment Station had taken up and solved, on an experimental basis, most of the problems arising in these commercial failures. A shortage of product at the outbreak of the war brought about the re-establishment of a series of factories. The product as put on the market indicates that a permanent establishment of Camembert-making is entirely practicable.

Camembert cheese is made from cow's milk either whole or very slightly skimmed; the removal of about 0.5 per cent of fat has been found to be desirable if not actually necessary.

These cheeses are made in sizes 2½ to 4½ inches in diameter and 1¼ to 1½ inches in thickness. They are ripened by the agency of molds and bacteria which form a felt-like rind over their whole surface, ⅟16 to ⅛ of an inch in thickness. This rind may be dry and gray or grayish-green, consisting of a felt-like surface of mold on the outside, below which a harder portion consists of mold embedded in partially dried cheese, or the moldy part may be more or less completely overgrown or displaced by yellowish or reddish slime composed mainly of bacteria. Good cheeses may have either appearance.

Inside the rind, the cheese is softened progressively from the rind toward the center from all sides, so that a fully ripe cheese has no hard sour curd in the center, but is completely softened. No mold should be visible inside the rind, but the moldy rind itself is necessary because the ripening is caused by the enzymes secreted by the organisms of the rind into the cheese. As the curd ripens, the changed portion assumes a slightly deeper color than the unripe curd as a result of chemical changes.

Well-ripened cheeses vary from nearly a fluid texture to the consistency of moderately soft butter. The ripening of Camembert is finished in wooden boxes which protect the cheeses from breaking after they become soft and during the market period.

Saturday, February 9, 2013

The Water Content of Different Cheeses

From "The Book of Cheese", 1918.

In this table the series of typical dairy products are first arranged according to water-content of the final product. Approximate limits of percentages of milk-fat are also given, because milk-fat frequently affects texture to a degree almost equal to water. Column 4 gives the period within which the more quickly perishable cheeses are usable, and the length of the ripening for the more solid forms. The correlation between water-content, texture and the time of keeping is clearly shown for most varieties.

Variety Per

  Cottage 70 trace a few days Bacteria
  Skim Neufchâtel 70 trace a few days Bacteria
  Neufchâtel 50-60 12-28 a few days Bacteria
  Camembert 50 22-30 3-5 weeks Molds
  Cream cheese 40-50 35-45 a few days Primarily
  Limburger 40-45 24-30 3-6 months Bacteria
  Roquefort 38-40 31-34 3-6 months Mold
  Brick 37-42 31-35 3-6 months Bacteria
  Cheddar 30-39 32-36 6-12 months Bacteria
  Swiss 31-34 28-31 9-18 months Bacteria
and yeasts
  Parmesan 30-33 2-3 years Bacteria

The soft cheeses are quickly perishable products. Bacteria and molds find favorable conditions for growth in products with 45 to 75 per cent of water. If such growth is permitted, enzymic activities follow quickly with resultant changes in appearance, texture, odor and taste. Refrigeration is necessary to transport such cheeses to the consumer, if properly ripened. Trade in these forms may continue throughout the year in cool climates and in places where adequate refrigeration is available. Practically, however, outside the large cities this trade in America is at present limited to the cold months; inside the large cities much reduced quantities of these cheeses continue to be handled through the year.

In the stricter sense, the soft group of cheeses falls naturally into two series: (1) the varieties eaten fresh; and (2) the ripened soft cheeses. Those eaten fresh have a making process which commonly involves the development of a lactic acid flavor by souring, but no ripening is contemplated after the product leaves the maker's hands. In the ripened series, after the making process is completed, the essential flavors and textures are developed by the activity of micro-organisms during ripening periods varying in length but fairly well-defined for each variety.

In contrast to the soft cheeses, the hard kinds are low in water-content, ripen more slowly and may be kept through much longer periods. They retain their form through a wider range of climatic conditions. They develop flavor slowly and correspondingly deteriorate much more slowly. Such cheeses are in marketable condition over longer periods. In their manufacture the cooking of the curd takes a prominent place.