[Ill.u.s.tration: FIG. 48.--Filling the hoops and pressing the curd.]
The commonly used gang press may or may not have an arrangement to cause continuous pressure to be applied to the cheese (Figs. 47, 48). When fresh cheeses are first placed in the press, the pressure should be applied very gradually. The curd, after being cut through the mill, will have many exposed fat globules. A heavy pressure at first will force out the whey set free by the extracting power of the salt. The whey will carry away the exposed fat globules, and therefore reduce the yield. As soon as white whey starts from the hoops, the increased application of the pressure should be stopped until the whey regains the appearance of clear brine. More pressure can then be gradually applied until full pressure is reached. The cheeses should remain under heavy pressure for one-half to one hour, when they should be removed from the press and dressed.
+207. Dressing the cheese.+--When ready to dress the cheese, the press is opened and the hoops turned down. The hoops are opened so that the bandages can be lapped over the top of the cheeses about 1 inches.
Before turning a bandage down, it should be carefully pulled up to remove any wrinkles from the sides of the cheese, but not hard enough to pull it free from the bottom. After it is pulled up, the bandage should be lapped over the top about 1 inches, and if not even should be trimmed with a sharp knife. It should then be sopped down with warm water. Plenty of warm water to wet the bandage and cloths helps to form a good rind. If starched circles are used, one should be placed on the top of the cheese and sopped down with warm water. If not, the press cloth should be wrung out of warm water and put on smoothly, so there will be no wrinkles. The hoop is then put together and placed back in the press under heavy pressure for twelve to eighteen hours. The pressure should be sufficient to cause the curd particles to unite so that the surface of the cheese will be smooth. The next day the cheeses are taken from the hoops and placed in the curing-room. If they do not come out of the hoop easily, they may be loosened by cutting between the sides of the cheese and the hoop with a knife. A special thin-bladed knife for this purpose is called a speed knife (Fig. 49). Care should be taken not to cut the bandage when trying to loosen the cheese. If starched circles are used, the press cloths are removed from the cheese, when they are put in the curing-room. If neither starched circles nor press cloth are left on the cheese in the curing-room, the rind will crack on account of drying out on the exposed surface. This allows mold and insects to enter the cheese. The flavor, body and texture and color of the cheese are all dependent on the skill of the cheese-maker and the quality of the milk from which it is made. The finish is dependent entirely on the skill and carefulness of the maker. An operator should see that the cheese press is straight so that there will be no crocked cheese and that the bandage and press cloths are properly put on, because the finish or appearance of the cheese is an index of his ability.
[Ill.u.s.tration: FIG. 49.--Speed knife.]
+208. Handling over-ripe and ga.s.sy milk.+--Because it is sometimes necessary to make over-ripe[91] or ga.s.sy milk[92] into cheese, special directions or precautions are necessary. The best way is to reject this milk. When it is necessary to make it into cheese, the losses are much more than with normal milk. It is a question of making as good a cheese as possible, and the subject of losses is ignored.
(1) _Over-ripe milk._--The fact that the milk is over-ripe shows that there is already too much acid present. Every effort must be made to get the curd as firm as possible in the whey with the acid development as low as possible or before the acid has had time to develop any more than can be helped. Although the milk is over-ripe, it is a good plan to add about of 1 per cent of starter just before the rennet. This starter will not begin to work until the curd is being cheddared and it will help the flavor, especially if any bad fermentation should be present.
The rennet is added at 80 F., as this lower temperature tends to check the acid development. More rennet is used, commonly from 4 to 4 ounces to 1000 pounds of milk. This gives a quicker coagulation. The curd is cut soft, as this tends to expel the moisture more quickly. The heat is turned on sooner after cutting. The time to turn it on and the length of time to heat are determined by the amount of acid. A curd should not be heated in less than fifteen minutes. If the curd has enough acid and has not begun to firm up much, the whey should be drawn down to the surface of the curd, water the temperature of the whey and curd put into the vat, and the curd firmed up in this water. The water washes the acid out of the curd and because of the lack of milk-sugar checks the acid development.
If the milk is not so ripe and the curd nearly firm enough, the whey may be drawn off and the curd firmed up by hard stirring in the vat or sink.
The curd should not be pushed back enough to be very deep or thick when ready to cheddar.
The curd should be cut into very small pieces to cheddar. The smaller the pieces, the faster the whey drains away. Sometimes it is necessary to cut the curd into pieces six inches square. The pieces should not be piled but should be turned often and stood on edge to let the whey drain away and sometimes pressed with the hands to force the whey out. It is often all one man can do to keep the curd turned.
[Ill.u.s.tration: FIG. 50.--At the left is a regular shaped, close, solid textured cheese; at the right one puffed up with gas.]
The curd is not cheddared very long but is milled early so that the whey can escape. If it is thought that the cheese will be sour, the curd should be washed in cold water to remove the acid and milk-sugar. A little more salt is sometimes used. A product made from over-ripe milk, no matter how skillful the cheese-maker, will show traces of a sour cheese.
(2) _Ga.s.sy milk._--If a cheese-maker knows that there is "ga.s.sy"
fermentation, he should add more starter and develop more acid when ripening the milk to try to overcome this. There are different kinds of ga.s.sy fermentation. Some produce acid and some do not. Some will not show until the cheeses have been on the curing-room shelves several days. Others will cause the curd to float in the whey. Usually the gas shows as pin-holes while the curd is being cheddared.
[Ill.u.s.tration: FIG. 51.--This shows the same cheeses as in Fig. 50, cut open to show the solid and ga.s.sy texture.]
The gas causes tiny round holes in the cheese, resulting in the cheese swelling or puffing out of shape and sometimes breaking open (Figs. 50, 51). The only time to overcome the gas is during the cheddaring process.
The curd is piled and repiled until the holes flatten out. This shows that the gas-producing organisms have weakened and will not cause any more holes. Because the curd has to be piled so many times and so long, the pieces become very thin. The curd is ready to mill when most of the holes have flattened. After milling, the curd should be stirred and aired for some time before salting to allow the bad odor to escape.
Because of the high acid development, it often happens that the cheese will not be ga.s.sy but will be sour. At best a cheese made from milk having ga.s.sy fermentation will have a bad flavor. The quality of the cheese can be no better than that of the milk from which it is made, plus the skill of the cheese-maker.
+209. Qualities of Cheddar cheese.+--The cheese should be neat, clean and attractive. If unclean, and the bandage not put on the cheese properly, it shows that the manufacturer is not particular to keep the curing-room shelves tidy nor careful and painstaking in dressing. The cheese should not be lopsided or bulged. When cut, it should have a uniformly colored interior. The princ.i.p.al color defects are too high, or too light color, mottled or seamy. The texture should be solid and close. A common defect is mechanical holes or openings and another is gas pockets. The body can be tested by rubbing the cheese between the thumb and fingers. It should be smooth and waxy and free from lumps. It should rub down like cold b.u.t.ter. The common defects are graininess and lumpiness. Graininess may be caused by too much acid or too much moisture in the cheese. Lumpiness is due to uneven curing. If too much moisture is present, the body will be soft and mushy; if not enough moisture, the body will be hard and dry.
The cheese should have a pleasant, clean, mild aroma and the characteristic flavor which is usually somewhat similar to that of nuts and so is spoken of as a nutty flavor.
CHAPTER XIII
_COMPOSITION AND YIELD OF CHEDDAR CHEESE_
So many factors affect the composition and yield of Cheddar cheese that no positive or exact statement can be made unless other facts are definitely known. The following factors affect both the composition and yield:
1. The chemical composition of the milk.
2. Amount of moisture incorporated into the cheese.
3. The amount of solids lost in cheese-making.
4. The skill of the cheese-maker.
5. The bacterial-content of the milk.
+210. Composition of milk, whey and cheese.+--The following Tables[93] VI, VII, VIII, which are the average of forty-eight factories for the season of 1893, show the minimum, maximum and average composition:
TABLE VI
AVERAGE COMPOSITION OF THE MILK
MinimumMAXIMUMAVERAGE ----------------------------------------------- Water86.2888.3087.28 Total solids11.7013.7212.72 Fat3.304.403.77 Casein2.202.852.48 Alb.u.min0.520.810.69 Sugar and ash, etc.5.635.895.78
TABLE VII
AVERAGE COMPOSITION OF THE WHEY
MinimumMAXIMUMAVERAGE ----------------------------------------------- Water92.7593.2893.00 Total solids6.727.257.00 Fat0.240.510.38 Casein, alb.u.min0.660.990.86 Sugar, ash, etc.5.635.865.76
TABLE VIII
AVERAGE COMPOSITION OF THE GREEN CHEESE
MinimumMAXIMUMAVERAGE ----------------------------------------------- Water33.1643.8937.33 Total solids66.8456.1162.67 Fat30.0035.8933.41 Casein20.8025.4823.39 Sugar, ash, etc.4.867.025.89
Table VI shows the minimum, maximum and average composition of the milk and Table VIII the composition of the cheese made from that milk. The average composition of the cheese in Table VIII shows that it contains 37.33 per cent of water. The tendency to-day seems to be for a softer cheese so that the average would probably be higher. Table VIII also shows the wide variation in the composition of the cheese. The moisture and total solids both vary about 10 per cent. In order to judge the variation in composition, one must know the composition of the milk and the moisture-content of the cheese and then only a very inaccurate estimate of the composition of the cheese can be formed.
+211. Relation of fat to casein in normal milk.+--In order to understand the relation of the composition of the milk to yield of cheese, one must be familiar with the relation of the fat to the casein in normal milk.
The following table[94] shows the relation of fat to casein in normal milk:
TABLE IX
SUMMARY SHOWING THE RELATION OF FAT TO CASEIN IN NORMAL MILK
====================================================================AVERAGEAVERAGEAVERAGEPOUNDS OFPER CENTNUMBERPER CENTPER CENTCASEIN FOR GROUPOF FAT INOFOF FAT INOF CASEINEACH POUNDMILKSAMPLESEACH INEACHOF FAT INGROUPGROUPMILK --------+-----------+----------+-----------+-----------+------------ I3.0-3.5223.352.200.66 II3.5-4.01123.722.460.66 III4.0-4.5784.152.700.65 IV4.5-5.0164.743.050.64 V5.0-5.2575.133.120.61 ====================================================================
Table IX shows that the pounds of casein for each pound of fat are not constant but that the casein does not increase in proportion to the fat above 4.0 per cent of fat in the milk.
+212. Influence of fat in milk on yield of cheese.+--The following table shows the influence which fat in the milk has on the yield of cheese:[94]
TABLE X