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COLLECTION: GOAT HANDBOOK ORIGIN: United States DATE INCLUDED: June 1992 Extension Goat Handbook

This material was contributed from collections at the National Agricultural Library. However, users should direct all inquires about the contents to authors or originating agencies.

DOCN 000000043 NO E-6

TI GOAT CHEESE AU M. Loewenstein J. F. Frank

S. J. Speck; U. of Georgia, Athens

RV J. H. Wojchick; USDA- Eastern Reg. Res. Ctr., Philadelphia, PA DE Milk and Milk Handling

Text

1 Cheese is perhaps the first food to be manufactured that is

currently consumed by man. The oldest written records have references to cheese as a food. Today, cheese is available in an almost

innumerable variety of kinds, flavors and consistencies. Agriculture Handbook No. 54, Cheese Varieties and Descriptions, published by USDA describes over 400 varieties and indexes over 800 names. Why? The answer is that it is made by many different races of people under widely varying conditions all over the face of the earth. And the

people who eat it like the various flavors and consistencies produced.

2 For a better understanding of the art and sciences of cheese-making one needs to know what kind of product it is and how the manufacturing procedures developed over the years. Even though the varieties differ quite widely in composition, cheese can be characterized as a product made from milk in which the protein is coagulated and concentrated.

The collection of protein is accompanied by recovery of most of the fat in the milk by its entrapment in the curd. Other constituents in milk remain in the curd or are removed with the whey depending on their solubility (fat soluble vitamins and minerals associated with protein are retained in the curd; water soluble vitamins and minerals are passed off in the whey).

3 For centuries, cheesemaking has been a farm or home industry with the individual producer using surplus milk to make small batches of cheese. Goat cheesemaking in the US still follows this general

practice. It was, and still is to a considerable degree, an art; since the middle of the 19th century however, more and more cheese has been

made in specially equipped factories with greater application of

science in the manufacturing procedure. Milk from all species has been used for cheesemaking. Because more attention has been given to

increasing the productivity of the bovine species, a large proportion of commercial cheese is now made from cow milk; the milk from the buffalo, zebu, sheep and goat is also used extensively.

4 There are rather significant differences in the proportions of major components (fat, protein, lactose and ash) in the milk from these various species and there are also important differences in the

chemical nature of each of these components. Thus, it is to be expected that a given manufacturing procedure will produce cheese differing in flavor and consistency when made from the milk of different species.

The milk may even respond to the manufacturing procedure in a different way. Much of this difference can be minimized or eliminated by

adjusting or standardizing the composition of the milk from the various species to a common level before using it in cheesemaking. More about that later.

5 Just as the nature of the milk from which it is made causes

variations in the characteristics of the cheese, so can modifications of the manufacturing procedure. In spite of the development of the cheesemaking art over centuries by many individual practitioners, certain basic processes are common to all. Even though many

modifications of each may be utilized, the four basic steps in cheesemaking are:

1. Preparation of the cheese milk 2. Coagulation of the protein

3. Freeing coagulated protein (curd) from whey and collecting it into a defined mass.

4. Aging under controlled conditions to produce desired flavor and consistency.

6 In this discussion of goat cheesemaking, each step will be treated in some detail. In most of the material, there will be no special

methodology required for making cheese from goat milk, when compared with the use of milk from other species; when special techniques are required, they will be discussed at length. For more detailed

information on cheesemaking procedures than can be given here, refer to the book ''Cheese and Fermented Milk Foods'' by Frank V. Kosikowski, Edwards Brothers, Inc., Ann Arbor, Michigan distributor.

7 Preparation of Cheese Milk

The cheesemaker must have high quality milk to make high quality cheese. The production of high quality milk has been discussed before.

In summary, milk selected for cheesemaking must be free of objectionable flavor, free of all foreign materials, including

antibiotics, free of pathogenic organisms and contain relatively few

nonpathogenic bacteria and somatic cells.

8 Standardization

Probably the most important aspect of preparing milk for

cheesemaking is the standardization for composition, that is, adjusting the fat and protein content to the desired proportion. This is of

extreme importance for two major reasons: it is necessary in order to produce cheese which is legal in composition and to provide uniformity in the cheese made. Agriculture Handbook No. 51, ''Federal and State Standards for the Composition of Milk Products,'' is the most

comprehensive source of information on this subject. Those making cheese in the home for personal consumption obviously do not need to be greatly concerned about composition, but if cheese is to be sold in the market, it will have to meet some standard.

9 Making saleable cheese from goat milk will pose a problem in respect to composition. The problem arises from the fact that goat milk, collected from only a few does, is more variable in fat and protein content than is cow milk. Wide variation in those components results from having most of the milk producing animals at the same stage of lactation at any given time and also because mid-lactation, when fat and protein are expected to be low, usually comes in mid-summer when climatic conditions favor production of low fat, low solids milk.

Experience has shown that milk may vary from 2to 5 22568349762258770000000 mid-summer and late fall; milk solids-not-fat may vary from 7to 90r

more during the same time span. Cheese made from milk differing so widely in composition will vary in a similar manner. Also, the

cheesemaker may experience difficulty making cheese with the low fat, low solids milk.

10 How can the goat cheesemaker solve this problem? While any one making cheese for only personal consumption can just ignore the

situation and follow personal desire, those making cheese for sale cannot. To make cheese which is uniform in composition, which is legal, to be offered for sale, two conditions must be met. Provisions must be made to test the milk (and the cheese if possible) for its fat and total solids content, and a source of concentrated goat cream and goat milk solids-not-fat must be available. The Babcock Test is the

analytical tool most widely used to determine fat content of milk and cheese.

11 Although the test is quite simple and can be performed wherever cheese is made, it does require special equipment and supplies which are somewhat expensive. Total solids content is determined by drying a weighed sample to constant weight in an oven at 212F (100C) and

calculating the percent of sample found in the moisture free residue.

A very accurate scale must be used to weigh the residue. Sweet cream, if needed for standardization of cheese milk, can be obtained from the fluid milk. It probably will be necessary to have a centrifugal

separator to produce the needed cream since gravity separation of cream in goat milk is slow and incomplete. Since cheese is usually made from ungraded milk (or surplus Grade A milk) it is usually possible to add

nonfat dry milk (the only known source of nonfat dry goat milk is Ozark Milk Products, Yellville, Arkansas - it is not Grade A quality) to cheese milk to standardize the milk solids-not-fat content. Such standardization may be necessary to maintain the quality of cheese

when the milk solids-not-fat content of the milk decreases to less than 8 In the manufacture of any specific variety of cheese, it is

important to determine the ratio of fat to protein (or milk

solids-not-fat) needed to meet legal standards for that cheese, then standardize the cheese milk to that ratio.

12 Bacterial Quality

Most cheese making procedures involve controlled growth/activity of bacteria and/or enzymes in either the coagulation stage, the aging stage, or both. The necessary control may not be possible unless the cheese milk is unusually low in bacteria count or is pasteurized. Since it is possible that the milk may contain pathogenic microorganisms, it is very desirable (legally required in most states if the cheese is to be sold) that all cheese consumed when fresh be made from pasteurized milk. Some very competent cheesemakers who can be highly selective in the milk used for cheese, use unpasteurized milk for making those

varieties of cheese which must undergo prolonged aging -pathogenic organisms are supposedly destroyed in the aging process. Because heating milk causes some physical changes in its fat and protein components, pasteurization usually involves the least heat treatment permitted. In the cheese factory equipped with a continuous HTST

pasteurizer, treatment at 161F (71.6C) for 15 seconds is usual; in the home or small factory, pasteurization is best accomplished with a

treatment of 145F (62.7C) for 30 minutes. If volume justifies the cost, this may be done in a pasteurizer vat, but can be accomplished easily by placing the milk containing vessel (preferably a stainless steel, flat bottomed, rectangularly shaped container not exceeding 12 inches in height) in a shallow pan containing 1-2 inches of water over the heating unit. An accurate thermometer should be used. Heating and holding should be followed immediately by cooling the cheese milk to the setting temperature (the best temperature for obtaining

coagulation). For most cheese varieties, utilizing the production of lactic acid by rapidly multiplying bacteria to cause or aid in protein coagulation, the setting temperature should be in the range of 72-90F (22-32C).

13 Setting the Cheese

This term is associated with practice and procedures followed in coagulating the milk protein. The three processes most often involved are: (1) culturing the cheese milk with substantial numbers of

desirable bacteria (predominantly lactic acid forming) and controlling incubation conditions, the milk protein is coagulated when sufficient lactic acid is produced giving a titratable acidity (TA) of 0.50 0.55, pH of 4.6 - 4.9; (2) culturing the cheese milk with protease enzyme (rennet), incubating at favorable temperature until protein is coagulated - with very little change in TA or pH; the third procedure is a combination of one and two. In a modification of the first

procedure, no bacterial culture is used; instead of producing protein

coagulation by the more time consuming lactic acid formation by

bacterial growth, the acid may be added directly to the milk to produce almost instantaneous coagulation.

14 Each of the preceeding setting procedures is recommended for the manufacture of some specific variety of cheese. Most of the cheese varieties which are consumed fresh are set by an acid coagulation process; cheese varieties consumed after aging are generally made by the enzyme setting process. Specific examples of the application of these methods of setting follow. Cottage and pot cheese made from skim milk, Neufchatel made from whole milk, or cream cheese made from cream (12-15 22568349762258770000000000000000000000000000000000000000000000000000 procedures. If only bacterial culturing is used, the setting

temperature suggested is 72-80F (22-27C) and 8 to 16 hours is generally required to form the coagulated curd. If a combination of bacterial

culturing and enzyme coagulation is used, the range in setting

temperature should be 80-90F; the bacterial culture should be added and incubated for about an hour then the enzyme added. Coagulation should be completed in 4-6 hours. Several varieties of cheese may also be made by adding an acid directly to the milk to cause almost instantaneous coagulation. Acid materials which can be used include hydrochloric acid, lactic acid (purchased as a pure concentrate or in the form of very sour whey from cultured cheesemaking), vinegar (acetic acid), or citrus fruit (lemon, lime) juice. If these acidulants are added to warm milk, the coagulated protein will tend to be granular or grainy and is difficult to process into a smooth, creamy cheese. If the acidulant is added to very cold milk which is then slowly warmed without stirring to setting temperature, a smoother, less grainy coagulum will usually result. Cheeses which are aged 60 days or more, such as Cheddar, Brick, Blue, Camembert, or most Italian varieties, are generally set by the enzyme-only method, or by adding a very limited amount of bacterial culture followed by immediate addition of the enzyme material.

15 All of these varieties of cheese, normally made in the US from cow milk, can be made from goat milk. The following table is a summary of the setting conditions for some cheeses when made from goat milk. This table shows the conditions of greatest importance to the cheesemaker handling fairly large volumes of milk, but can serve as a guide to the home manufacturer also.

16 Curd Recovery and Treatment

Determining just the proper time to terminate the incubation phase and commence the curd recovery phase of cheesemaking is probably the most difficult decision required in cheesemaking. While there is an optimum for each cheese variety, the desired qualities or

characteristics are quite similar for all. For acid coagulated cheese, tests for titratable acidity or pH can be used to determine when

coagulation has occured. For enzyme coagulated cheese, or if the acid degree tests (TA or pH) cannot be made, other less objective tests can be made. Many experienced cheesemakers use the following test. Insert the thermometer into the coagulated milk at a 45 angle then lift the tip up through the curd and observe the way the coagulum breaks. The