No. 6. DEPARTMENT OF AGRICULTURE. 611 



Hansen's "Lactic Ferment" can be employed to advantage. The 

 amonnt of stafter to be used in i-ipeniug milk for cheese-making 

 should be from two to five pounds of starter for each hundred pounds 

 of milk. The amount will vary according to the temperature of 

 the air and the degree of acidity already in the milk when it comes 

 to the factory. Starters should not be prepared from the mixed 

 milk in the vat or from whev. 



(2.) How to Determine the Proper Degree of Ripeness. — Since ripe- 

 ness in milk means formation of lactic acid, we can measure the 

 ripeness of milk by determining the amount of lactic acid as in 

 the case of cream, but for cheese-making purposes this method 

 is not sufiiciently delicate. It has been pointed out above that the 

 activity of rennet is extremel}' sensitive to the presence of acid; 

 a very minute amount of acid greatly increases the activity of the 

 rennet and reduces the time in which it will coagulate milk. The 

 most satisfactory- test for ripeness in milk is to make use of the 

 rennet test in one of the forms described in the preceding section. 

 When milk is found to coagulate by the Monrad test in 45 to 60 

 seconds, or by the Marschall test in two and one-half spaces, enough 

 acid has developed to enable one to add the rennet for coagulat- 

 ing the milk in the vats. The effect of ripening milk is to hasten 

 the w^hole operation of cheese-making. The general aim is to have 

 such an amount of acid formed when the rennet is added that 

 the rest of the operation con be completed in six hours. Milk con- 

 taining as much as two-tenths of one per cent, of lactic acid when 

 brought to the factory ip overripe and liable to make trouble in 

 cheese-making. Overripe milk usually causes losses of extra amounts 

 of fat and decreased yield of cheese, since it is difficult for the cheese- 

 maker to control satisfactorily the different operations of cheese- 

 making. 



CHAPTER VITI. 



MAKING CHEDDAR CHEESE. 



There are two methods in use for making the kind of cheese most 

 commonly found in our American markets, (1) the "stirred curd," 

 or ''granular"' method, and (2) the cheddar method. The latter 

 is probably more extensively used now. The product is essentially 

 the same, though it is claimed for the cheddar system that the tex- 

 ture of the cheese is more solid, and the product more generally 

 uniform, and with a somewhat smaller content of moisture. We 

 shall describe onlv the cheddar method. 

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