The analysis of food and drugs / by T.H. Pearmain and C.G. Moor.

  • Pearmain, T. H. (Thomas Hames)
Date:
1897-1899
Catalogue details

Licence: Public Domain Mark

Credit: The analysis of food and drugs / by T.H. Pearmain and C.G. Moor. Source: Wellcome Collection.

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    therefore his efforts have to be directed towards the restraint of the growth of injurious organisms, and 4;owards the development of those that are desired, so that it is obvious that his efforts may, through the skill and know- ledge attained by experience, be attended with uniform success, but cannot be expected to be invariably successful. As above stated, the application of sufficient heat to sterilize milk produces alterations in the casein which interfere with the action of rennet, and causes the curd to lose its power of coherence. ' There is no doubt that the different kinds of cheese owe their particular property or characteristics to the action of definite bacteria, or classes of bacteria. Since it is possible to prepare any kind of cheese from a given quantity of milk in a given place, or at any time, and according to its nature to obtain it from this milk, it follows that all* the kinds of bacteria which are necessary for the manufacture of the cheese in question must be present universally and invariably in the milk. These bacteria must have an extraordinarily wide occurrence. The art of cheese-making consists in the preparation of the fresh cheese mass of each different kind in such a way that those kinds of bacteria which are active in the ripening of that particular cheese must be developed to a predominant extent' (Fleischmann). The following general process of cheese-making applies with modifications to the manufacture of every kind of cheese. The milk, whether in its natural condition or with added or abstracted fat, is warmed up to 80° F. or above, and curdled by the addition of rennet. Sometimes rennet is not employed, and curdling is effected by the acidity pro- duced by certain of the bacteria commonly found in milk. After curdling has taken place the curd is then cut up by means of an apparatus specially designed to divide it