250 THE FERMENTATION OF CHEESE 



power) of our bacillus, then the pitting will be normal ; whilst, if finally these 

 adverse influences be almost entirely lacking, " puffy " cheese results. No 

 rejection of this explanation is implied by the mention of the error into which 

 its author has fallen in attributing to his bacillus alone the capacity of producing 

 pitting the inaccuracy of which assumption has been noted, inter alia, by 

 ADAMETZ (VIII.). 



182. Cheese-makers' Recipes. 



In the light of Baumann's discovery, the reason for a number of (apparently 

 pedantic) rules current among cheese-makers both for the production and 

 subsequent treatment of the curd is made clear. The careful adherence to 

 certain temperatures during and after setting ; the time of exposure to their 

 influence ; the nature of the mechanical treatment, and even the extent of the 

 pressure applied to the moulded curd in the press, all these conduce to the 

 result the cause of which is certainly unknown to the operators that a certain 

 bacterial species attains pre-eminence. 



The researches published by FR. SCHAFFER (III.) and FREUDEXREICH (VIII.) 

 in 1895 ten d t elucidate the processes occurring during the after- warming of 

 the curd. As has already been indicated, the freshly precipitated curd is kept 

 for a short time at a certain constant temperature, the degree and duration of 

 exposure varying in different kinds of cheese. In the case of Emmenthal cheese, 

 Schaffer showed that a merely gentle after-warming of the curd results in a 

 quicker and more perfect ripening, so that the finished cheese contains a large 

 proportion of products formed by the decomposition of albumin. Freudenreich 

 investigated this condition from a bacteriological point of view, and explained 

 the fact already recorded in 177 viz., that the ripening of hard cheese is 

 almost exclusively brought about by bacteria, whilst that of soft cheese is chiefly 

 occasioned by higher fungi (budding fungi, oi'dium) as due to the inferior 

 powers of resistance to high temperatures exhibited by the latter organisms. 

 Thus the cheese-maker's old rule that "curd for soft cheese should be only 

 gently warmed " is shown to be well founded. 



Certain prescriptive methods of preparation for a large number of different 

 kinds of cheese have been gradually built up as the outcome of practical 

 experience. The possibility of such a result is a proof that the bacterial species 

 necessary in the ripening of cheese are present everywhere and at all times. 

 The exact observance of these recipes can, however, only continue to indefinitely 

 yield uniform results where the composition of the bacterial flora of the milk 

 set for cheese undergoes merely unimportant fluctuations. This is the case in 

 the Alpine dairies, where the grazing grounds seldom, if ever, receive any 

 application of manure from external sources, and consequently the same species 

 of bacteria are continually returned to the ground anew in the dung of the 

 grazing cattle. For this reason the cheese-dairying industry necessarily developed 

 first in the High Alps, since there the business is, in a bacteriological sense, 

 exposed to the minimum of danger. The case is different in the lowlands, 

 where the cows are fed with fodder of highly diversified origin, frequently 

 consisting of the residues of agricultural industries (grains, distillery residue, 

 grape skins, &c.). The bacterial flora of the dung of such animals will be liable 

 to frequent changes ; and since the bacterial content in the milk is for the most 

 part derived from the dung, it will be evident that the cheese-making process 

 will be affected by this change. Greater difficulties consequently attend the 

 pursuit of the industry in lowland districts, and much less reliance can be placed 

 on recipes. To explain this more clearly by an example, reference may be 

 made to an observation which chemists have been unable to explain, but which 



