12 Composition of Cheese. 



in the analyses of these two Stilton cheeses. The first was quite 

 mild in flavour in comparison with the other, and yet it contained 

 three times as much salt as the more saline-tasting older cheese. 

 The fact is, the saline taste is developed during the ripening of 

 cheese ; newly-made cheese, though strongly salted, is always 

 mild in taste. During the ripening of the cheese a portion of 

 the casein or curd suffers decomposition, and is partially changed 

 into ammonia ; the latter, however, does not escape, but com- 

 bines with several fatty acids formed in the course of time 

 from the butter. Peculiar ammoniacal salts are thus produced, 

 and these, like most other salts of ammonia, have a pungent 

 saline taste. The longer cheese is kept, within reasonable limits, 

 the riper it gets ; and as it ripens the proportion of ammoniacal 

 salts, with their pungent saline taste, increases. It can be 

 readily shown that old cheese contains a good deal of ammonia 

 in the shape of ammoniacal salts. All that is necessary is to 

 pound a piece with some quick-lime, when, on the addition 

 of a little water, a strong smell of spirits of hartshorn will be 

 developed. In well-kept, sound old cheese the ammonia is not 

 free, but exists in the form of salts, in which the base is ammonia 

 in combination with butyric, caprinic, caprylic, and other acids, 

 generated under favourable circumstances by the fats of which 

 butter consists. Ripe cheese, even if very old, but sound, in- 

 stead of containing free ammonia, always exhibits a decidedly 

 acid reaction when tested with blue litmus-paper. Rotten cheese, 

 on the other hand, is generally alkaline in its reaction, and 

 contains free ammonia. 



I have made a quantitative determination of the amount of 

 ammonia in old Stilton cheese, and found it to amount to 1*81 

 per cent. 



The first Cotherstone or Yorkshire Stilton was made near 

 Barnard Castle, in the Vale of the Tees, and sold at Is. per Ib. 

 It is highly esteemed in Durham and Yorkshire ; but, to my 

 taste, the cheese which I analysed is not to be compared with 

 good, genuine Stilton, nor is it equal in flavour to Cheshire or 

 Cheddar. 



Cotherstone cheese, it will be noticed, contains a very much 

 larger proportion of water than even new Stilton. This imparts 

 to it a smooth and apparently rich texture, but the proportion of 

 butter is not really as great as it appears to be, nor, in point of 

 fact, equal to that found in an average Cheddar. It has usually 

 a very strong taste, which would be decidedly objected to by 

 Cheshire or Gloucestershire factors. In its preparation a good 

 deal of whey appears to be left in the curd in mechanical com- 

 bination, and to be the principal cause of the strong taste and 



