64 
Composition of Cheese. 
g. — That an excess of acid coagulates milk, but not perfectly in 
the cold. 
h. — That a moderate amount of acid does uot coagulate milk in 
the cold, and imperfectly at an elevated temperature. 
6. Cheese, again, is sometimes spoiled when bad annatto is 
employed as a colouring matter. Annatto at the best is a nasty, 
disagreeable smelling substance ; it would be well if it were 
banished altogether from the dairy. But, so long as a good many 
people will prefer coloured to uncoloured cheese, annatto will be 
employed for the purpose of imparting a more or less deep 
yellow colour. 
The annatto of commerce is derived from the Orlean-tree 
{Bixa orellana). The seeds and pulp of this tree appear to 
contain two colouring matters ; one, in a pure state, is orange- 
red, and is called bixin ; the other is yellow, and called orellin. 
These colouring matters are insoluble in water, but dissolve 
readily in alkalies, and also in fixed oils and fats. Solid 
annatto, the annatto cake of commerce, is a preparation, which 
contains, besides the pure colouring matter, a great deal of potash 
or soda, carbonate^of-lime, pipeclay, earthy matters, and rubbish 
of various kinds. Soap, train-oil, and other disagreeable smelling 
and tasting matters are often used in preparing annatto cake. 
Hence the annatto of commerce is often a most nauseous mate- 
rial, which, when put into the cheese-tub, is apt to give to the 
cheese a bad taste and an unsightly colour. Far superior to this 
annatto, and more handy in its application, is the liquid annatto, 
which is mainly an alkaline solution of the pure colouring 
matter of the Bixa orellana. An excellent solution of that 
description is manufactured by Mr. Nichols, of Chippenham, 
which is perfectly clear, has a bright yellow colour, and is free 
from any of the obnoxious and disagreeable substances which are 
frequently mixed up with annatto cake. 
7. In the next place, I would observe that cheese is occasionally 
spoilt if too much salt is used in curing it. Salt is a powerful 
antiseptic, that is, it prevents fermentation ; hence we use it for 
pickling beef and hams. A certain amount of salt is necessary, 
not so much for giving a saline taste, as for keeping in check the 
fermentation to which cheese, like other animal matters, is 
liable. If no salt were used the cheese would putrefy, and 
acquire a very strong taste and smell, at least when made in the 
ordinary way. When an extra quantity of cream is put to the 
milk, it is not necessary, or even desirable, to salt the curd 
much ; we might even do without salt altogether, for the large 
amount of fat (butter) in extra rich cheeses, such as Stilton or 
cream-Cheddar, sufficiently preserves the casein. 
If salt is employed in excess, the cheese does not ripen pro- 
