24 BULLETIN 970, U. S. DEPARTMENT OF AGRICULTURE. 
ing the figures for each scraping. The loss in cows'-milk Roquefort 
seems to be somewhat less than that of sheep's-milk Roquefort. This 
may be due to a difference in the nature of the two milks or to a more 
vigorous development of the slime organism in the case of sheep's- 
milk cheese. At any rate the rather heavy losses that occur in the 
domestic and foreign cheeses indicate that these losses are normal and 
that probably this fermentation is rather to be encouraged than dis- 
couraged even though the losses may seem somewhat heavy. 
USE OF TIN FOIL. 
The function of the tin foil is to prevent desiccation, excessive 
oxidation, and the escape of the volatile substance from the cheese. 
After the last scraping the cheeses are wrapped in tin foil. There 
always seems to be an improvement in the quality of the cheeses 
wrapped in foil as compared with those not handled in this manner. 
Curing the cheese in the foil for a time appears to aid in the develop- 
ment of the sweet flavor and reduces to a minimum the strong, biting, 
and soapy flavors which may occur when the cheese is exposed too 
long to the action of the air. Because of the ripening changes going 
on within the cheese it has a slightly higher temperature than the 
surrounding air. The tendency of the moisture of the cheese to 
condense when covered with the foil and held at a low temperature 
must cause a circulation of the ripening agents. Here the foil acts as 
a condensing medium, prevents the escape of liquid and volatile sub- 
stances, and the surface of the cheese tends to have the same homo- 
geneous texture and composition. 
The use of paraffin as a substitute for tin foil has not proved to be 
satisfactory. Unless the surface of the cheese is very dry the paraffin 
does not adhere readily in a coating of less than about J inch. A 
normal cheese is entirely too soft for a thin layer of paraffin, such as 
might be used with Cheddar cheese. Because of the soft nature of the 
cheese and because the surface of the coating may readily be broken 
the paraffined cheese is sure to suffer from lack of protection from 
the dry air. When foil is used the cheese is better protected and 
may be wrapped more easily and securely with parchment paper. 
While tin foil as a covering is more expensive than paraffin, it is 
more efficient and more attractive in appearance, so that the additional 
expense seems justifiable when the value of the product is considered. 
Shrinkage. — The loss from shrinkage will vary, depending upon 
the moisture content of the cheese when enveloped in foil and the 
temperature and length of time held before shipment. With 16 
cases of cheese held for a period of five months, at a temperature of 
from 45° to 50° F., there was an average loss in weight of 4.58 per 
cent. These cheeses were a little too moist when wrapped in foil. 
