Apr. 15, 1914 
Flavor of Roquefort Cheese 
7 
From the data in Tables IV and V and from observations on numerous 
other cheeses, which have been distilled without making complete 
analyses of the distillates, we conclude that a well-flavored Roquefort 
cheese will have a distillation number (c. c. of decinormal alkali to 
neutralize the distillate from 100 grams of cheese) of 30 to 60; one 
showing a slight growth of mold and very little flavor will have a dis¬ 
tillation number less than 30; and a cheese thoroughly permeated with 
mold and highly flavored will have a distillation number above 60, and 
in extreme cases this number may even exceed 100. 
RELATION OF THE VOLATILE ACIDS TO FLAVOR 
In discussions of the properties of this homologous series of saturated 
fatty acids, a fact of very peculiar interest is commonly overlooked— 
namely, the pronounced changes in taste with increasing molecular 
weight. The lower members are distinctly sour and in dilute solutions 
can not be distinguished from the mineral acids by their taste. This 
sourness diminishes with increasing carbon content and can not be 
detected at all in those containing more than 7 carbon atoms. Valeric 
acid, with 5 carbon atoms, has not only a sour taste but also a distinct 
peppery effect. This peppery effect increases with increasing molecular 
weight and is very pronounced in caprylic and capric acids. The higher 
acids of this series, containing 12 or more carbon atoms, have no 
well-defined taste. Thus, it is seen that the group of acids containing 
from 5 to 10 carbon atoms, which includes the three volatile acids of 
milk fat—caproic, caprylic, and capric—is characterized by this burning 
or peppery effect on the organs of taste. 
Volatile acids have been vaguely connected with the aroma and flavor 
of dairy products by numerous investigators, but to our knowledge the 
peculiar peppery effect of the green-mold cheeses has never been spe¬ 
cifically attributed to this group of volatile, difficultly soluble acids of 
milk fat. Duclaux (7, p. 288), in a discussion of Cantal cheese, states 
that “The sharp taste of old cheese is in large part due to the fixed fatty 
acids and their salts, which have a burning effect on the palate and 
tongue.” Just what Duclaux meant by “fixed” acids is not quite plain, 
but certainly his observation is applicable only to the volatile acids. We 
believe that the unmistakable similarity between the effect on the gusta¬ 
tory nerves of well-ripened Roquefort cheese and these volatile acids 
entirely justifies the conclusion that the peppery taste of the cheese is 
due to the accumulation of these acids and their readily hydrolyzable 
salts. 
This explanation is not offered as a solution of the entire problem of 
the flavor of Roquefort cheese. This is rather to be interpreted as an 
endeavor to identify a single prominent component of the flavor and to 
explain its occurrence in the cheese. 
