June 15,1914 
Flavor of Cheddar Cheese 
179 
have been made of the milk cultures which have been mentioned as a 
part of the routine method of cheese analysis. There is in nearly every 
series a general decline as the emulsion used for the inoculation becomes 
more and more dilute. The two series presented in Table X illustrate 
the point. The titrations were made after 28 days incubation at 35 0 C. 
and the acidity calculated as lactic acid. 
Tabled X .—Decline in acidity with increasing dilutions of cheese emulsion used for 
inoculation of milk cultures 
Cheese No. 312 C. 
Cheese No. 309 C. 
Dilution. 
( 
Percentage 
of acidity. 
Dilution. 
Percentage 
of acidity. 
1:100,000. 
I. 60 
1* 55 
1. 22 
.78 
(») 
! i 
i :io,ooo. 
i *54 
i *45 
1. 50 
1.18 
r. 00 
( a ) 
1:1,000,000. 
1:100,000. 
1:10,000,000. 
1:1,000,000. 
1:100,000,000. 
1:10,000,000. 
1:1,000,000,000. 
IIIOO.OOO.OOO. . . j 
i : 10,000,000,000. 
1:1,000,000,000.j 
i 
a No growth. 
The lower percentage of acidity with every tenfold dilution indicates 
that in each dilution there were present certain varieties of organisms 
in such small proportions that they did not occur in the next higher 
dilution. Out of 345 series of titrations the decline was without a break 
in 56 per cent of the cases; in 37 per cent of the cases there was a general 
decline, but with one or more breaks; in only 7 per cent of the cases was 
this decline not apparent. 
THE VARIATION IN CHEESE FLORA 
It is evident from Tables VIII and IX that the normal flora of Ched¬ 
dar cheese is varied, with varieties of all four groups of cheese organisms 
in numbers ranging from hundreds of thousands to billions per gram of 
cheese. The flora in two equally good cheeses will contain each of the 
four groups of cheese organisms, but will differ as to the varieties present. 
There will also be a variation in the proportion of organisms of any single 
group. It does not appear that it is essential to good flavor to have any 
single variety present in very high proportions. One cheese may con¬ 
tain a given variety in high proportions, whereas another cheese may 
have this variety in such low proportions that it does not make its ap¬ 
pearance in a bacteriological analysis. To illustrate: Streptococcus “b,” 
which formed 30 per cent of the flora of cheese No. 36 (Table VIII), was 
isolated from onlv 6 of the 17 cheeses whose flora are presented in Tables 
VIII and IX. 
This variation of flora, with a constancy to the general type of growth, 
is to be expected under any ecological conditions determined by natural 
