June ig, 1914 
Flavor of Cheddar Cheese 
191 
(4) The flora of raw-milk cheese is varied and consists of all the 
varieties into which the four groups were divided. 
(5) The flora of pasteurized-milk cheese, with the exception of the 
Bacterium casei group, is dependent upon the flora of the starter. 
(6) The Bacterium casei group is apparently responsible for the 
pungent taste that develops late in the ripening period of both raw-milk 
and pasteurized-milk cheeses. It is probable that growth of this group 
continues during the major part of the ripening period. 
(7) The action of two or more organisms growing together is not the 
sum of their individual actions when growing alone. When growing 
together, they may attack substances that neither can attack alone, or 
they may produce a larger quantity of acid than the sum of the quantities 
that either can produce alone. 
(8) When added to pasteurized milk, the organisms of the Bacterium 
casei group produce a sour taste in the cheese during the early part of 
the ripening period. 
(9) No Cheddar flavor is obtained in pasteurized-milk cheese when 
the organisms of the Bacterium lactis acidi group alone are used as 
starters. The varieties that are able to ferment the more complex 
substances are likely to produce a bitter taste. 
(10) Starters composed of both Bacterium lactis acidi , b, and Strepto¬ 
coccus, b, when added to pasteurized milk, improve the quality of the 
cheese. It does not seem unreasonable to hope that starters may be 
obtained that will give the characteristic Cheddar flavor to the cheese 
prepared from pasteurized milk. 
LITERATURE CITED 
Ayers, S. H. 
1913. Casein media adapted to the bacterial examination of milk. In U. S. 
Dept. Agr. Bur. Anim, Indus., 28th Ann. Rpt. 1911, p. 225-235. 
Currie;, J. N. 
1911. A study of the optical forms of lactic acid produced by pure cultures of 
Bacillus bulgaricus. In Jour. Biol. Chem., v. 10, no. 3, p. 201-211. 
Gordon, M. H. 
1905. Report of some characters by which various streptococci and staphylococci 
may be differentiated and identified. In 33d Ann. Rpt. Gt. Brit. 
Local Govt. Bd. 1903/04. Sup. Rpt. Med. Off., p. 388-430. 
Hart, E. B., Hastings, E. G., Flint, E. M., and Evans, Alice; C. 
1914. Relation of the action of certain bacteria to the ripening of cheese of the 
Cheddar type. Jour. Agr. Research, v. 2, no. 3, p. 193. 
Hastings, E. G., Evans, Alice; C., and Hart, E. B. 
1912. The bacteriology of Cheddar cheese. U. S. Dept. Agr. Bur. Anim. Indus. 
Bui. 150, 52 p., 4 fig. Also issued as Wis. Agr. Exp. Sta. Research Bui. 
25, under the title, Studies on the factors concerned in the ripening of 
Cheddar cheese. 
