hey abound. The addition of starters made
from yeast cultures resulted in the production of the undesirable
condition.

~Mottled cheese.~ The color of cheese is sometimes cut to that extent that
the cheese presents a wavy or mottled appearance. This condition is apt
to appear if the ripening temperature is somewhat high, or larger
quantities of rennet used than usual. The cause of the defect is
obscure, but it has been demonstrated that the same is communicable if a
starter is made by grating some of this mottled cheese into milk. The
bacteriology of the trouble has not yet been worked out, but the defect
is undoubtedly due to an organism that is able to grow in the ripening
cheese. It has been claimed that the use of a pure lactic ferment as a
starter enables one to overcome this defect.

~Bitter cheese.~ Bitter flavors are sometimes developed in cheese
especially where the ripening process is carried on at a low temperature
in the presence of an excess of moisture for a considerable length of
time.

Guillebeau[213] isolated several forms from Emmenthaler cheese which he
connected with udder inflammation that were able to produce a bitter
substance in cheese.

Von Freudenreich[214] has described a new form _Micrococcus casei amari_
(micrococcus of bitter cheese) that was found in a sample of bitter
cheese. This germ is closely related to Conn's micrococcus of bitter
milk. It develops lactic acid rapidly, coagulating the milk and
producing an intensely bitter taste in the course of one to three days.
When milk infected with this organism is made into cheese, there is
formed in a few days a decomposition product that imparts a marked
bitter flavor to the cheese.

Harrison[215] has recently found a yeast that grows in the milk and also
in the cheese which produces an undesirable bitter change.

It is peculiar that some of the organisms that are able to produce
bitter products in milk do not retain this property when the milk is
worked up into cheese.

~Putrid or rotten cheese.~ Sometimes cheese undergoes a putrefactive
decomposition in which the texture is profoundly modified and various
foul smelling gases are evolved. These often begin on the exterior as
small circumscribed spots that slowly extend into the cheese, changing
the casein into a soft slimy mass. Then, again, the interior of the
cheese undergoes this slimy decomposition. The soft varieties are more
prone toward this fermentation than the hard, altho