io Colorado Experiment Station 
t 
cream has been gathered under sanitary conditions, with cleanliness 
in mind, all things being equal, a good quality of butter is to be ex¬ 
pected. However, this last condition exists so rarely that it can be 
passed by with mere mention. 
Now if it were possible to introduce into the fresh cream im¬ 
mense numbers of desirable bacteria which would give it a good 
flavor, and which would impart to the butter that “grassy" or “nutty” 
taste so much sought for, we might be able to control the flavor, in 
a measure, in spite of the unsanitary condition of the cream. The 
Starter fills this demand. 
The Nature of a Starter. 
Hastings (i) has defined a starter as “A quantity of milk in 
which acid forming bacteria have grown until the milk contains large 
numbers of them. The addition of the starter seeds the cream with 
great numbers of bacteria which are in a healthy condition and which, 
by their growth, cause the acid fermentation to progress rapidly and 
in a more definite manner than without the addition of the starter.” 
In other w T ords, the starter is the active agent involved in ripening the 
cream. 
Starters are of two kinds, commercial and natural, depending 
upon the method by which the bacteria are obtained. 
The Commercial Starter. 
Starters prepared by various commercial firms, where facilities 
are provided for careful bacteriological work, are known as commer¬ 
cial or pure culture starters. They usually contain but one species of 
germ and this one selected from many others for its peculiar butter 
making properties. To be a good starter, the culture must develop 
at ordinary temperatures, 68 degrees to 70 degrees F.; it must produce 
acid rapidly and in quantity sufficient to allow of exhaustive churn¬ 
ing; and it must be capable of producing substances which will impart 
to the butter the desired flavor and aroma. The bacteriologist, who 
prepares these cultures, has all of these points in mind when select¬ 
ing a specific germ, and for this reason more uniform and satisfactory 
results are to be obtained with the commercial starter than with the 
home made or natural starter which is apt to contain germs, good, 
bad and indifferent. 
The cost of these commercial products is so small in comparison 
with the benefits to be derived that their more general use is to be 
recommended. The initial cost of a starter is about fifty cents and 
by careful handling it can be propagated for an indefinite time. They 
are for sale under trade names such as Butter Culture, Flavorone, 
Lactic Ferment, etc., and can be procured directly from the manu¬ 
facturer or through any drug store. 
(t) Hastings: 181 , Wisconsin Exp. Station. 
