MILK AND CREAM CONTESTS. 9 
Bottle and Cap— Perfect Score, 5. 
Bottles should be made of clear glass and free from attached metal parts. Caps should be sealed in their 
place with hot paraffin, or both cap and top of bottle covered with parchment paper or other protection 
against water and dirt. Deduct for tinted glass, attached metal parts, unprotected or leaky caps, partially 
filled bottles, or other conditions permitting contamination of milk or detracting from the appearance of 
the package. 
Note.— The card shown above was adopted in April, 1915, and is more nearly uniform in regard to its 
bacterial ratings than the old one. This one was not used in any of the contests mentioned in this bulletin, 
and is the third form adopted by the Dairy Division. 
BACTERIA. 
The samples are all plated for bacteriological examination on the 
same day. Standard methods of plating on agar are used, and the 
samples are incubated for 48 hours. In milk-contest work the dilu- 
tions used are 1 to 100 and 1 to 1,000 which give results close enough 
for such work. Any sample having fewer than 500 bacteria per 
cubic centimeter receives a perfect score, while any sample having 
more than 200,000 bacteria per cubic centimeter receives a zero. No 
attempt is made to differentiate between the kinds of bacteria 
present, only a quantitative analysis being made. It is a well- 
established principle that in the production of market milk all kinds 
of bacteria are to be excluded, so the awards are made on the basis 
of freedom from bacteria of any kind. 
As bacteria in milk are extremely undesirable, both from a health 
as well as from economic standpoint, the greatest weight on the 
score card is given to freedom from bacterial contamination, 35 out 
of 100 points being allowed for this item. 
FLAVOR AND ODOR. 
While not so important as bacteria in their relation to public health, 
the flavor and the odor of dairy products considerably influence their 
commercial value. If consumers are served with an unpleasantly 
flavored milk, they will either use less of it or will seek some other 
dealer whose products are more acceptable. The most common 
'^off flavors" and odors found in contest milk and cream are those 
produced by certain feeds and by the absorption of foul odors from 
the stable air. These defects will be considered more fully later in 
this bulletin. 
In scoring, it is best to allow the samples to stand for a short while 
in a warm room, as undesirable flavors and odors are more easily 
detected if the milk is slightly warm. So far as possible, the room 
where the scoring is done should be free from any odors. The milk 
should be mixed as much as possible before the cap is removed. 
When the cap is removed about half the contents of the bottle should 
be poured into a clean receptacle; by quickly placing the nose over 
the mouth of the bottle any odor present can be detected. 
22097°— Bull. 356—16- 2 
