MILK AND CEEAM CONTESTS. 9 



Bottle and Cap— Peefect Score, 5. 



Bottles should be made of clear glass and free from attached metal parts. Caps should be sealed in their 

 place with hot parafBn, 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 fuUy 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 



