82 - STATE BOARD OF AGRICULTURE. 



4. Fermentation of Milk. 

 Spontaneous fermentation. 



(a) Flasks of milk from a number of different sources kept for a 



week at room temperature- (70°F.). 



(b) Some of the same milks kept at 45°F. 



Acid fermentation — ordinary market milk (loppered), sterile litmus milk 



inoculated with acid-producing organisms, and a pure culture starter 6 



weeks old. 

 Gaseous fermentation— sterile milk in fermentation tubes inoculated with 



Bad. aerogenes, with lactose fermenting yeasts; also a flask of milk 



showing evolution of gas and a gassy curd. 

 Sweet curd fermentation — litmus milk inoculated with rennet-producing 



organisms. 

 Ropy fermentation — milk inoculated with a ropy milk bacterium- 

 Bitter milk fermentation — milk inoculated with bitter milk bacteria. 

 Color fermentation — plain milk inoculated with chromogens. 

 Alcoholic fermentation — Matzoon, Yoghourt, etc. 



5. Moldy Milk. 



Milk upon which is growing Oidium lactis, Mucor, Penicillium, Aspergillus. 



6. Starter Bacteria and Some of Their Work. 



Cultures (milk, agar and broth). Power of reduction (cultures in litmus 

 milk, methylene blue milk). Antiseptic influence towards other bacteria 

 (a flask of milk inoculated with starter compared with another flask of 

 same milk not inoculated). Their work which is made use of in dairy — 

 sweet milk vs. sour milk, sweet cream vs. ripened cream, sweet cream 

 butter vs. ripened cream butter, cottage cheese, etc. 



7. Preserved Milks. 



Sterilized sweet milk — flask of milk 4 months old. Evaporated milk. 

 Condensed whole milk and condensed skim milk. Dried milk (milk 

 powder). 



II. Butter. 



1. Bacteria in Butter. 



Plates from sweet cream butter and from, fresh ripened cream butter. 

 Plates from butter 10 days, 18 months and 4 years old. Plates from 

 butter on 12% salt agar. 



2. Storage Butter. 



Butter that has been kept outside north window for 30 days. Sample of 

 same butter kept in same place, but protected from light. Samples of 

 butter 18 months and 4 years old. Uncolored butter 3 years old made 

 from sterilized cream with pure cultures. 



3. Moldy Butter. 



Samples of uncolored butter with different molds as Penicillium, Aspergil- 

 lus, Mucor, Oidium. 

 Print in paper with molds growing upon it. 

 Other half of same print from which paper was removed. 



4. Oleomargarine. 



Plates showing germ count. 



III. Cheese. 



1. Bacteria in Cheese. 



Fresh and ripe Michigan cheese and plates showing germ count. Micro- 

 scopes showing bacteria in sections of fresh and ripe cheese. 



2. Cheese Ripening. 



Unripened cheeses — cottage cheese, Neuf-chatel. Ripened cheese — Ched- 

 dar, Edam, Swiss, Brick. Cheeses ripened with molds — Roquefort, 

 Camembert. Abnormal moldy spots on cheese. Bulged and gassy cheese 

 and germ causing it. Microscope showing section of Roquefort cheese. 



