Student material

3. classifications of cheese based on
moisture
• Fresh: (aka country cheeses) are soft, whitish in color and
mild tasting (i.e., cottage cheese, cream cheese, ricotta,
farmer's, pot, and feta cheeses. Moisture content is over
80%
Soft: Brie, Camembert, and many hispanic cheeses. Water
content ranges from 50-75%.
Semi-hard: 40-50% moisture. Roquefort, blue, Muenster,
brick, gouda, edam, port du salut, gorgonzola, and stilton.
Hard: moisture content is 30-40%. Cheddar and Swiss.
Very hard: Parmesan and Romano. Will not slice easily, but
are easily grated or crumbled. water content is approx 30%.

4. Steps in cheese making
1. Milk selection.
2. Coagulation,
3. curd treatment, (cutting, heating, salting,
knitting, and pressing),
4. curing, and
5. ripening.)

5. Why is homogenized milk preferred for
cheese making?
• It is preferred for soft cheeses makes it makes the
casein proteins coagulate more easily and the
increased surface area of the broken-up fat
results in a moister product. It is not used to
make hard cheeses, it creates a brittle texture.
• Homogenization is the process of breaking down
the fat molecules in milk.

6. 1st stage
2nd stage
3rd stage
3rd stage
3rd stage
4th stage

10. Coagulation by acification

11. Coagulation by Enzymes

12. Coagulation
• Coagulation is the process in which the
clotting or precipitation of protein in a liquid
into a semisolid compound.
• Cheese making starts with the coagulation of
the casein protein in milk. The whey, which
contains most of the water in milk, is
removed as the curd forms. The protein, fat,
and micro nutrients from milk are hence
concentrated within the curd.

13. Distiniguish between the two types of
coagulation.
• Enzyme C: The enzyme most commonly used is rennin,
obtained from milk-fed calves --specifically their fourth
stomach. Rennin is also called chymosin and can be sold
commercially as rennet. Enzymes may be derived from
bacteria starters, from molds, or any other
microorganism.
Acid Coagulation:There are two methods that acid may be
used to coagulate milk proteins and this form cheese. The
first method is simply to add acid directly to the milk. The
second is to inoculate the milk with a bacterial starter
culture that acidifies the milk by converting lactose (milk
sugar) to lactic acid

14. Which coagulation process reults in the highest
amount of calicium in the curd?
• Enzyme Coagulation
"As the curd forms, the whey separates, but
most of the milk's calcium remains in the curd.

22. Why is cheese cured and ripened?
• The aging process converts bland, tough,
rubbery, fresh curd into unique cheese with its
own mature flavor, aroma, and texture.

23. classes of cheese (and an example)
based on their ripening method.
• Bacterial Ripened:
-Internal; cheddar, colby, edam, gouda, gruyere,
parmesan, provolone, romano, swiss.
-External; Bel Paese, brick, liederkranz, limburger,
monterey jack, muenster, port du salut, trappist.
Mold Ripend:
-Internal; Blue, Gogonzola, roguefort, stilton.
-External; Brie, Camembert

24. What chemistry things happened during ripening (Chemist
Corner 11-3)
• There are three main steps in ripening of cheese. The first
step is glycolysis, in which lactose is metabolized to form
acetic and propionic acid, carbon dioxide, esters, and
alcohols; this metabolism is initiated by te bacterial starter
and other microbials present in milk.
Next is lipolysis, the breakdown of fat molecules to free
fatty acids, which are then further broken down to ketones,
lactones and esters by enzymes found in milk or added
during manufacturing.
The final step is proteolysis, the breakdown of proteins
called caseins into peptides (small protein fragments) and
amino acids. This is performed by enzymes found in the
milk and by microorganisms from the start and found
naturally in milk.

26. How do bacteria influence cheese flavour
• Bacteria are responsible for some of the
flavors found in cheese. Certain strains of
bacteria produce lactic acid, which affects the
degree of sharpness of mildness of cheese.
Lactic acid bacteria are believed to impart
flavor to cheese by reducing the oxidation --
reduction potential, by protein hydrolysis, and
by producing dicarbonyls.