Ch. 1: Raw Materials of Cheese - Questions Flashcards
how much fat is in partially skimmed milk?
1.5%-1.8% fat
how much fat is in skim milk?
between 0-0.5% fat, average of 0.1
when is lambing season?
January to May and through autumn
how much milk does a sheep produce per year?
400 to 1100 pounds
when is kidding season?
late August to early January
name the milk types from lowest to highest fat
goat, cow, sheep, buffalo
name the milk types from lowest to highest protein
sheep, cow, goat, buffalo
how long is a cow’s lactation period?
305 day lactation period
how long is a goat’s lactation period?
280 day lactation period
how long is a sheep’s lactation period?
245 day lactation period
how often are animals typically milked?
twice a day
how does milking time effect the milk quality?
morning milk is lower in fat vs afternoon milk
how does mastitis effect the milk of the infected animal?
leads to increased antibodies, and higher enzyme activity, which breaks down fats and proteins faster
what are the 4 primary functions of cultures in cheesemaking?
- production of lactic acid
- prevention of unwanted microorganisms
- ripening enzyme development
- gas, flavor, and aroma development
why would a cheesemaker use cultures from previous milkings?
used to start the process more quickly on the next day’s batch since it had more time to convert lactose in the leftover milk
what is a culture’s role in flavor, texture, and aroma development?
starter bacteria die and break open, releasing enzymes and alcohols that aid in development
what styles of cheeses use mesophilic cultures?
fresh cheeses, bloomy rinds, washed rinds, blues, cheddar-styles, gouda styles, havarti, feta
anything not heated more than 102F
what are the two groups of mesophilic cultures used in cheesemaking?
- lactic acid starter bacteria: create lactic acid
- aroma-producing bacteria: CO2 and flavor
what styles of cheese use thermophilic cultures?
cooked cheeses, alpine styles, and yogurt
anything heated over 130F
why would a cheesemaker choose to preserve natural cultures?
- tradition (parm regg and comte need these legally)
- terroir
why would a cheesemaker choose to avoid natural cultures?
- inconsistent results
- labor intensive
- high risk of contamination
what are the sources of cultures?
- a culture house
- direct vat inoculation (freeze dried)
- bulk set cultures (frozen liquid)
- house culture
- mother culture(initial starter culture)
what are the advantages to using a culture house made bacteria set?
gives makers control over the amounts and types developed
what is the advantage to using direct vat inoculation cultures (freeze dried)?
- added directly to cheese vat
- quicker acting than liquid based cultures
what is the advantage of using bulk set cultures?
- prepared fresh daily
- replacement for mother cultures
what is the advantage of using house cultures?
can be a much better expression of art and science in cheesemaking
what is the ideal storage temperature for cultures?
-75C to -80C (-103F to -121F)
where is microbial rennet derived from?
a mold called Rhizomucor miehei
what is the advantage of using fermentation produced chymosin?
- absence of pepsin increases yield
- can have halal, kosher, of vegetarian status
what are the types of rennet?
- animal rennet
- microbial (vegetarian) rennet
- fermentation produced chymosin
- chy-max
- vegetable or thistle rennet
what enzymes are present in thistle rennet?
- cyprosin and cardosin (from cardoon)
- stinging nettle (from urtica)
- papain (from papaya)
- bromelin (from pineapple)
- ficin (from fig trees)
why would a cheesemaker choose to use gaots milk for cheese coagulated with thistle rennet?
interaction between the rennet and the protein chains in cows milk tends to create excessive bitterness
what are the 6 major functions of salt in cheesemaking?
- moisture control
- rind formation
- lactic acid production
- texture development
- microbiological control
- flavor development
how does salt help with moisture control?
it binds to the water in the curd
how does salt help with rind formation?
surface of cheese dries out and forms a rind
important for surface ripened cheeses (brie and camembert)
how does salt help with lactic acid production?
momentarily halts the work of starter cultures, slowing fermentation
how does salt help with texture development?
water trapped in the curd diffuses into the casein, resulting in a change from moist curd to a drier, more mellow curd
how does salt help with microbial control?
higher moisture content means higher risk for contamination
how does salt help with flavor enhancement?
allows the right activity to happen that leads to flavor an aroma compounds to be released
what ways do cheesemakers use salt?
- dry salting before pressing
- dry salting after pressing (rind application)
- brine soaked
- brine preserved
why would a cheesemaker dry salt the curds before pressing?
- it creates a brine with the moisture in the curd then is absorbed
- used for cheddar and blues
why would a cheesemaker dry salt a cheese after pressing?
rind formation
why would a cheesemaker brine soak their cheese?
- the salt draws out and replaces the why left over in the cheese
- used for gouda and havarti
why would a cheesemaker use brine preservation?
- using a salt brine of 16% keeps the cheese moist without loosing flavor
- preserves with microbiological control
- used for feta and halloumi
what forms of salt are used in cheesemaking?
- sea salt: naturally occuring, high mineral count
- potassium chloride: chemical substitute for NaCl
why would a cheesemaker add lipases to their cheese?
the lipase naturally found in milk have been damaged or deactivated by pasteurization
what are the types of lipase?
- calf lipase
- kid lipase
- lamb lipase
- microbial lipase
what flavors/aromas would you expect from a cheese made with calf lipase?
- delicate and piquant flavor
- pleasant butter scent, slightly spicy
what flavors/aromas would you expect from a cheese made with kid lipase?
- strong, sharp, or piquant flavors
- a well perceivable and persistent scent, slightly spicy
what flavors/aromas would you expect from a cheese made with lamb lipase?
- strong and marked traditional flavor like in pecorino romano, spicy
- good persistent scent
why would a cheesemaker add calcium chloride (CaCl) to their cheese?
acts as a strengthener during the coagulation step
the legal limit is 0.02%
what are some common pathogenic microorganisms related to dairy?
E. coli, Salmonella, Staphylococcus aureus, Listeria monocytogenes
what organism is used to measure pasteurization?
C. burnetii
what are some unintended effects of pasteurization?
- increases acidity
- causes precipitation of calcium phosphate
- denatures proteins
- causes changes to casein micelle
