Cheese Cultures Essays

Submitted By elliemaggie
Words: 1221
Pages: 5

Cheese Cultures The purpose of a cheese culture is to increase the acidity in the milk which then helps the rennet set. It also helps preserve the cheese and adds flavor during the aging process. Milk is a perfect medium for good and bad bacteria. The culture inoculates the milk with the good type of bacteria which multiply by consuming the lactose (milk sugar) in the milk. The result raises the acidity and once the good bacteria have taken hold in the milk, then this helps prevent the bad bacteria from gaining a foothold. Cultures can be broken into two types. Mesophilic and Thermophilic. Choosing either a Thermophilic or Mesophilic will depend on the type of cheese that you are going to make. 1. Mesophilic is a non-heat loving culture and is used for making cheeses that are not heated to more than 102 degrees. This is the most common and is used to make 90% of the cheese varieties. This would include Soft cheese, Chevre, Blue Cheese, Feta, Cottage cheese, Farmers cheese, Colby, Cheddar, Camembert, Brie, Cultured Buttermilk, Sour Cream and many others. 2. Thermophilic is a heat loving culture and is used to make cheeses that can be heated up to 130 degrees. This is most common in Italian cheeses such as parmesan, provolone, mozzarella and Swiss, Monterey jack, and a few others. Yogurt is also made using a thermophilic culture.
Many varieties of these two bacteria culture types are available with names such as flora dancia, lactoccus bulgarius etc. No matter what types of fancy names are used in a specific culture it will still fall into one of the two types of culture. This simply means that they can have different strains of bacteria which can produce slight differences in taste. No matter what it’s called, Mesophilic will always be a Mesophilic and the same is true of the Thermophilic.
DVI stands for direct vat inoculant; this is added directly to the milk, usually at a rate of 1/8 teaspoon of dry culture for each gallon of milk used. The freeze dried packet can be kept in the freezer for several months. DVI is very handy for the average home cheese maker who is not making cheese on a daily basis. DVI is more convenient and produces more consistent results compared to Mother culture process (this is not being used and is not important in this experiment). Even large cheese making plants now uses DVI to ensure that every batch produces a uniform product.
About the milk:
Milk contains proteins, specifically caseins, that maintain its liquid form. Proteases are enzymes that are added to milk during cheese production, to hydrolyze caseins, specifically kappa casein, which stabilizes formation preventing coagulation. Rennet and rennin are general terms for any enzyme used to coagulate milk. Rennet is also the term for the lining of a calf's fourth stomach. The most common enzyme isolated from rennet is chymosin. Chymosin can also be obtained from several other animals, microbial or vegetable sources, but indigenous microbial chymosin (from fungi or bacteria) is ineffective for making cheddar and other hard cheeses. “The limited supplies of calf rennet (from the stomach) have prompted genetic engineering of microbial chymosin by cloning calf prochymosin genes into bacteria. Bioengineered chymosin may be involved in production of up to 70% of cheese products. While use of bioengineered enzymes spares the lives of calves, it presents ethics issues for those opposed to eating foods prepared with GEMs (1)”. That is why raw organic milk will only be used in this experiment so that no other variables will be presented at time.
Milk contains a number of different types of proteins, in addition to the caseins. Cow milk also contains whey proteins such as lactalbumin and lactoglobulin. The denaturing of these whey proteins, using proteases, results in a creamier yogurt product. Destruction of whey proteins is also essential for cheese production.
During production of soft cheeses, whey is separated