13: milk milk milk one

i'm going to be starting some research on milk (from cows) to see if using different milks for my test liquids is a good idea.

milk is an opaque white liquid produced by the mammary glands of mammals. milk for human consumption often comes from cattle, sheep and goats. cow's milk is the most commonly consumed form of milk & is often processed into other dairy products such as cheese, cream, butter, yoghurt and ice cream. [http://en.wikipedia.org/wiki/Milk]
milk for consumption often goes through different processes before going on sale on supermarket shelves, such as pasteurisation and homogenisation.
pasteurisation is the process used to partially sterilise milk, resulting in extended shelf life. milk is heated to 72°C for at least 15 seconds and then cooled immediately. this destroys any harmful bacteria and micro-organisms.
homogenisation is a process used to prevent the cream in milk separating and rising to the surface. the process consists of passing the milk (under pressure) through very fine nozzles, allowing the fat globules to evenly disperse throughout the milk and thus creating a smooth, creamy texture and taste. [http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk.aspx]
milk can be separated into groups depending on what and how much of something it contains, such as fat.
regular or whole milk is milk that (usually) has nothing added or removed. it contains on average 3.8% fat and no less than 3.2%. this type of milk is both pasteurised and homogenised and has a rich creamy texture.
reduced fat milk has approximately 2% milk fat and could have added protein and calcium.
low fat milk has less than 1.5% milk fat and usually extra calcium added.
skim milk has less than 0.15% milk fat with extra milk solids added for taste. it has a more watery appearance compared to other milks and a less creamy taste.
evaporated of unsweetened condensed milk is a type of concentrated milk. the total number of milk solids is increased to 28% by the gentle evaporation of water. the milk is sterilized after being canned to eliminate harmful micro-organisms and to ensure a long shelf life. skim evaporated milk contains around 20% milk solids.
powdered milk is "an evaporated pasteurised milk concentrate, containing about 40% milk solids". it is dried to reduce the moisture content to about 3%.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Milk/Types-of-Milk.aspx#]
[http://www.milk.co.uk/page.aspx?intPageID=43]
cream is the fat component of milk and contains around 48% milk fat in its natural state. it is the removed component of milk to make skim milk.
[http://www.dairyaustralia.com.au/Products-and-Recipes/Dairy-Products/Cream.aspx]

okay, i think that's enough research for now...as you can see, for all of these types of milk (& including the cream), i've mentioned the substances fat content. i'm hoping to use this to form my hypothesis. so far, i reckon that one of the thicker liquids such as evaporated milk might produce the best foam, based on the foam's volume and longevity. this still needs more research though, so i'll see. i'm not sure if i'll include the cream as a test liquid because it's not technically milk.
by the way, milk fat is "the fatty portion of milk" [http://en.wikipedia.org/wiki/Butterfat] and milk solids are "combined yield of fat and protein in the milk" [http://medical-dictionary.thefreedictionary.com/Milk+solids]. i'm hoping that knowing amount of milk solids instead of milk fat in some of the substances might not affect the order of least to most amount of fat content...i might ask ms zhang...

i'll hopefully start my experiment VERY soon, hopefully before week 6. good luck to everybody starting their experiment. :)