15: milk milk milk two

haven't been posting much...too much homework/ tests and procrastinating. TT"

i've been researching a bit more on foaming milk and etc. milk is commonly foamed or frothed as an addition to certain coffees and beverages.
the process used to froth milk for use in coffee is different to my method for this experiment. to froth milk, a "steam wand" forces steam into the milk and forms tiny bubbles. the milk is heated during the process and the heat can affect how well milk foams.
when you steam milk (which is what frothing milk with steam is called), the proteins in the milk is the most important element in creating the tiny bubbles of air.

When you are steaming milk you are incorporating air into the milk. Proteins are
important because they are adsorbed* by the thin film surrounding an air bubble
giving stability to the entrapped air.

*adsorb: to gather (a gas, liquid or dissolved substance) on a surface in a condensed layer [http://dictionary.reference.com/browse/adsorb]

the stability of milk foam can vary depending on the milk's fat content. at around 5% (including whole milk), foam stability is at its lowest, meaning that as the fat content increases or decreases from 5% the foam becomes more stable.
foam volume is similar to foam stability as it is at its lowest when milk contains around 5% fat (including whole milk). skim milk supposedly has the greatest potential to produce a high volume and stable foam since it contains hardly any fat. as the fat content of milk increases from around 5%, the milk's ability to produce a foam with high volume and stability also increases.
because these observations are based on steaming milk, i am not sure whether they still apply to just shaking small quantities of milk vigorously for a short period of time. in theory, whole milk is the worst choice for producing a foam with a large volume.
it is said that low fat milk takes on the most air at lower temperatures, but this also applies to whole milk and cream (although "to a lesser extent"). however, all milk, no matter of its fat content, produces the greater volume of foam at cooler temperatures (when compared to the foam production at higher temperatures). milk at room temperature also does not foam well (and it'll probably have gone off by then). therefore, cold milk (preferably straight out of the fridge) presumably gives the best foam.
[http://coffeegeek.com/guides/frothingguide/milk] <--really awesome source [http://coffeeinfo.wordpress.com/foaming-milk-without-steam/]

the coffeegeek website above also details two different types of protein found in milk that contribute to the formation of the bubbles in the foam of milk. i will probably discuss this later on, mainly for the research and to publish more posts. as most of the research from above has come mainly from the one website, i'll need to look for more sources to verify that the information i have above is accurate. :)

i also wanted to say that i've almost finished making my totally awesome test tube rack, using scrap pieces of cardboard, my chocolate crunchie box and the lid of a shoebox. just need to finish off the base.
i hope to start my experiment VERY VERY soon, since the report is due in 3 weeks (how depressing). the experiment will hopefully take no longer than a week because i'll probably need 2 weeks to analyse my results and perfect my science report.