14: method

aim:
to investigate which types of milk (based on their fat content) produce a good foam with high volume and longevity.

hypothesis:
more research is needed.

materials:
-safety goggles
-test tubes with rim 25mm X 150mm
-rubber stoppers without holes
-test tube rack
-measuring spoons
-300mL (approx.) of each test liquid (the different milks mentioned in the previous post)
-stopwatch
-metric ruler
-magnifying glass (optional)
-camera (optional)

method: (for one day)
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the measured test liquid into a test tube and insert the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9)* Measure and tabulate the distance between the starting level and the top of the foam.
10)* Measure and tabulate the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations and take photos if desired.

]12) At each time increment (later explained), repeat steps 9 to 11 until the trial is over (when there is no foam or when 30 minutes has passed).
13) Repeat steps 1 to 12 two times (there will be fifteen trials in total).
14) Repeat steps 1 to 13 for each type of milk.

*- use a table similar to the one shown in the post '08: approved experiment'

NOTE: this experiment will most likely be completed over five separate days and there will be fifteen trials in total for each type of milk. that is why the method only states to repeat the experiment twice for each type of milk as the method is for a single day.