Measure 10 ml of milk testing sulphuric acid into a bytyrometer for milk, making sure to choose the butyrometer specific for the particular type of milk being analysed(whole milk, skin milk). Deliver from a pipette 10.94 ml of the milk down the side of the butyrometer so as not to mix with the acid. in this and subsequent operations, care must be taken not to wet the neck of the butyrometer. Add 1 ml of amyl alcohol. Insert the stopper using the plunger and thoroughly mix the contents of the tube either by using the stand provided or by hand after first wrapping the tube in a cloth. Place the tube in water at temp 65 and allow it to attain this temperature. Centrifuge at 1100 rpm for 4 min. Immerse the butyrometer, stem upwards, in a water bath at temp 65 until adjusted to this temperature. Read off the percentage of fat from the graduations on the stem by adjusting the separating line to a convenient point(by manipulation of the stopper using the plunger) and reading the position of the bottom of the upper meniscus. Carry out each determination in triplicate and obtain a mean value