Investigators say the adulteration was nothing short of a wholesale re-engineering of milk. Researchers established that workers at Sanlu and at a number of milk-collection depots were diluting milk with water; they added melamine to dupe a test for determining crude protein content.
The adulteration involved a fundamental alteration of milk's composition. Scientists discovered that employees at Sanlu and several milk-collection facilities were watering down milk by adding water; they also added melamine to deceive tests for determining crude protein levels, which is essentially a measure of the milk's nutritional value.