Why Milk Is White

Milk is about 87% water mixed with proteins and fats. Specifically, milk is about 5% lactose, 4% fats, and 3% proteins, according to livescience.com. As you might guess, certain fats and proteins in milk appear white – especially the casein protein. If you remember back to your elementary school science class, we perceive that an object is white when all of the colors in the visible spectrum are being reflected in our eyes. Since most milk we buy in stores has been homogenized, the fat and protein particles are evenly distributed, making the entire bottle (glass, jug, etc.,) of milk white.