milk

According to Dictionary.com, milk is "an opaque white or bluish-white liquid secreted by the mammary glands of female mammals, serving for the nourishment of their young." It is sterile when secreted in the udder of a healthy cow (we’re talking about cow milk). It is loaded with nutrients...

Have you noticed how milk processors and brokers will buy milk by weight from farmers (they use weighing machines to determine the quantity they will pay for) and then sell the same milk after processing/value addition to the final consumer by volume? Here is the reason why this makes sense...