Contrary to what the senses in our mouths tell us, heavy cream is actually lighter than light cream, and light cream is lighter than whole milk, which is lighter than skim milk. Skeptical? As proof, consider that cream invariably rises to the top of nonhomogenized milk. This phenomenon can be easily explained because fat has a lower specific density than water. Now, consider that the fat and water percentages for heavy cream are, respectively, about 40 percent and 55 percent, whereas those for milk are, respectively, about 4 percent and 87 percent. The figures for skim milk are about 1 percent and 90 percent.
What fools our senses is primarily the fact that fat has a higher viscosity than water. Having been taught at a very early age the misleading phrases "heavy cream" and "light cream" biases our interpretations, too.
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