Ask A Scientist© General Science Archive

name         Emily
status       student
age          16

Question -   What is the process of homogenization?  Why is it used
for milk?

Milk contains little globs of fat which rise to the surface as what we
call cream.  Homogenization breaks these little globs of fat into very tiny
globs which are so small that the force making them rise to the top
doesn't overwhelm random bumps and swirls from the milk around them.

People do this because they got tired of having to stir milk before pouring
it from one container into another.

Tim Mooney
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Homogenization is a more specific term for a general process called
emulsification. In emulsification a discontinuous phase [gas,liquid, or
solid] that is insoluble in a continuous phase also [gas, liquid or solid],
is dispersed by some form of mechanical energy [typically high speed
stirring, or even ultrasonic waves]. Various "emulsifying agents" or
"surfactants" are formulated to stabilize the emulsion either
electrostatically or stearically.  As you can begin to see this is a whole
vast technology used in science and industry. You can find texts or
encyclopedia references by searching the term(s) EMULSION, or
EMULSIFICATION.

A few examples of emulsions of various substances are of course milk - even
fat-free milk, smoke, water borne paints, inks, foams of all sorts, and on
and on.

Vince Calder
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It is to prevent the fat from searating and floating to the top of the
bottle...of course this would be applicable only to whole milk and NOT low
or non-fat milk.

pf
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