›› Lye Soap
Where would we be
today with out soap? The simple commodity we use everyday to
clean our bodies, our hair, our clothes, our cars, our dishes and more,
is something we tend to take for granted. Have you ever
wondered what it is exactly, and how it works? Who discovered
soap, and how long have we been using it?
Soap is the word we use to describe a number of different compounds
that all basically act in the same way. They are all cleaning
compounds that function by a chemical process called
‘emulsification’.
Fats, oils, and greases are very difficult to clean using just water
since these substances don’t mix well with the
liquid. Soaps are all chemically significant because they mix
well with both water and fat based compounds. A portion of
any soap chemical is ‘hydrophilic’, or
‘water loving’, and allows it to dissolve freely in
water. The other half of soap compounds, however, is
‘hydrophobic’. This part of the soap
allows it to mix with fats and oils, since they are also
hydrophobic. Most soaps today use a formula involving lye, a
caustic solution of potassium hydroxide, and are commonly called
‘lye soaps’.
When water with soap dissolved in it comes in contact with a fat based
compound, the hydrophobic portion of the soap molecule attaches to the
fat. The fat soon becomes completely covered in soap
molecules and then breaks apart due to the soaps mutual attraction to
the water molecules flowing around it. On a side note, this
emulsification process is actually the same way we digest fat that we
eat, with the liver made substance ‘bile’ acting as
the ‘soap’. Bacteria, dirt, and other undesirable
contaminants to our skin tend to get trapped in layers of oil than
won’t readily come off with out using soap.
There are records of soap use that date as far back as ancient Babylon
in the third millennium BC. Strangely, the Romans were not
known to use soap. Though the word ‘soap’
first appears in a text written by the famous Roman scholar
‘Pliny the Elder’, he refers to it as a kind of
ancient hair gel in use in some regions of the time, not for its
detergent qualities.
Lye soap of the kind we know today was invented by the Arabs well after
the fall of the Roman empire, in either the 6th or 7th centuries
AD. The formula is the same basic formula we still use
today. Generally, lye soaps are made by mixing animal fats
with lye. Because lye is such a caustic chemical, this can be
a dangerous process, but the resulting lye soap is of course
harmless. Several alternative fats can be used to make a lye
soap, many people make their own soaps at home using olive
oil. Soap made with olive oil is sometimes called Castile
soap, after the region of Spain in which it first became popular.
Whether washing your hands, taking a shower or doing your dishes, lye
soap is an extremely useful tool in keeping good hygiene. I
don’t even want to imagine what people smelled like back in
times when it wasn’t known or used.
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A Healthy Dose of Good Advice
