Calvin Sambrook coughed up some electrons that declared:


Despite having an "O" level (sort of like a good GCSE for any youths here)
in Chemistry I was in fact that kid mucking about at the back of the class
so I now have to admit to not really knowing what soap is made from and
how
(hangs head in shame). Anyone care to tell me?

IIRC, strong alkali and fat/oil, eg: caustic soda + veggie oil = soap +
glycerine

That's why cheap crap crude soaps don't do your skin any favours as they are
pH7 due to residual alkali.

Animal fat can be used too.

Human fat could also be used (cf Fight Club)

I expect in the old days, it was made from a.n.-other-random-fat and lye
(from wood ash) but I'm guessing. I know lye was a popular alkali as
everyone had loads of wood ash going spare.

Here's an interesting article:

http://www.history-science-technology.com/Notes/Notes 5.htm

"Fish oil soap" - erk! Wouldn't wash with that and expect to pot the red
that night.

But I really *didn't* know grease involved soap. I thought it was just
various fractions of distilled crap. Learn something every day...

Cheers

Tim