First published on the email group for he-special.org.uk
I thought I would post the soap recipe here as there are now a lot of families doing what we have done for year, educating their children themselves. Making soap is not only a chemistry lesson, but it is usual and necessary in combating the coronavirus.
Have fun and stay safe!
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First let me say something about safety. Caustic soda burns and is not good
if you get it in your eyes, or on your skin. The books I have all say wear
eye protection, and rubber gloves.
I insist that everyone helping wear eye protection when measuring, mixing
and stirring. I don't always wear gloves myself as I know that my hands will
stand a lot of stuff (used to work as a builder with cement!) but I do wear
gloves if I am actually touching the stuff, for instance when I drop the
spoon into the mixture LOL!
So there you are. Wear eye protection and gloves, and don't sue me if you
don't and you burn yourself!
It is also very important to weight out the ingredients very, very
accurately. Right down to the last gram, so the chemical reaction is completed and
you don't end up with soap with too high a pH.
Do not use iron or aluminium as they will react with the caustic soda.
And try not to breath in the fumes when you add the caustic soda to the
water! Do it in a well ventilated place!
Ingredients:
454g lard, beef dripping, or vegetable fat
57g sodium hydroxide (caustic soda) (obtainable from ironmongers)
142g distilled or spring water (the water is to be weighted, not measured by
volume)
1 tbsp or 15g of your favourite essential oil - optional
1: measure out the fat and put in a stainless steel pan to melt. Using a
glass thermometer allow it to cool until it reaches approx. 54C.
2: weight out the caustic soda and water and pour the caustic soda into the
water (never the other way around) and stir until dissolved. Use a glass or
stainless steel container only and a glass not aluminium thermometer (many
preserving thermometers are aluminium).
Leave until the temperature is around 54C.
I find that I start the caustic soda and water when the fat is at about 60C
and they both end up at the same temp around the same time. It isn't so much
what the temp is, it is that they are the same. Anywhere between 40C and
60C will be OK.
3: Add the caustic soda solution to the fat and stir carefully. Leave to
for around 30 minutes, stirring occasionally, until 'trace' is reached. Trace
is what they call it when the mixture is thick enough to leave a line on the
surface of the mixture when you drip it off the back of a spoon. It will take
different times depending on which fat you use, vegetable taking the longest
and beef the shortest.
4: Add colouring (a bit of wax crayon) and essential oil if wished once
trace is reached but before it gets too stiff to stir!
5: Pour the mixture into a greased mould. Plastic food trays are very
good.
6: cover the soap with clingfilm and a towel or blanket to retain the heat,
and leave to cure for 24 hours.
7: Cut and turn out the soap, and recover it and leave it to cure for four
weeks.
Note on essential oils. I find that just using one is the best. That way
there is no complicated smell. This is were personal opinion is important.
Some people like lavender, some don't. I like using benzoin, and vanilla,
and cinnamon. I make soap to sell at Christmas coffee mornings that has a
fragrance called Christmas Tree which is made up by an aromatherapies. You can
make soap without anything. Lard will smell a bit, but I find that both
vegetarian fat, and beef fat pleasant enough. The thing is to experiment. The
raw ingredients are very cheep in themselves, it is only the essential oils
that put the price up.
The longer you leave the soap to cue, the harder it gets. I am using a soap
I made 1 1/2 years ago and it is hard enough that is doesn't disintegrate in
water. Commercial soap is made and sold so quickly now that it is really
soft.
Commercial soap also has the glycerine taken out of it to be sold
separately, whereas home made soap has it left in.
This is just the basics of soap. There are lots of books and web sites
about it. You can get really creative and make really complicated soaps or you
can keep it simple. We also like to make floating soap!
There are also lots of sites that talk about the chemistry of soap - the
saponification. In fact, my son calls it The Chemistry Lesson!
The book that I use the most as I feel that it explains it in the best way
is The Handmade Soap Book by Melinda Coss, ISBN 1-85368-807-x.
Happy washing!
