If you
thought that transparent glycerin soap is always melt & pour and
can’t be made at home from scratch, you’re wrong. You can certainly make
it, and this tutorial is about how to do it. Why take the trouble? Well,
transparent soap looks very cool and can also be used for special
effects in “normal” CP or HP soap. And this without the chemicals there
are in M&P, when making it yourself, you definitely know what goes
in it!
Making transparent glycerin soap is something
for the more experienced soaper but really fun and worth the try. If you
don’t have any hot process experience yet you should really try that
first, as that is needed for the first steps of making transparent bar
soap. You can find a tutorial here and links to others over here.
Recipe
Not all oils can be used for making a
transparent soap, so you will have to make a special recipe for the
occasion. From soapmaking-101 I got the following list about the clarity
of soap from several oils. This was concluded from tests in liquid soap,
but I believe this also applies to making clear glycerin soap:
- Castor oil:
thick
lather, mild and makes a very clear
- Olive oil: close,
persistent lather, mild and makes a clear soap
- Almond:
Close, persistent lather,
very mild and makes a clear soap
- Apricot kernel:
medium lather, very mild and makes a clear soap
- Avocado:
dense lather, mild and makes a clear soap
- Canola:
Medium lather,
mild and makes a clear soap
- Coconut: foamy bubbles, harsh and also makes a
clear soap
- Palm: lasting bubbles, very mild but makes a cloudy
soap
- Palm kernel: large bubbles, harsh and makes a clear soap
- Tallow: lasting thick bubbles,
very mild and makes a very cloudy soap
Stearic acid also makes a clear soap
and helps to harden up when the rest of the oils chosen are rather soft.
Stearic acid does have the tendency to hasten trace, for this reason
melt it separately and add it at medium trace. Don’t use it at more then
about 3.5% of your oils since it can cause “drag” like beeswax can have
when used in soap. Other oils my possibly also give transparent soap,
just haven't found information on them.
When making
transparent soap only a very small lye discount is taken since excess
oils make cloudier soap. Take a lye discount of approx. 1 %. Besides
oils, water and lye a few other ingredients are needed to make this type
of soap. Once the soap is cooked ready, it is made transparent by
dissolving it in alcohol and adding a sugar-glycerin mixture later on.
You could also dissolve soap scraps and leftovers this same way, but
because of the superfatting issue this soap won’t be as clear as soap
made from scratch with a special recipe. Could make nice effects when
used with “normal” CP or HP soap though.
How much alcohol?
After doing some
calculations with recipes and instructions from the web, I found that
most people use a 97% strength ethanol solution between 30 and 35% of
the amount of oils. To be at the save side I suggest you go for the 35%
amount to be sure you get the soap completely dissolved. If you can’t
find a 97% strength alcohol solution you will have to recalculate the
amount of water used to make the soap. The more water in the soap, the
less clear the soap will be. Say you can find 70% alcohol (very strong
vodka or something), this is how to recalculate the amount of water to
use:
In a recipe
calling for 1050 g oils and 300 g water, you would need 35% of 1050 =
(1050 / 100) x 35 = 367.5 g of 97% alcohol. In that amount there is
(367.5 / 100) x 97 = 356.5 g pure alcohol. To get that amount of pure
alcohol with a 70% alcohol solution, you would need (356.5 / 70) x 100 =
510 g of the solution. This is 510 – 367.5 = 142 g more liquid then in
the original recipe. To balance it out you would have to subtract 142 g
from the amount of water used to mix the lye with, making it 158 g. Make
sure though that the amount of water used is at least 1,2 times the
amount of lye or it won’t dissolve completely and you will have trouble
completing the saponification process in what begins as basic HP.
When using lower
strengths of alcohol solutions you will be venturing into the realm of
water discounting, so be extra careful with the (stronger) lye solution.
To avoid this trouble and make this a bit easier for yourself work with
the strongest alcohol solution you can possibly find.
Sugar & glycerin
At certain point
you will add a sugar solution and glycerin to the soap. That makes that
transparent glycerin soap is actually only partially soap. The glycerin
makes sure the soap is still soft for the skin even though only a tiny
amount of lye discount / superfatting is used.
Again from
comparison of recipes available on the web I deducted that sugar should
be used at a weight of approx. 28% of the amount of oils. Make a sugar
solution by adding just enough hot water to the sugar as is needed to
completely dissolve it. Glycerin at 15 % of the amount of oils should do
the trick.
In short:
Your recipe
should consist of:
- Oils (choose from Castor, Almond, Apricot kernel,
Avocado, Canola, Coconut, Palm kernel oil and stearic acid (not more
then 3.5%) for a clear soap)
- 97 % alcohol at 35 % of the amount of oils (or
recalculated amount for a weaker alcohol solution)
- Water according to calculator (minus amount to balance
out a weaker alcohol solution then 97 %, total amount to be at least 1.2
times the amount of lye)
- Lye for a 1 % lye discount
- Glycerin at 15 % of the amount of oils
- Sugar at 28 % of the amount of oils, dissolved in as
little hot water as possible.
And of course
the usual soaping stuff like protective gear, pots &tools, molds,
fragrances and coloring.
For the process,
please go to page 2 of this
tutorial!