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Soap Naturally Description and fatty acid properties of some soap making oils


In the simplest sense, oils that are solid at room temperature are "hard" and oils
that are liquid at room temp are "soft". Oils that are "hard",
contribute to hardness and/or lather in soaps, oils that are "soft"
contribute to conditioning. The problem is, there are degrees of soft
and hard, depending on the makeup of the individual oil.... some "hard
oils" are harder then others, and some "soft" oils are softer then
others.
One of the simplest ways to "guessitmate" how soft or hard an oil will
be is to look at one of the oil properties spreadsheets, like the ones
on Kathy Millers website.
Look at the "Iodine Value" for each oil. This number is actually a test
result, indicating the degree of saturation of an oil. The lower the
number, the more saturated the oil is. The more saturated it is, the
harder it is in soap. Oils with high numbers will be soft in soap, the
higher the number, the softer they will be.
Just a little more detail, ....
Oils are made up mainly of a variety of fatty acids. (Mostly chains of
12 to 18
carbon atoms with assorted attachments.) Some fatty acids are
saturated
(carbon atoms along the chain are holding all the hydrogen atoms they
possibly can),
these contribute hardness or lather when they are saponified.
Some fatty acids are unsaturated (have 1 or more bonds where carbons are
holding
2 hands instead of extra hydrogens), these contribute conditioning and
softness.
The main conditioning fatty acids are oleic, (1 unsaturated bond),
linoleic (2 unsaturated bonds)
and linolenic (3 unsaturated bonds). The more unsaturated bonds, the
better the conditioning, and the more easily it is absorbed by the
skin, but the softer the oil is in soap, and the more prone to
oxidation.
Because each oil is a unique combination of these fatty acids, the
properties and hardness of each will vary. Making soap means choosing a
combination of oils with different degrees of hard/soft, conditioning,
and lather, to get the particular product that fits you best.
Mary Anne
Oils, butters and fats are made up mainly of fatty acids. These react
with lye to saponify. Some oils also contain substances which are
unsaponifiable. These are things in the oil or butter, that are not fatty
acids, and, being chemically different, can't saponify. Generally they are
things like phenols, tocopherols, triterpenes, steroids, sterols, and
hydrocarbons like squalene and alcohols.. which are natural in the plants and
come out with the fatty acids in the processing of the oil.
Most oils have fairly low levels of these unsaponifiable components, others have
a fairly significant amount which affect the feel of the soap.
The following table summarises information about the amount of unsaponifiables I have collected along the years.
| Oil name | % of unsaponifiables |
|---|
| Apricot Kernel | 0.5-0.7% |
| Avocado | 2-11% |
| Black Currant | <4% |
| Borage | 1-2% |
| Castor | 0.5-1.0% |
| Cocoabutter | <0.8% |
| Coconut | 0.6-1.5% |
| Corn | 1-2% |
| Evening Primrose | 1-2% |
| Flax (Linseed) | 0.5-1% |
| Grapeseed | 0.8-1.5% |
| Hemp | 0.1-0.5% |
| Illipe Butter | 0.1-1.2% |
| Jojoba | <=50% |
| Kokum | 0.2-1% |
| Laurel Berry Oil | 1-6% |
| Mango | <=0.7% |
| Meadowfoam Oil | 0.20% |
| Sal Butter | <=0.6-2.2% |
| Sesame | 1.5% max |
| Shea | up to 6% - 17% |
Mary Anne
Each skin seems to "feel" oils differently, so opinions
vary....and experimenting yourself is really the most accurate
indicator of how oils will feel to you. Here is my 2 cents worth on the oils I
prefer to use:
Properties of Oils:
- Bees Wax: inhibits lather at higher amounts, I like about 3%
when I use it (not often), may prevent ash problems,.... if its
the natural, unrefined wax, it seems to give soap more of a
"honey" scent then honey does....
- Castor Oil: promotes lather, and conditioning, gives a thick,
small bubble creamy lather, as opposed to coconut and PK's
thinner "big bubble" lather, "soft" oil
- Cocoa Butter: I don't find cocoa butter drying, but its also
not conditioning for me, although some skins think it is....
its fatty acid profile is very similar to tallow, and to me,
that is what it feels like in soap... its mild, makes hard
soap, but doesn't help noticeably with conditioning... when I
use it in soap, I sub it for one of the hard oils,
tallow/lard/palm, and I use it because of the scent...at 15% it
leaves a light cocoa scent that enhances fo's like
raspberry,....
- Coconut Oil: hard bar, big bubble lather.... needs to be
properly balanced by conditioning oils because it does such a
good job of cleaning that it can feel drying. .... when used
with "filler oils" .... oils that are only moderate in
conditioning, I keep it at a max of 20-25% with my usual
superfat level (6%) , OR use it higher and boost the superfat
level by about 2% over my usual... when used with only "high
conditioning" oils, like my basic olive, coconut, sunflower,
castor, I use it up to about 32-36% with 6-7% superfatting.
- JoJoba Oil: is really a wax,... and very like the skins natural
sebum, ,... because of its stability (its mostly waxes and
unsaponifiables, with only 12% fatty acids), it can be used as
a superfatting oil added at the end of HP or in rebatch with no
problems...and even a very small amount 1-2% will give a very
noticeable difference in feel
- Olive Oil: mild, small bubbles, by itself it will make quite a
hard bar, but it doesn't have enough "hardening ability" to
balance softer oils.
- Palm Oil: I don't use much because of its high cost here...
there are oils that harden better, and oils that condition
better,... for me it is an expensive filler oil.
- Shea Butter: I like shea in lotions, but not soap... for me it
needs to be treated like cocoa butter in soap.
- Tallow: hard bar, small thin lather.... my preference to
replace palm in recipes
- Sunflower, Safflower, Grapeseed, Hemp, - I like a bit of a
high linoleic oil in all my soaps, 10-15% of one of these in
every soap. In soaps, these oils feel much better on my skin
then even shea or emu. If the level is kept in this range, I
don't have a problem with spoiling,... although the hotter and
more humid your climate, the more apt you are to have a problem
with polyunsaturated oils.
Mary Anne
Fatty Acid profile of high oleic Sunflower oil, as compiled by listmember Mary Anne
The regular is cheap, in 3 or 4 L containers, and just labelled sunflower
oil. The high oleic sunflower, is labelled "monounsaturated" sunflower,
and pushed as a heart healthier (is that a word?) alternative. Cost
wise, it is similar to cheap grades of olive, one litre of high oleic is
about the same as 3 litres of regular sunflower.
It should be more like olive.
Here are the spreadsheet values:
| Fatty acid name | reg. sunflower | high oleic sunflower | olive |
|---|
| linoleic | 70% | 4% | 5-15% |
| oleic | 16% | 83% | 63-81% |
| palmitic | 7% | 3% | 7-14% |
| stearic | 4% | 4% | 3-5% |
| iodine value | 119-138 | 83 | 79-95 |
If "biodynamic sunflower" means the hybrid high oleic sunflower, then an all sunflower would be pretty much the same as an all olive. One of the batches I did with the coconut milk powder was 64% high oleic sunflower. As far as how it feels and behaves, you can't tell it from the same recipe done with olive. High oleic is very different in fatty acid profile & iodine value from regular sunflower, its really very similar to olive.
Website links: -
These sites are US producers and have some info on high oleic sunflower
and high oleic safflower.
Mary Anne
Most (if not all) sunflower oil commonly available in Australia is of the high-oleic type. For those who would like to maintain an "Aussie flavour" in their soaps, sunflower oil is a good choice, because most of what is on offer is Australian grown and Australian made.
- Peerless: manufacturer of Australian high-oleic sunflower oil.
Marina, ListMum
Fatty Acid profile of Peach kernel oil, as compiled by listmember Mary Anne
| Fatty acid name | value |
|---|
| linoleic | 15-35% |
| oleic | 55-75% |
| palmitic | 5-8% |
| SAP value | .137 (NaOH) |
| iodine value | 108-118 |
From the fatty acid profile it should be very similar to apricot kernel. It's really a very conditioning oil, soft, with little lather, quite unlike palm kernel.
Mary Anne
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