Sorry for the delay in posting. Life gets in the way of all of our best intentions!
In my last post I talked about what soap is: Lye + Oil = Soap
I’m not going to spend time discussing the myriad of options for oils to use in soap, and the properties each brings to the party. This has already been done extensively, and far better than I could! Here is a link to one fairly comprehensive but not exhaustive list:
All of these oils fall into our ‘natural’ criteria, the only issue is whether or not they are organic. This is a subject that definitely calls for its’ own post, so watch for that in the days to come.
Today I’m going to look at some of the ingredients that get added to the basic bar of handmade soap: fragrance, colour, and additives.
In order to add fragrance to soap, you have 3 options:
1) No added fragrance – this means that the scent of the soap will come from the base ingredients used to make the soap, and nothing else. If none of your ingredients are strongly scented, you will end up with an unscented bar. Examples of some scents that may survive the saponification process are honey, oatmeal, and cocoa butter. You shouldn’t expect strong fragrance from those, but there may be some, depending on the amounts used and the other ingredients in the soap.
2) Synthetic fragrance oils – These are compounds which may or may not contain essential oils as the base, mixed with various chemicals to duplicate their natural counterparts. For example rose essential oil, or absolute, requires somewhere between 4,000 and 7,000 pounds of rose petals to extract one ounce of the pure oil. Rose absolute sells for around $250 per oz, which means a single bar of soap would have to be priced at between $50 and $60 just to cover the cost of the rose absolute with no profit margin at all! So chemists analyze the essential oils to identify the individual components, then synthesize them in the lab to produce more cost efficient alternatives.
3) Essential oils – Some essential oils are very strong in the finished bar, such as peppermint, lavender and patchouli, while others, such as any of the citrus oils, may be faint and fleeting, depending on the amount used. The issue with essential oils is two-fold: how it was extracted from the plant, and whether or not it has been adulterated after extraction.
There are 3 methods of extracting essential oils from plant materials:
Steam distillation: Employs steam to convert the volatile liquid (essential oil) into a vapour , condenses the vapour back into a liquid, then separates the oil from the water (hydrosol). This is the most natural and cost effective method of producing essential oils, however the heat involved in the process means it cannot be used on fragile materials which are easily damaged by heat, such as citrus oils.
Expression: Most nut, seed and citrus oils are extracted using a “cold pressed” method, which means the oil is forced from the material under high mechanical pressure without heat. The process is natural, but cold pressed oils may contain phthalates leached from the plastic tubing used to collect the oil.
Solvent: Solvent method is used to extract oils from plant material that has a very low yield of essential oil, or contains mostly resinous components that are difficult to extract using other methods. I won’t go into a full explanation of the process, however it involves adding the plant material to a liquid and shaking vigorously to disperse the essential oil into the liquid. The most common solvent used is hexane, however it could also be benzene, petroleum ether, methanol, or ethanol. The issue with solvent extraction is that a small amount of the solvent may remain in the essential oil after the process is completed. When hexane is used, the solvent residue in the finished product is about 10 ppm (parts per million). Solvent extraction is generally used for delicate florals such as jasmine, hyacinth, narcissus, and tuberose, and for highly resinous material such as amber.
4) Botanical extracts – Some soapmakers soak or infuse plant materials into vegetable oil or water in an attempt to transfer the scent and properties of the material into their soap. Some examples of this would be citrus peel or green tea. The amount of fragrance that can be obtained from this would be very faint, as it would be highly deteriorated after exposure to both the chemical process of saponification, and the heat produced by the process.
Of these methods of fragrancing soap, the two that may not be considered natural are synthetic fragrance oils, and essential oils which are produced using the solvent method of extraction. This is why you will often see soapmakers stating that their essential oils are steam distilled, or cold pressed, or stating that their fragrance oils are phthalate free.
When it comes to natural or not, fragrance is pretty clear.
Colorants, on the other hand are a murky subject, and what is natural is very subjective. Soap colourants generally fall into the following categories:
Plant based colourants – Many plants have been used for centuries to dye wool and cloth, and these same plants are being used today to colour handmade soaps. Some examples are annatto seeds for yellow/orange, woad for blue, and spirulina for blue/green, but there are many more. The plant material is soaked in a vegetable oil base, which allows the colour to infuse into the oil, which is then strained and added to the soap as part of the base oils in the recipe. This infusion can be done with the application of low heat, or by the cold infusion method which involves leaving the oil and plant material mixture at room temperature for several weeks, or until the desired colour is achieved.
Inorganic colourants – There are 3 sub-categories which could be present in your soap, and all of them were originally mined from the earth, which is why many consider them to be “natural” as opposed to “manmade”.
Mica is defined as “A shiny silicate mineral with a layered structure, found as minute scales in granite and other rocks, or as crystals.”
If left in its’ original state, ie uncoloured, mica is a natural additive. The only thing that can be listed as mica in the INCI ingredients list of cosmetics, including soap, is the natural, uncoloured form. Every coloured mica, whether it be in eye shadow, lipstick, or soap, must list the colour separately in the ingredient list. For example, if the mica is coloured with oxides, you may see “Mica, tin oxides” in the list. If it is coloured with synthetic colourants it may appear as “Mica, FD & C3” . (FD&C is an acronym for Food, Drug and Cosmetic, and indicates the presence of a synthetic dye approved for use in those products.) This does not guarantee that the ingredient will be listed properly. Many soapmakers do not realize that mica could be coloured with synthetic colorants, or they are relying on their supplier who may not have disclosed the full ingredient list for the product.
Ultramarine is a mineral pigment which occurs naturally, however the ultramarine pigments used in cosmetics today are synthetically produced from kaolin clay, sodium sulfate, sodium carbonate, sulfur and powdered charcoal.
Oxides, including iron oxides and titanium dioxide are naturally occurring mineral deposits, however, oxides for cosmetic use have been synthetically produced in a lab for decades, due to the concern over trace amounts of heavy metals present in the mined product. Synthetic oxides are identical in chemical structure to their natural counterparts.
If you are extremely sensitive to chemical additives, you may want to stick to unscented products or those using only verified natural fragrance and colour, however, before you make that decision, consider that the amount of any additive remaining in a bar of soap is very minimal.
For example, the maximum recommended amount of fragrance oil added to handmade soap is 1 ounce per pound of oils. This translates to approximately 4.5% of the total batch, which results in approximately .2 of an ounce of fragrance oil in a bar of soap.
However, this is the amount present in the raw soap batter. This then goes through the chemical reaction known as saponification, which also subjects the additive to high temperatures, further degrading it. Then, consider that soap is a rinse off product. Our skin is designed to protect us against pathogens, such as bacteria, and prevent dehydration through water loss. What this means is that it is not easy for foreign substances, including essential oils and other botanicals to penetrate this layer. I am not saying that no penetration occurs, only that absorption through the skin is minimal even when pure essential oils are applied, therefore the amount absorbed from soap will be extremely minimal.
(The subject of how much essential oil is absorbed through the skin is hotly debated by aromatherapists, naturopaths and manufacturers of bath and body products, and deserves a separate post….look for that here in the weeks to come.)
Okay, that’s fragrance and colour, and this post is long enough, so I think we’ll leave other additives for tomorrow’s post!