Recently, a customer was asking us about the composition of one of the Aleppo soaps that we stock in our eBoutique Savons d’ailleurs: The ingredients listed on the label of the soap were all chemicals - not very natural sounding! Why weren’t olive oil and laurel oil listed, since they are supposed to be the main ingredients of this traditional Syrian soap?
To understand how to read a label, it is important to know what is soap…
The soap that we use for cleansing is obtained by combining vegetable or animal oils and fats with a strong alkaline solution. Fats and oils are triglycerides: a triglyceride is an ester (a chemical compound) composed of three molecules of fatty acids attached to a single molecule of glycerol (glycerine). Mixing the fats or oils with an alkaline solution causes a chemical reaction known as saponification. The water in the alkaline solution provides the medium in which this reaction occurs. In saponification, the fats are first hydrolysed into free fatty acids. During this process, the glycerol (glycerine) is released. The alkali then combines with the fatty acids, converting them to salts. These salts are what we know as soap – in chemical terms, a soap is a salt of a fatty acid. The released glycerine is left unchanged, and mixes with the saponified salts to enhance the creamy texture of the resultant product. Glycerine can also be washed out (such as in Marseille Soap) and recovered as a useful byproduct.
The predominant fatty acids in olive oil triglycerides are:
Oleic Acid - a monounsaturated omega-9 fatty acid that makes up 55% to 83% of olive oil.
Linoleic Acid - a polyunsaturated omega-6 fatty acid that makes up 3.5% to 21% of olive oil.
Palmitic Acid - a saturated fatty acid that makes up 7.5% to 20% of olive oil.
Stearic Acid - a saturated fatty acid that makes up 0.5% to 5% of olive oil.
Linolenic Acid - a polyunsaturated omega-3 fatty acid that makes up 0% to 1.5% of olive oil.
The fatty acid composition of olive oil varies widely depending on the cultivar, maturity of the fruit, altitude, climate and several other factors. The most common triglyceride component in olive oil is the oleic-oleic-oleic (OOO) triacylglycerol, followed, in order of occurrence, by palmitic-oleic-oleic (POO), then oleic-oleic-linoleic (OOL), then palmitic-oleic-linoleic (POL) - as per our example below - then stearic-oleic-oleic (SOO), and so on…
The ingredients listed on a label may either reflect the starting ingredients (e.g. vegetable oils, alkali, water), or they may reflect the results of the chemical reaction (saponification) of the ingredients after they are added together (e.g. Sodium oleate, linoleate, palmitate, laurate, aqua). From the consumer's point of view, the first list of ingredients appears more natural than the second list, but both accurately describe the same product.
The second list of ingredients is compliant with the INCI system (International Nomenclature of Cosmetic Ingredients), which was established in the early 1970s. It is a standardised system of uniform scientific names for waxes, oils, pigments, chemicals and other ingredients of soaps, cosmetics, and the like.
To illustrate this, let’s take Tadé Pain de Cendre - Ash-Based Aleppo Soap, one of the mildest 100% natural soaps to be found. This pure soap is made from olive oil, laurel oil, wood (salicornia) ash, and water, which are the traditional four ingredients of the genuine Aleppo Soap.
Wood ash is an alkali that was widely used in Syria until the 18th Century when soap-makers replaced it with mineral soda, a less expensive form of alkali. We usually associate ashes with dirt, but wood ashes are not simply dirt. The major components of wood ashes are potassium carbonate (potash) and sodium carbonate (soda ash). Potassium carbonate (potash) is used in the production of soap. Potash was man's first 'base' (basic, as opposed to acidic). We also refer to a base as an alkali. The word ‘alkali’ is derived from Arabic al qalīy, meaning the calcined ashes referring to the original source of alkaline substances. The name potash derives from ‘pot ash’, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era. Plant potash lent the name to the element potassium, and also gave potassium its chemical symbol K (from German Kalium), which ultimately derives from alkali.
In this ash-based soap, wood ash from the salicornia plant is used to create the alkaline solution that will allow saponification when mixed with the vegetable oils (olive and laurel). The ‘sodium’ in the ingredients is the end result of this chemical reaction.
In accordance with the INCI system, the ingredients listed on the packaging (Sodium Oleate, linoleate, Palmitate, and Laurate, aqua) reflect the result of the saponification. Sodium Oleate, Linoleate and Palmitate are the saponified fatty acids (or salts) of the Olive Oil; Sodium Laurate is a saponified fatty acid (or salt) of the Laurel Oil.
Fats => Fatty Acids => Salts
Olive Oil Oleic acid Sodium Oleate
Linoleic acid Sodium Linoleate
Palmitic acid Sodium Palmitate
Laurel Oil Lauric acid* Sodium Laurate
(*: Lauric acid, as a component of triglycerides, comprises about half of the fatty acid content in laurel oil.)
The properties of these fatty acids in Tadé Pain de Cendre - Ash-Based Aleppo Soap are:
Oleic acid - Conditioning, slippery feel, stingy lather, kind to skin.
Linoleic Acid - Conditioning, silky feel.
Palmitic acid - Hard bar, cleansing, stable lather.
Lauric acid - Claimed to have antimicrobial properties.