The Art of Soapmaking and the Chemistry Behind it
Soap making can be a rewarding form of art when the scientific reaction occurs between fatty acids and an alkalis.
The ancient Babylonians from 2800 B.C were the ones who invented soap. Their product was made from animal fats combined with wood ash and water which was used to wash wool and cotton in preparation for weaving into cloth and not necessarily to wash the body.
The Celts made soap from animal fats and plants ashes to make their soap. They named their product "Saipo" which is where the origin of the word soap was derived. Back in those centuries they didn't have calculators, scales or food grade, lab-created chemicals. They mixed together alkali into oil and hoped it turned into soap.
As we moved into the 1700s potash was made from wood ash to make soap. Fast forward into the 21st Century, commercial store soaps are made with many different man-made chemicals such as the following list of ingredients:
Methylparaben: or anything ending in "paraben" these preservatives act as estrogen in the body, affecting hormonal balances.
Fragrance: The FDA doesn't require companies to disclose the ingredients to consumers because the chemicals that produce fragrances are considered "Trade Secret". Constant exposure to fragrances can negatively impact the nervous systems and tigger allergies, migraines and asthma symptoms.
Triclosan: found in antibacterial soap creates dioxin, a carcinogen that has been found in high levels in human breast milk. Dioxin can have disruptive effects on the endocrine system and negatively affects thyroid functions. Also the primary toxic component of Agent Orange (pesticide).
Sulfates: a surfactant; foaming detergent that strips the natural oils from the skin and an endocrine disruptor. The most common one is sodium lauryl sulfate (SLS).
Tetrasodium: Ethylenediaminetetraacetic Acid, is made from formaldehyde and sodium cyanide. A water soluble ingredient used as a "chelator" which binds to certain mineral ions to inactivate them (popular preservative in medicine & cosmetic).
Diazolidinyl Urea: when this chemical breaks down in the product or on the skin, it releases formaldehyde. It's an endocrine disruptor and possible link to cancer.
Phthalates: ingredient used to produce plastic and known to cause cancer.
Petrochemicals: made from petroleum.
Synthetic Perfume: linked to allergies and hormonal issues.
Artificial Coloring: causes health problems and illnesses.
Stearic Acid: fatty substances taken from the stomach of pigs.
Cocamidopropyl Betaine: a foaming agent that cleanses the skin but may also be an allergen.
Propylene Glycol: a penetration enhancer, meaning it's a carrier for other chemicals bringing them into your skin and your bloodstream. It's found in over 3,000 products.
Tin Oxide: used to line cans for food, beverages and aerosol.
PEG-6/Dimethicone: a silicone-based polymer that creates a hydrating barrier on the skin. Could lead to breakouts and blackheads; traps impurities, prevents the skin from its normal functions, such as sweating, temperature regulating and shedding of dead skin cells.
This is just to name a few of many ingredients that are in a commercial synthetic soap. With minimal government testing on these chemicals, it becomes up to us, as smart consumers to make informed decisions as to what does and doesn't go on our skin.
Getting back to basics, there is a great demand for natural and organic plant-based ingredients. All natural bar soaps are made from sodium hydroxide, which is one of the most common bases or alkalis, also known as caustic soda or lye. In our grandparents time, the making of handmade soap was first to create ash by burning hardwood and mixing it with water to produce potash and then poured into the melted lard or tallow to form soap. We have eliminated that process in our soapmaking by purchasing sodium hydroxide and potassium hydroxide from a reputable distributor.
Sodium hydroxide (lye) is the essential ingredient to make bar soap and potassium hydroxide (lye) is the essential ingredient to make liquid soap. The chemical formula for sodium hydroxide is NaOH (sodium oxygen hydrogen), and its molar mass is 40.01g/ml, and potassium hydroxide is KOH (potassium oxygen hydrogen), and molar mass is 56.1056 g/mol. You can't make soap without lye. The other two main ingredients are water and oil.
The second ingredient is distilled water to combined with the sodium hydroxide or potassium hydroxide to create a lye-water solution. And the ultimate ingredient is fatty acids (oils), each fatty acids has an individual saponification (SAP) value that must be calculated to create a soap formula.
Saponification is when the chemical reaction between lye water solution and oil creates glycerin and soap. Glycerin is a by product of soap, a molecule of lipids-fatty acids, a humectant that draws moisture to the skin and work as a protective barrier over the skin to keep moisture in; Glycerin is a powerhouse and is taken out of commercial soaps to use in cosmetic and other products. Making soap is relatively easy process but it's also a process which should be approached with caution since the NaOH and KOH are caustic sodas.
To calculate the amount of sodium hydroxide needed to make a small batch of soap, is a simple mathematical formula. For example, the SAP value for olive oil is .135 and multiply by amount of oil needed; to find the water amount, multiply .359 x the oil need for the recipe. After finding the lye and water amount needed - it's best to discount the lye to 5% called superfat.
See the formula below:
.135 x 32 oz olive oil = 4.32 sodium hydroxide amount
.359 x 32 oz olive oil = 11.48 water amount
.184 x 12 oz coconut oil = 2.21 sodium hydroxide amount
.359 x 12 oz coconut oil = 4.31 water amount
Finding the 5% discount for the both sodium hydroxide amount needed; take the 6.53 oz x 95% = 6.20 oz.
This formula requires only four ingredients, coconut oil to make a hard lathering soap and olive oil to produce a moisturizing bar soap, the two oils are companion oils that compliment one another.
As for the art of soap making, your options are limitless with many different vegetable oils to formulate with herbs, clays and essential oils to be able to express your own unique style and preferences in creating magic with alkalis and fatty acids. Click on for a demonstration of the art and beauty of soap making.