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The Natural Bar Soap Company Glossary

Our Soap Making Glossary is an ever-evolving work in progress, but we hope our list of soap making terms and related words will be a great resource for those wishing to learn about the ingredients in our products, soap making, soap ingredients, and soap information. Those wishing to learn to make soap should learn as much as they can about the soap ingredients they use and the soap making techniques used to make the best natural soap. If you have suggestions for other soap ingredients or soap terminology that you wish to see included in this list, please use the Contact Us link at the bottom of the page.

Additives- clay, minerals, herbal powders or dried plants added to handmade soap to provide beneficial features, such as oil absorption, exfoliation, scent, and visual interest.

Alkali- On the pH scale, alkalis exist at one extreme, while acids occupy the other. Alkalis are bases, and therefore have a pH greater than 7.0. Alkalis are soluble in water. Two commonly known alkalis are Ammonia and Sodium Hydroxide (lye). In soap making, lye is mixed with water, and then added to plant and/or animal oils in a reaction known as saponification. Sodium Hydroxide is used to created hard, bar soap, while Potassium Hydroxide is used to create liquid soaps. Alkalis feel slippery to the touch, due to their ability to saponify surface oils on the skin.

Alkanet- The powdered root of the Common Bugloss plant, Alkanna Tinctoria. A wonderful natural dye, used to impart color to cosmetics, natural soap, fabrics and food. The root, while black on the outside, contains a bluish-red flesh.

Base- The opposite of an acid. An Alkali. On the pH scale, bases are substances with a pH higher than 7.0. Lye is a strong base. The term can also be used to refer to untinted, unfragranced soap batter, and also to a pre-made solution of oils, lye and water without any other additives, used to create soap. Pre-made soap base is used by those not wishing to make soap "from scratch" with lye, in a process known as "Melt and Pour soapmaking."

Bentonite- A naturally occurring clay often used as an additive in cosmetic products. Bentonite is known for its ability to absorb 12-15 times its weight in water. Added to natural bar soap, bentonite has the ability to absorb oils and impurities from the skin. Bentonite is found in many areas worldwide, but notably, in large deposits along the east coast of the United States. The main component of bentonite is a clay mineral called montmorillonite.

Bergamot Essential Oil-Bergamot Essential Oil is pressed from the peel of the Bergamot Orange, a hybrid citrus fruit grown mainly in Southern Italy, Southern France, and also in Cote d'Ivoire West Africa. Thought to be a cultivar of citrus limetta and citrus aurantium, the fruit of the plant is not known to be edible, and the juice is particularly sour and bitter. Bergamot is highly prized for its use in aromatherapy as a digestive aid, antipressant and anti-malarial aid. It is used in a large percentage of men's and lady's perfumes, as well, due to its distinctive low, warm citrus note. Bergamot is perhaps best known as the scent behind Earl Grey tea. The oil has a rich amber color.

Bubbles- Air-filled spheres made of thin films of solutions. Water alone will not make stable bubbles. However, the addition of soap decreases the surface tension of water, and boosts its ability to form stable bubbles. Coconut oil is commonly added to natural soap formulas because of its ability to create stable bubbles.

Butters- Fats that are solid at room temperature. Butters are naturally occurring fats found in many types of plant material, but especially in the seeds. Butter was traditionally extracted using a mortar and pestle, but is now mainly collected using mechanized processes, such as the Universal Nut Sheller. Butters are known for having non-saponifiables. These are fatty acids/oils that are not converted to soap, but rather, remain in the soap and provide conditioning and moisturizing qualities.

Calendula- Calendula is a flowering plant known by the common name, "pot marigold." (Common garden marigolds are not calendula, but rather "Tagetes," or French Marigold). Calendula is an excellent colorant for natural soap, and is known to impart a golden color.

Caustic- Caustic is a term used to describe corrosive substances which are also strong bases. Known to be irritants to the respiratory and gastrointestinal tracts, Caustics can defat skin, and cause severe chemical burns. Well known caustics include ammonia and sodium hydroxide (lye). Through the process of saponification and the subsequent curing of the soap, lye is converted into harmless, non-caustic soap. All soap made with lye is commonly called lye soap.

Certified Natural Fragrance Oil- We know of many natural things that do not produce usable essential oils (apples, cucumbers and raspberries are great examples). What is responsible for their scents? Chemical compounds combine to form every natural plant's unique scent. Lavender's characteristic scent is made primarily of Linalyl and Linalool. Other flowers contain these same compounds, yet, due to the presence of other scent compounds, they have scents uniquely different from lavender. Scent chemists are able to isolate these scent compounds and blend them with other isolates, to create scents that are reminiscent of many natural scents. These scents are then certified by the chemists who create them, to contain nothing but natural isolates, and perhaps, essential oils. They are different from synthetic fragrance oils that are made with little to no natural isolates, and instead contain synthetic, artificial scent compounds.   

Chamomile- Chamomile is a flowering plant commonly used as a scrubby addition to natural soap. Chamomile also produces a useful essential oil that can be used to scent handmade soap. Makes a lovely tea.

Clay- Clays are naturally occurring mineral compounds which are known for their ability to absorb water. Some clays are better absorbers than others. When added to natural soap and cosmetic items, clays impart color, exfoliating texture, and/or provide oil and impurity-absorbing benefits. Cosmetic clays can also be added to "shaving soaps," due to their ability to increase "slip," reducing drag of a razor.

Cold Process- Cold Process is the method of soap making that involves mixing melted oils with a lye/water solution, and stirring until a thickened condition called "trace" is achieved. The soap batter is poured into molds and typically insulated for a day or so before being unmolded or cut into bars, and allowed to cure for several weeks or more.

Colorants- Minerals, dyes, lakes, herbs and other ingredients added to cosmetic products to impart color are collectively called "Colorants." Naturally occurring oxides and dried herbs, or herb-infused oils are commonly used in natural soap. Artificial dyes are also available but seldom used in products claiming to be "natural."

Dead Sea Salt- Dead Sea Salt contains 40% more mineral content than other sea salts. Naturalists believe these minerals are beneficial to the skin. Up to 98% of the salts in regular sea salt are Sodium Chloride. Dead Sea salt, by contrast, contains only 14-18% sodium chloride. The remaining salts consist of magnesium, bromide, chloride and others. Products containing Dead Sea Salts have been shown to be effective in treating the itchy symptoms of psoriasis and eczema. This has been attributed to the abundance of Magnesium Chloride in Dead Sea mud, from which the salt is obtained.

Detergent- Detergents are substances intended for use as cleansing agents. The term is sometimes used to differentiate non-soap cleansers (those made without the chemical process of saponification) from soap-based (made with saponification) cleansers. Typically, detergents are made from a blend of surfactants.

Essential Oil- Essential oils are the aromatic compounds of a plant, often obtained by steam distillation or expeller pressing. The fragrance of an essential oil contains the volatile, naturally occurring fragrance of the plant, and some can be used to scent handmade soap or other cosmetic products. Some scents do not survive the heat of the saponification (soap making) process. Some plants do not produce valuable essential oils, or produce such little product, that extraction and production of their essential oil is not a worthwhile endeavor.

Fatty Acids- Carboxylic acids with long hydrocarbon chains, ranging from 8-30 carbons. Found naturally in plant oils and animal fats. These are converted into the salts of fatty acids when reacted with lye, creating "soap" through the process of saponification. During the saponification process, the carboxylic chain is broken, resulting in a glycerol group and a salt of the fatty acid. The resulting soap will have different qualities depending on the length of the original carbon chains of the fatty acids in the oil used. Longer carbon chains lead to higher cleansing properties.

Fragrance Oil- Fragrance oils are aromatic compounds used to impart scent. Some are completely synthetic, while others are made with blended or pure natural plant extracts, such as esters, and can be used to provide fragrance in cosmetic products. Often suspended in propylene glycol, mineral oil, or natural vegetable oils.

French Green Clay- Green clay contains illite, a mineral common in clay. Clay minerals are created by the weathering of rocks and soils. Green clay gets its color from decomposed plant material, including sea kelp and algae. Many deposits of green clay are found in Southern France. However, recent deposits have been found in Wyoming, USA. Adding green clay to natural soap can increase the exfoliant properties of the handmade soap, and add oil absorbing properties as well.

Green Clay- Green clay gets it's color from decomposed plant matter, such as sea kelp and algae. This plant matter also lends numerous beneficial minerals including calcium, cobalt, copper, potassium, manganese, magnesium, phosphorus, selenium, and zinc. Green clay is often added to soap for it's oil absorbing properties.

Hot Process- the method of soap making that involves combining oils and lye/water over a heat source, and stirring until a very thick solution develops. The resulting batter is packed into molds and allowed to harden. Hot process soaps are quick to cure, being ready for use immediately, but lack the refined texture of cold processed soaps.

Humectant- A hygroscopic substance, which means that it attracts water. Humectants are used in cosmetic products such as natural soap to impart moisturizing qualities to the soap. Humectants actually pull water from the air, rather than drawing it from the skin. This contributes to a "moist" feeling. Honey is a common humectant additive for natural soap products.

INS scale- A scale mentioned by Dr. Robert McDaniel is his book, "Essentially Soap." INS basically assigns a number to every soap formula, as an indication of the idealness of the soap. A number within 10 points of 160 is ideal. The INS scale factors in such things as specific oils used and iodine contents of those oils to arrive at an INS number.

Kaolin- Kaolin is sometimes called China Clay, and contains up to 95% kaolite, an abundant clay mineral. Kaolin also can contain quartz, mica and feldspar. Kaolin is often used in cosmetics and soaps as a natural colorant. Kaolin has slight oil absorbing ability.

Lather- The highly desirous, bubbling ability of a soap, when rubbed in the presence of water. Often an elusive quality in handmade soap, lather can be increased by adding long chain carboxylic acids such as coconut oil.

Melt and Pour-A type of soap product that is purchase in a block or chunk form, melted down, and remolded to create individual handmade soaps. Melt and Pour base can either be soap based (made with lye), or detergent based (synthetic), or a combination. It is a safe way to create individual bar soaps without having to deal with lye directly. However, it is inaccurate to state that Melt and Pour Soap is made without lye.

Oil- Oils are fats that are liquid at room temperature.

Olive Oil- the oil of the fruit of the olive tree, Olea europaea, obtained by expeller pressing or centrifuge. Contains oleic acid, a fatty acid that contributes conditioning power to bars of natural, handmade soap. Used since antiquity as a skin treatment. Known to quickly pentrate skin and moisturize, aid in cell regeneration, and improve skin's softness. 

pH-A chemical measurement of the Potential Hydrogen of a solution. A number assigned to a solution that describes the balance of alkalinity and acidity. Lye has a high pH, which, when used to create soap, is imparted to the product. pH tends to decrease as soap cures. Most cured natural soaps have a pH between 8 and 11. Water is said to be "neutral." It has a pH of 7.0.

Potassium Hydroxide- A strong alkaline, or "lye," used to produce liquid soaps through the process of saponification.

Rose Clay- A kaolin clay that imparts a red/rose color to soap and cosmetic products. Has a minimal drying effect.

Sea Salt- Sea salt is added to cosmetic products to boost the moisturizing properties and contribute minerals.

Soap- Soap is a cleansing substance, made from plant and/or animal oils, natural butters, and possibly colorants or other additives, that have been reacted with a strong alkaline solution (lye) in a process known as saponification.

Soda Ash- A thin, white film that forms during the insulation period on a new batch of handmade soap. Soda ash is sodium carbonate, and is the result of lye reacting with air. It is water soluble, and can be wiped away with a damp paper towel, or rinsed off. Soda ash is also referred to as simply "ash" or soap ash. It does not effect the quality of the finished soap. To limit ash formation, try covering your soap with a layer of plastic film such as Saran Wrap, or wax paper, prior to covering with blankets/towels during insulation. Do not remove the covering until the soap is cool to the touch, and no longer "zaps" when you perform a zap test.

Sodium Hydroxide- A strong, caustic alkaline used in the making of solid soap.

Sodium Laureth Sulfate- Sodium Laureth Sulfate (Sodium Lauryl Ether Sulfate, SLES) is a synthetically made surfactant with detergent properties, used in some commercially made cosmetics as a detergent, emulsifyer and moisturizer. Although some products made with SLES have shown contamination with 1,4-dioxane, a probable carcinogen, the trace amount of the contaminant is well below levels that would be of concern. Prolonged use, or increased concentration of SLES, can lead to skin and eye irritation. Ingestion would likely cause little more than diarhhea. When used at 15% or lower concentration, it is considered by the FDA to be safe.

Sodium Lauryl Sulfate- Sodium Lauryl Sulfate (Sodium dodecyl sulfate, SDS, SLS), is asynthetically created surfactant used in cosmetic products and cleansers to boost lather and cleansing ability.  With prolonged exposure, and increased concentration, SLS has been shown to be an irritant, however, it is has not been shown to be a carcinogen. Sodium Lauryl Sulfate is more commonly used than its relative, SLES, due to it being less expensive to produce. When used at 15% or less concentration, it is considered by the FDA to be safe.

Trace- A thickening, cloudy condition of the mixture of water, lye and oils that indicates saponification is occurring in the making of natural soap.

Triglycerides- the essential components of oils and fats, made of three fatty acids, joined to a glycerol group at the fatty acids' carboxylic-group ends. Petroleum based hydrocarbon "oils" do not contain fatty acids, cannot form triglycerides, and are therefore, incapable of making natural soap.

Ultramarine Blue Oxide- A strong blue-colored oxide made of limestone and lazurite, the blue mineral found in the semi-precious stone, Lapis Lazuli. True, natural ultramarine blue is the most difficult pigment to grind due to its hardness. Ultramarine Blue that is used in cosmetics is lab synthesized to be chemically equivalent to, yet without the harmful impurities that exist in, natural earth minerals.

Zap Test- An easy test to determine lye-heaviness of a finished bar of natural soap. To perform a zap test, the tip of the tongue is touched briefly to the bar of soap. Any reaction, such as burning, stinging, or a quick "zap!" indicates that the amount of unreacted lye in the bar is perhaps high, and that the bar will be too strong for use as a body soap. Some have equated the "zap!" feel to that of touching the tip of the tongue to a battery- however, the author has never licked a battery and cannot attest to that. If the soap produces a zap on the tongue, a simple swish with water, or lemon juice will neutralize lye in the mouth, if any. Soap that doesn't pass the zap test can sometimes be re-batched (grated, heated, melted and re-molded) and "saved," or can be grated finely and used in the laundry.