Soap Glossary has the most comprehensive glossary of soap-terms on the internet


 Gritty or rough substances, which are added to soap to help scrub away dirt or dead outer skin cells. Also helps remove excess oils from skin. Also considered an exfoliant. Avoid with delicate or dry skin types.

Absolute: Products, not strictly essential oils, obtained through chemical solvent extraction.

Additives:  Ingredients that can be added to processed soap, which are not included in the original recipe which was used to calculate the SAP value for lye purposes. This additive category would include all ingredients with the exceptions of: lye, water, soaping oils, butters, and fats. This means that additives would describe the addition of fragrance oil, soap colorant, optiphen, vitamin E, herbs, clays, etc. Note: If you have a superfat recipe, any leftover or excess oils, butters, or fats, not saponified by the lye solution would also be considered an additive.

Alkali:  Any compound with a pH higher than 7. Alkali is also referred to as a base. Both sodium hydroxide and potassium hydroxide are alkalis (or bases).

Allergen: Hypersensitivity or reaction caused by a substance or ingredient.

Anhydrous:  A substance that does not contain water.

Antibacterial:  A substance that has the ability to fight bacteria effectively.

Antioxidants: Any substance that slows or prevents oxidation in other substances.

Antiseptics: Ingredients that inhibit the growth of bacteria.

Astringents: Substances or additives that tighten or close skin pores. 

Aromatherapy: The use of selected fragrant substances to affect mental or physical well being of person.

Aromatic:  Having a strong pleasant odor

Aromatherapy Benefit: The emotional or physical effect evoked by aromatic essential including balance, energy, rejuvenation, cleansing, deodorizing and purifying.

Aroma/aromatic: Having scent, flavor or taste

Attar: A perfume or essential oil obtained from flowers or petals.


Base:  Any substance with a pH level higher than 7.

Blenders: Additional scents that are combined with a main scent.

Botanical Name: Refers to the Latin name of the plant in the biological classification system.


Castile Soap:  An olive oil soap bar named after a region in Spain where it originated. Now a term for soap containing only olive oil.

Caustic:  Usually a term to describe a very strong acid or base. An example of a caustic ingredient is sodium hydroxide (lye).

Caustic Potash: See Potash

Cold Process:  The term cold process is a method of soap making without outside heating source required for saponification.

Cold Process Oven Process:  This soaping process, usually referred to as CPOP, equals the cold proces, but after trace, the molds are placed into a 170-degree oven for 1- 2 1/2 hr.

Cosmetic Grade: This refers to ingredients that are safe for use on the body or in cosmetics.

Cure: The time it takes to saponify soap, so that there is no longer any active lye present.


D&C:  D & C is the abbreviation for drug and cosmetics. If something is approved as D&C safe, then it can be used for cosmetics or in drugs.

Dermal: Pertaining to the skin.

Deodorize:  To remove the scent from a product. This is beneficial when making scented soaps so that the fragrance remains true.

Detergent:  This agent has cleansing benefits and performs very similar to soap. However, detergent is made from chemical compounds other than fats/oil/butters and lye.

Discount: The word discount in this context means ‘to reduce or use less’. Usually refers to either water or lye in soap making.

Disinfectant: Prevents or combats the spread of germs.

Dreaded Orange Spots or DOS:  These spots occur in processed soaps that contain a large amount of soaping oils that have turned rancid.


Enfleurage: Age-old method of extracting essential oils using odorless fats and oils to absorb the oil from the plant material.

Embeds:  Embeds refer to pieces of soap that are placed into the processing soap during a light trace stage.

Emollient:  Refers to having certain properties that are both soothing and softening to the skin.

Emulsifying Wax:  This is an emulsifier used in hair and skincare.

Emulsion:  A blend of substances that are normally not mixable. Becomes an emulsion when emulsifying wax is combined with oil and water.

Essential Oil: Highly concentrated, volatile, aromatic essences of plants.

Exfoliate:  An additive that is added to processed soap that allows for the removal of dirt and debris from the skin. Also removes dead skin cells.

Exothermic:  A term referring to the heat that is produced and released when a chemical reaction occurs.

Expeller Pressed: A mechanical method for extracting oil from plant material. The material is squeezed under high pressure to remove the oils.

Expression: Method of obtaining essential oil from plant material. Also known as cold press extraction.

Extraction Method: A method by which essential oils are separated from the plant material. It can be eg. distillation, expression, and solvent extraction.


F,D&C:  F,D&C is the short abbreviation for Food, Drug, and Cosmetics. If something is F,D&C approved, that means that it is a safe ingredient for use in food, drug, and cosmetics.

Fatty Acids–  Fatty acids are compounds either saturated or unsaturated, that are found in all fats and butters. The fatty acids are what is responsible for giving your soap bars conditioning, creamy lather, bubbles, hardness, and cleansing ability

Fillers: Ingredients that add bulk, or extend the soap.

Fixatives: Ingredients that stabilize volatile oils and prevent them from evaporating quickly.

Fixed Oils:  These oils can be heated without evaporating. Coconut- or palm oil eg.

Flash Point:  The possible lowest temperature that will inflame the vapors of a liquid when introduced to a source of ignition. both fixed and liquid oils have a flashpoint.

Flashing Off: Vaporation of fragrance oil that has been added to hot soap.

Food Grade: Safe for use in food by the Food and Drug Administration.

Fragrance Oil:  A blended combination of essential oils, synthetic aroma chemicals, and resins.


Gel or Gel Fase:  A possible phase of saponification. It sometimes occurs at the beginning of the process, and refers to a short period of time where the soap batter becomes a warm clear gel.

Glycerin:  A natural emollient and humectant, glycerin is a product of processed soap. It is also often removed from commercial brands soaps and used to created creams and lotions.


Hand Milling: A way to produce soap from existing soap. This allows you to make soap and adding the colors and scents that you prefer afterwards. Existing soap is grated, melted, and reformed after additives (fragrance or color, etc.) have been added.

Herbal: Pertaining to natural botanicals and living plants.

Hot Process or HP: This soaping process has steps very similar to the CP soap steps, but varies in that you are adding heat to the equation to speed up the saponification process.

Humectant:  An ingredient that not only attracts water from the environment, but also aids the skin in absorbing water.

Hydrating: Restoring or maintaining normal proportion of fluid in the body or skin.

Hydrogenated Oil:  An oil that has the addition of hydrogen added to it to make it a solid or semi-solid at room temperature.

Holistic: A natural approach to healing other than Western medicine.

Homeopathy: Therapy using plant, animal and mineral substances in dilutions to overcome illness by stimulating the body’s natural immune system.



INCI Name:  Mandatory for labeling in the US and Canada, the INCI names were created to ensure that all ingredients would be listed the same on various cosmetic products. This also allows for ease on consumers when comparing ingredient lists on cosmetics. INCI stands for International Nomenclature Cosmetic Ingredient.

Infusion:  Taking an additive such as a herb, and allowing it to steep in a liquid to extract the herb’s beneficial aspects.

Insoluble: Unable to be dissolved in a liquid.

Irritant: Substance or material that produces irritation or inflammation of the skin.


Lye:  Essential to the saponification process, lye is a caustic base. Lye can also be referred to as either sodium hydroxide (used to make bar soaps) or potassium hydroxide (used to make liquid soaps).

Lye Discount:  The method of purposely decreasing the amount of lye that should be included in a soaping recipe.


Main Scent: Dominant scent to which other scents is added, to create a blended scent.

Melt and Pour: A pre-fabricated soap base that only needs a few steps before use.

Melting Point:  The temperature at which a soaping oil will turn from a solid to a liquid.

MSDS:  The abbreviation of Material Safety Data Sheet.


Natural:  Anything that is of the earth, not containing any man made or synthetic additions.

Nervine: Strengthening or toning the nerves or nervous system.


Organic:  Without the additions of anything man made or chemically altered. Eco-friendly materials are also often referred to as organic,

Olfactory: Relating to or connected with the sense of smell.


pH scale:  A form of measurement for the acidity or alkalinity of a substance in ratio to water. Very important knowledge for any soaper.

pH strip:  Litmus paper that, when dipped into a liquid or set on a bar of soap, will show a color. The color is then compared to a chart to find the pH level.

Photosensitizer:  A substance that once used on the skin will make the skin super-sensitive to the sun or to sunlight.

Preservative:  An ingredient that is added to a substance that will prevent the breakdown and spoilage from microbial growth.

Potash or Potassium Hydroxide:  Symbolized as KOH, this is used for lye solution of gel or liquid soaps. Also known as caustic potash.

Potpourri: Fragrant mixture of dried herbs and flowers. Usually scented with synthetic fragrance oils.

Preservative A preservative is a natural or synthetic chemical that is added to products to prevent decomposition by microbial growth.


Rancid: Soap, like other organic material, spoil or go bad. Sniff for metallic, bitter, or soapy aromas.

Rancidity:  The breakdown or spoilage of oils/butters/fats used in soaping.

Rebatching:  Considered a do-over in soap making. The process involves the use of soap that was already crafted through CP or HP. The processed bars are grated down and melted. A liquid, like water or milk, is added to help prevent scorching of the soap shavings.

Refined oils:  These are oils that have been filtered to prevent impurities.

Refrigerant: Ingredient that cools inflammation or eases muscle pain.

Relaxant: Ingredient that is soothing, relieving strain or tension.

Rendering: A process in which impurities in animal fats is removed.



Safety Equipment A category for all of the equipment used to keep one safe during the soaping process.

Saponification:  This is the name of the chemical reaction that the lye solution and oils/fats/butters go through when making soap.

Saponification Calculator: Online application or a spreadsheet that calculates the amount of lye required to react with the oils in a soap recipe.

SAP Value:  The abbreviation for Saponification Value. This refers to the number of milligrams of lye that is needed to completely saponify one gram of a specific oil/fat/butter in a soap recipe.

Seize:  A term referencing the condition of the soap batter when saponification has occurred, and has started to solidify. This occurs while mixing together the ingredients and the batter becomes too thick to easily or pour into a mold.

Sedative: Ingredient that reduces functional activity or calms.

Single Note: Pure, 100% natural essential oil with no additives or adulterations.

Soap Measurements:  Soap Measurements are measured in weight, not volume.

Soda Ash: Sometimes forming on processed soaps, this powdery substance has no direct negative effect on soap bars. Soda ash can be cut or wiped off bars. Insulating soaps while in the mold will help prevent soda ash. Soap that has soda ash can be sprayed with rubbing alcohol to improve the appearance of your soap.

Sodium Hydroxide:  Symbolized as NaOH, this is used for lye solution in solid bars of soap. Also known as caustic soda. This ingredient is a very strong base with a pH of 14.

Soluble: Able to be dissolved in a liquid such as water.

Stimulant: Ingredient or substance that temporarily speeds the functional activity of a human tissue.

Superfat: This term involves purposely adding an excess of soaping oils or fats to your batter. This is done to intentionally make your soap bars richer in soaping categories such as creaminess, moisturizing, bubbles, etc.

Surfactant: A substance that reduces the surface tension of a liquid when it is dissolved. In soap, surfactants allow for the dirt and impurities to be rinsed off of the skin.

Synergistic: Characteristic in which the total effect is more effective than the individual parts.

Synergistic Blend: Combination of multiple essential oils that produce a completely new aroma with a different therapeutic effect.

Synthetic: Artificially produced substance designed to imitate that which occurs naturally.


Tare: A function on scales that allows you to temporarily reset the weight to zero. This is useful if you are adding multiple ingredients to one bowl.

Tallow: Rendered from animals. This hard fatty substance can be used for soap making.

Trace: This term references the stage in the soaping process where the batter begins to thicken because of the saponification process. You will know if your soap batter is at trace by drawing up some of the batter with your blender to see if it leaves any trails on top.


Variegated: A way of saying that the soap has many different colors, rather than a single shade.

Vegan:  Products that are produced without the use of any animal ingredients or animal parts. If a product contains tallow/lard/beeswax, it cannot be vegan. Se all recipes for vegan soaps here.

Viscosity: Pertaining to the thickness or thinness of a liquid.

Volatile:  Oils that will evaporate quickly under normal temperatures.

Volatilization: Rate of evaporation or oxidation of an essential oil.

Volcano Effect:  This term describes what can happen if water is added to lye and not the other way arround. It is a dangourous cemical reaction and must be avoided.

Wild: Growing spontaneously, not cultivated.

Water Discount–  The method of purposely decreasing the amount of water that should be included in a soaping recipe. Doing so will accelerate the saponification process, and is not recommended for new soapers.

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