If you have ever wondered what a humectant is, you will find the answer here! We have compiled a complete list of soap terminology and definitions, including the most commonly used acronyms. It is a wonderful source of reference to use while you are creating homemade works of art.
Cold Process / Cold Kettle: The process of making soap without using any external
Hand Milled / Basic Rebatch: The process of melting down fully-saponified (pre-made
cold processed) soaps (while possibly combining it with new additives) to make a
new soap creation.
Hot Process: The process of making soap by utilizing an external heat source (such as a
crock pot, double boiler, etc.) to accelerate the saponification process.
Melt-and-Pour / Soap Casting: The process of handcrafting soap by melting a ready
made soap base, adding fragrances/colors/etcetera, and shaping the soap using
Antioxidant: An ingredient that prevents oxidation (the process where oxygen reacts
with oils and turns them rancid).
Aromatherapy: The use of essential oils or plant extracts to alter a person’s mental or
physical well being.
Astringent: A substance that constricts or tightens the skin. It is used to remove oils
from the skin.
Beeswax: Wax obtained from processing the honeycomb. Often used in soaps, lip
balms, and other cosmetics.
Botanical: A material that is obtained from a plant or plants.
Butter: A vegetable oil or fat that has a solid or nearly solid consistency at ordinary
Carrier Oil: A vegetable or nut base oil that is usually liquid in form.
Colorant: A solid or liquid substance that is used to color soaps and cosmetic products.
Comedogenic: To aggravate or produce acne.
Cosmetic: A product that is applied to the human body in order to beautify, cleanse, or
alter the appearance without affecting the body’s structure or functions.
Cosmetic Grade: A product that is approved by the U.S. government for safe use
directly on the skin.
Cure: The process in which soap fully saponifies undisturbed, usually taking several
Deodorize: The process in which odoriferous matter is removed from an oil or fat.
Double Boiler: Pan or other metal container placed inside a pot of boiling water. This
method can be used to melt various items.
Embed: An object, such as an artificial flower, plastic toy, ribbon, etcetera, that is set
securely in the soap for decoration.
Emollient: An additive that is a moisturizer. It helps retain water in dry skin while it
softens and soothes.
Emulsifier: An additive which makes it possible to blend oil and water.
Emulsion: The stable blend of oil and water (i.e. lotion).
Essential Oil: A pure oil that is derived from plants, possessing the odor and other
characteristic properties of the plant. They are known for their aromatic scents
and remedial applications.
Exfoliant: An abrasive added to cosmetics that aids in removing dead skin cells to
reveal softer, fresher looking skin.
Fixed Oil: The non-volatile oils obtained from botanical bases such as vegetable oils.
Flash Point: The lowest temperature at which a substance will ignite. Some substances
will combust on their own if they reach the flash point. Fragrance oils would
have to be at their flash point and come in contact with a spark or open flame in
order to combust.
Fragrance Oil: A synthetic oil that is chemically created. They are known for their
wide variety of aromatic scents and range of uses.
Gel Phase: The state that soap is in when it has started the saponification process – it
turns semi-translucent and beings to produce heat.
Glycerin: A byproduct created during saponification. Often used in soaps, lubricants,
Glycerin Soap Bases: A wide variety of ready made soap bases that are used in Meltand-
Pour soap making.
Herb: An aromatic plant that is used for its medicinal properties, flavor, and scent.
Humectant: A substance that draws moisture to itself and promotes the retention of
moisture. Used in bath products to keep the skin from drying out.
Hypoallergenic: Unlikely to cause an allergic reaction.
INCI Name: International Nomenclature of Cosmetic Ingredients. This name is
required when labeling cosmetics for sale.
Infusion: Made by steeping botanicals in water or oil.
Insoluble: Not dissolvable in a liquid, such as alcohol or water.
Insulate: Wrapping a blanket or towel around the soap mold to help the soap retain
Lard: The partially solid or solid fat obtained from a hog.
Layering: The process of pouring multiple levels of soap, usually of varying colors.
Loofa / Loofah / Luffa—The dried fibrous section of the loofa fruit that is used as an
Melt Point: The temperature at which solids will turn to liquid.
Mise En Place: Measuring out all of the ingredients ahead of time and putting away
everything except what will be used in the recipe – helps with getting organized
and staying focused while working.
Mold: A hollow form that is used for shaping soap. Molds are normally made out of
heavy duty plastic, rubber, etcetera.
Natural Soap: A soap made from all natural ingredients; free from chemical,
petroleum, or other artificial ingredients.
Opaque: Impenetrable to light; not allowing light to pass through.
Paraffin: A petroleum based wax that is used in cosmetics.
Potassium Hydroxide (Potash): Also known as caustic potash. The base that is formed
from combining hardwood ash and water. It is used in producing soft and liquid
Preservative: An ingredient that prevents cosmetics and soaps from decomposition due
to chemical change or bacterial action.
Pumice: A light and porous lava that is used in powdered and solid form as an abrasive.
Refined: The process of removing impurities from a natural or crude base.
Rendering: The process of heating tallow or lard to a liquid state to remove solids or
Sea Salt: Evaporated salts from sea water, not mined or mechanically processed.
SAP Value / Saponification Value: The amount of potassium hydroxide in milligrams
required to saponify 1 gram of a specific oil. Each fat or oil has a SAP Value. The Saponification Value uses potassium hydroxide as the base, therefore, simple
arithmetic must be done to convert the measurements into sodium hydroxide.
Saponify / Saponification: The process or reaction of combining a base (fat) with an
alkali (sodium hydroxide) to produce a salt (soap) and a free alcohol (glycerin).
Seize: The unexpected thickening and uneven hardening of the soap mixture during
processing. Caused by temperatures, oils, or when adding synthetic fragrance oils
or essential oils to the mixture.
Soap: The salt resulting from the combination of oils and fats with an alkali. It is a
simple cleansing agent consisting of a chain of carbon, hydrogen, and oxygen
atoms. It cleans because the one side of the molecule attaches to water and the
other side attaches to dirt and oil.
Sodium Hydroxide (Lye): Also known as caustic soda. A strong alkali used to make
Soluble: Dissolvable in a liquid, as in water or alcohol.
Superfatted / Superfatty: The addition of extra butters or oils that remain unsaponified
within the finished soap. These excess butters and oils contribute to the
moisturizing properties of the soap.
Synthetic: Artificially produced – not of natural origin.
Tallow: The fat obtained from animals such as sheep or cows.
Tocopherol: Any of the four forms of Vitamin E (alpha-, beta-, delta-, or gamma-), an
antioxidant that is added to soaps and bath products as an emollient due to its
moisturizing properties. (Alpha-tocopherol has the greatest amount of Vitamin
Trace: The state in which soap holds its shape. It is most noticeable when the soap is
drizzled upon itself and leaves a trail before disappearing back into the mixture.
Translucent: Allowing light to pass through (sometimes in such a way that the objects
on the opposite side are not clearly visible).
Unrefined—The natural unaltered base.
Unsaponifiables: Ingredients that do not react with sodium hydroxide during
saponification and remain in their original state. These components contribute to
the moisturizing or other skin nourishing properties of the soap.
Viscosity: The resistance of a liquid or a semi-liquid to be fluid or flow.
Volatile Oils: Oils that evaporate or vaporize easily at room temperature.
Water Soluble: Dissolvable in water.
CP: Cold process
CS: Closed System
D&C: Prefix used to designate the approved use in drugs and cosmetics.
DB: Double Boiler
DH: Direct Heat
EO: Essential Oil
FCC: Food Chemicals Codex-The industry standard for listing food grade ingredients.
FD&C: Prefix used to designate the approved use in foods, drugs, and cosmetics.
FO: Fragrance Oil
HP: Hot process
MP / M&P: Melt and Pour
RBD: Refined, Bleached, Deodorized
This Dictionary of Soap Making Terms is provided by Nu-Scents for the personal use of our customers. No portions of this document may be reproduced for distribution, sale, or publication of any kind without the expressed written consent of Nu-Scents Wholesale, LLC.