Soapmaking Terms

This is a list of various terms and acronyms that are commonly used in soap- and toiletries-making information and recipes. If you have anything you're not sure about, that you'd like to see defined, drop me an email.


Noun — An ingredient that prevents oxidation. Oxidation is the process whereby oxygen in the air reacts with oils and turns the oils rancid -- think of it like air "rusting" your oils like water rusts metal. Antioxidants block this reaction and thereby prolong the life of your oils. Note, however, that an antioxidant is not the same as a preservative. They do not prevent bacterial or mold growth. Many oils have natural antioxidant properties by being high in vitamin E, such as wheat germ oil.
Cosmetic Grade
Adjective — Cosmetic Grade is a term which refers to whether or not a product is approved by the (U.S.) government for use directly on the skin. For example, many pigments are what is called industrial grade, which means that they are for use in things such as polymers or plastics or paint, not for products for use on the skin. Cosmetic grade fragrance oils are fragrance oils which have been diluted with a solvent or carrier oil so that they are safe to use straight on the skin (but are, therefore, weak for use in products like soap).
Abbreviation/Acronym — Double Boiler. Usually used in "DBHP," double-boiler style hot process soap.
Abbreviation/Acronym — Direct Heat. Usually used in "DHHP," direct-heat style hot process soap.
caustic soda
Noun — Another name for sodium hydroxide.
Abbreviation/acronym — Closed System. Usually used in "CSDBHP," closed-system double-boiler hot process soap.
Abbreviation/acronym — Cold Process soap (aka "cold kettle" soap), which is soap that is made without cooking it.
Noun — An ingredient that imparts a softening, soothing sensation to the skin. A moisturizer, emollients help retain water in dry skin.
Noun — An ingredient which faciliates the blending of oil and water. You use an emulsifyer to create lotions or creams. You can use various conbinations of borax and beeswax or emusifying-wax (e-wax for short) as an emulsifyer.
Noun — An emulsion is a stable blend of oil and water, such as lotion.
EO or Essential Oil.
Abbreviation/acronym, Noun — Essential oils are the oils extracted from actual plant material, such as tree bark, leaves, flowers, roots, etc. Essential oils are good for imparting special properties to your soaps -- for example, lavender essential oil is known to be an antiseptic -- while also giving the scent of the plant from which the oils came. Essential oils usually require very large amounts of plant material to produce even small amounts of oil. Due to this, essential oils can be very expensive. In addition, some essential oils are dangerous to humans and animals. Please do not use essential oils "because it smells nice" without first reading up on them! Some very nice scents can cause irritation, rashes, physical problems (like a racing heart rate), or even be toxic in very small amounts, such as wintergreen. The ones you like *might* be harmless, but then again they might not, so please read up on your choices. Keep essential oils locked up, out of the reach of children or pets.
FO or Fragrance Oil
Abbreviation/Acronym, Noun — A fragrance oil is a scenting oil made from natural and synthetic sources. Fragrance oils are good for scenting soaps inexpensively -- they can duplicate scents that are prohibitively expensive in nature, for example rose or sandalwood. Since they are composed partly of chemicals or other synthetic materials, they can cause allergic reactions in some sensitive folks. If you are making soaps because you have sensitive skin, you might want to order samples of the FOs and test them out before you invest in enough for a whole batch. FOs can also cause your soaps to seize up -- that is, when your soap has traced and you are adding your FO scent, it can make the soap change from a nice pourable pudding consistency to a hard, unpourable, unmoldable blob. Some people think that warming the FO prior to adding it helps alleviate seizing. Many scent sellers will test their products in soaps first, so check their catalog/web site to make sure the FOs will work in your type of soap.
Gel phase
Noun— Gel means the state the soap is in when it's started the saponification process -- it turns semi-translucent, sort of like Vaseline, and starts to produce heat. The heat is a byproduct of saponification, and it also helps speed it along, so generally, gel stage is good (unless you're making a milk soap or something where you're worried about the color). Usually it gels from the inside out, and unless you have a lot of soap, it won't gel all the way to the edges (because the edges are cooler than the inside, so they won't heat up enough to gel even while they're saponifying). You can help your soap gel by insulating it, which for most people takes the form of wrapping a blanket or towel around the mold to help retain heat.
Abbreviation/Acronym — Goat's Milk Soap. Soaps made with milk are supposed to be smoother and nourishing; goat milk is often preferred over cow milk.
GSE or Grapefruit seed extract
Abbreviation/acronym, Noun — GSE is the extract from the seeds of grapefruit, and is reported an antioxidant, though there is a lively debate on its efficacy. See also antioxidant. Use between .5% and 1% in soaps, or between .5% and 5% in lotions or creams. More information is available from
Abbreviation/acronym — Hot Process soap. This is another name for cooked soap, which is when you pour your soap ingredients into a pot and literally cook it on the stove, until all the water is evaporated and the saponification process is complete.
Industrial Grade
Adjective — Industrial Grade is a term which refers to the intended use of a product. Things such as industrial grade pigments or micas are not intended for use in skin-care products such as soap or lotion. Use Cosmetic Grade ingredients instead.
Noun — A humectant is a substance that draws moisture to itself or promotes the retention of moisture -- that is, something that helps keep your skin from drying out. See glycerine for an example.
Abbreviation/acronym — Chemical symbol for Potassium Hydroxide, the kind of lye that you use for soft/liquid soaps. Commonly known as potash.
Noun — "Lye" is a term that's used to mean a lot of things, but they're all caustic. Usually it refers to the chemical sodium hydroxide, but it can also mean a solution of sodium hydroxide dissolved in water. Sometimes it's used to refer to potassium hydroxide, which is also known as potash.
Manufacturer's Grade
Adjective — Manufacturer's Grade is a term which refers to a product which is to be used in the manufacture of another product. For example, there are manufacturer's grade fragrance oils, which are not be used by applying them directly to the skin, but instead must be used in other products such as soap, bath fizzies, or candles.
M&P or MP
Abbreviation/acronym, Noun — "Melt and Pour" refers to soap base (frequently called 'glycerin soap') that's already made and all you have to do is melt it down, add fragrance and colorants, and pour it into a mold.
MSDS or Material Safety Data Sheet
Abbreviation/acronym, Noun — Material Safety Data Sheets are documents which state information such as INCI name, intended use, known problems, and safety information on ingredients. These documents may be required by OSHA if you have employees working in a soap business. They are good practice to have on hand in any event, especially in an emergency. (You can take the MSDS to the emergency room with you and the doctors can help you much more quickly.) They should be given to you free upon request by your vendor.
Abbreviation/acronym — Chemical symbol for Sodium Hydroxide, aka caustic soda. Sodium hydroxide is used to produce hard bar soaps.
potash or caustic potash
Noun — Common name for potassium hydroxide, the base that you can get from combining hardwood ash and water. This is used in producing soft and liquid soaps.
Noun — Melt down your fully-saponified or separated soaps and give it another try! There are several methods for rebatching, such as double-boiler, oven, crock pot, oven baggie, etc. In a nutshell, it means shredding or finely chopping finished soap, adding a small amount of liquid (often milk), maybe some oil, maybe some scent, and molding it when fully melted and mixed. Rebatched soap has the advantage that you are working with fully saponified soap -- no raw lye -- and some fragrances, herbs, or colorants that may mutate in the presence of lye will remain truer to normal. The disadvantages are that, depending on your method, it can be a pain to do and to clean up after!
ROE or Rosemary Oleoresin Extract
Abbreviation/acronym, Noun — A clear viscous liquid extracted from rosemary oil which is a strong antioxidant (you use approximately 7 grams of ROE to 40 pounds of oil for sufficient antioxidant protection). Not to be confused with rosemary essential oil or rosemary extract. And be careful to purchase a ROE that is *not* in an alcohol or propylene glycol base.
Verb — Seizing is what happens when your soap turns from a lovely pourable "batter" into a unpourable mess! Often it means setting up into a thick "glop" close to medium-thick oatmeal, but if you step away and your soap seizes it can turn into oatmeal cookie dough really fast. Seizing can be caused by some fragrance and essential oils, but some other factors can cause seizing, such as temperatures or oils. Seizing can sometimes be controlled by adding lecithin (a vegetable based emulsifier), warming your fragrance oils before adding to traced soap, diluting scent with base oils, and controlling temperatures.
sodium hydroxide
Noun — The alkali most commonly used to make bar soap. Sodium hydroxide is commonly known as "lye" and is marketed as a drain cleaner under the brand name "Red Devil Lye" in the US.
Stick Blender
Noun — A stick blender is a long, skinny hand-held blender of the type that's used to blend milk shakes, diet shakes, etc. at home. They're usually about $10 at your local Target, Wal-Mart, Kmart, etc. Stick blenders help blend your oils and lye together much better and much *faster* than regular hand stirring can, so they can help you achieve a trace in a few minutes as opposed to 15 minutes, an hour, or longer.
Noun — The state your soap is in when you can see the stirring lines stay for several seconds, or if you dribble a little soap onto the surface, it holds the shape for a few seconds. This is the time to add scent, color, or oils for superfatting (for CP soap). Then pour into your molds.