What is Cold Process (CP)?
The process of mixing a fat (oils and butters) with a salt (sodium hydroxide or also known as lye). The result is a chemical process called saponification, where the oils and the lye change their composition and the result is soap. There are dangers when making cold process soap. You will need to refer to lye safety before getting started. With the proper safety gear and the right ingredients and tools you can make amazing soaps.
Cold process can be made with skin nourishing oils and butters. Glycerin naturally occurs in cold process soap.
If you are a beginner soap maker, we recommend starting with our melt and pour soap recipes. These use the very safe Crafter’s Choice Melt and Pour Soap Bases, and allow you to creatively make soap without using dangerous chemicals. Melt and pour soap is a glycerin soap base that can be melted and poured into a mold. You can add scents and other additives.
Cold Process Soap Terminology
: Any ingredient that is added to the soap that is not part of the soap itself is considered an additive. Additives may include herbs, salts, clays, vitamins, seeds, preservatives, extracts, etc.Caustic
: A caustic is a corrosive substance that burns or destroys organic tissue by chemical action. It is typically used to describe the action of an alkaline base. Lye is a caustic substance.Cold Process Soap (CP)
: The process of mixing a fat (oils and butters) with a salt (sodium hydroxide or also known as lye). The result is a chemical process, called saponification, where the oils and the lye change their composition, and the result is soap. Glycerin naturally forms in cold process soap.Colorants
: Colorants used in cold process soap can be clays, micas, oxides, herbs, and spices.Cure
: Cure refers to “curing” soap by leaving soap out in a well circulated room, so the moisture evaporation can occur. This is generally done 24 to 72 hours after the soap has been prepared in its molds. It can be done by taking the soap out of its molds and leaving it in full shape or cutting it. If soap is placed on a flat surface, it will need to be rotated every few days. It is preferable that you place the soap on a stainless steel rack, so the soap can have plenty of ventilation. Curing can take anywhere from 4 to 6 weeks. This is when the soap is at its mildest.DOS (Dreaded Orange Spots)
: DOS appears as brown or orange spots on your soap. This can happen if you super-fatted too much. It may be a sign of rancidity. It is seen in soaps that use higher amounts of vegetable, sunflower, and canola oils.Essential Oil (EO)
: EO refers to Essential Oils. Essential oils can be used to scent your soap or other body products. Essential oils are steam distilled or chemically distilled from plants. This is a more natural way to scent your soaps. They are volatile oils.Exfoliants
: Exfoliants are additives that make the soap scrubby, and make it exfoliate the skin. Some exfoliants used in soaps include, but are not limited to, apricot kernel seeds, blueberry seeds, ground walnut, powdered coconut shell, mustard seeds, cranberry seeds, poppy seeds, etc.Fixed Oils
: Fixed oils are oils that can be heated to a high temperature without evaporating. Olive oil, palm oil, and coconut oil are some fixed oils that are commonly used in soap making.
: Flash point is the lowest temperature at which the vapors of a liquid will ignite in the presence of an ignition source. It is important to know your flash points of your essential oils and fragrance oils. Fragrance Oils (FO)
: FO refers to Fragrance Oils. They can be used to scent your bath and body products. Fragrance oils are synthetic, but may be diluted with a carrier oil or propylene glycol. Some examples of carrier oils are vegetable oil, mineral oil, almond oil, etc. FO’s can be custom blended to make your soap smell like the ocean, or even sliced bread.Gel Phase
: Soap has reached its gel phase when the soap batter temporarily becomes a warm, transparent gel and slowly returns to being opaque, more solid, and having a cooler temperature. Not all soaps go through a gel phase. HP
: HP refers to Hot Process. Hot Process soap making is when you “cook” cold process soap to speed up the saponification process. This is usually done in a crockpot or oven. HP soap bars can be used as soon as they have cooled, but would benefit from a longer cure.Lye
: Lye (Sodium Hydroxide, Caustic Soda) is an alkaline or base used in making cold process soap bars. Lye is extremely dangerous and should always be respected. Always use protective gear, such as gloves, goggles, face shields, long sleeved shirts and closed toe shoes. Lye will react to certain metals and wood. It is important to use only stainless steel, plastic or silicone- DO NOT USE GLASS. The lye solution, over time, can cause the glass to shatter.Lye Discount
: Lye Discount is the practice of withholding lye from a soap recipe. Use a Lye Calculator to determine the amount of lye needed to completely saponify the fats. Then, determine the percentage of Lye Discount you want to use, and withhold that percent from the recipe. For example, if you want a 5% Lye Discount, only use 95% of the calculated amount of lye. The other 5% is withheld from the recipe.MSDS
: MSDS refers to Material Safety Data Sheet. An MSDS contains pertinent information related to the following safety categories for a specific material: Manufacturer or vendor information, chemical composition, hazards and potential health effects, first aid measures, firefighting measures, spill measures, handling and storage, exposure and protection, physical and chemical properties, stability and reactivity, toxicological information, environmental information, disposal considerations, transportation information and regulatory information.pH
: pH is the scale used to measure the acidity or alkalinity of a chemical, typically dissolved in water. The scale goes from 0 (Very Acidic) to 14 (Very Alkalinic/Basic). pH of 7 is neutral. Lye is a corrosive chemical used to make natural soap, and it has a pH of 14. Water, also used to make soap, has a pH of 7. Cured soap should have a pH within the range of 8 to 10.Rebatching
: Rebatching is the process of melting down existing soap to create new soap. This process is used when your soap didn’t quite come out exactly how you wanted it, so you have the chance to create something new out of the “bad” soap. By melting down the soap, you can add additional oils to correct the lye imbalance, or add exfoliants or additives.Ricing
: Ricing is when your soap looks like it has pieces of rice in it, caused by the fragrance oil. It can be vigorously stick-blended out of the soap to correct the problem, but that doesn’t always work. Ricing will only affect how your soap looks. Fragrance oils that cause rice are usually movers. Some examples of these FO’s are florals and spices.RT
: RT stands for room temperature.RTCP
: RTCP refers to Room Temperature Cold Process. It is nearly the same as cold process soap making, except for one difference. Instead of heating the ingredients to a specific temperature, the ingredients are left to cool until they reach room temperature. RTCP soap making can take a full day, so it’s better to prepare the lye hours before.
: Sap Value refers to Saponification Value. An oil’s Sap Value is the number of milligrams of lye required to completely saponify one gram of a specific fat. Use a Soap Calculator to determine an oil’s Sap Value. Try using the WSP Lye Calculator
: Saponification is the chemical process of an alkaline/base (Sodium Hydroxide or Potassium Hydroxide) reacting with the fatty acids to produce soap.Seizing
: Seizing is when soap quickly changes from a liquid to a very thick solid that is hard to work with. It can be caused by FO’s that are added or the temperature of your soap ingredients. Once a soap has seized, it is irreversible. You must put the soap into a mold immediately, and press it down so that it will hold its shape. If your batch of soap seizes, you can use the soap for a rebatch.Soap calculator
: A soap calculator is also known as a saponification calculator or lye calculator. It is used for calculating how much lye is needed in proportion to the amount of oil or fat you are using. It is very important that you always run your recipes through a soap calculator to insure the safety of your product. If too much lye is used, you will have a lye heavy bar, and it will be harsh or dangerous to your skin. It is always important to measure your oils and lye precisely.Soda Ash
: Soda Ash is the whitish-grey substance that can appear on the surface of your soap when it is exposed to air. It normally appears within the first 24 hours of being made. The ash is not harmful, rather it adds a rustic appearance to your soaps. It usually washes off after the first few uses of the soap. To prevent Soda Ash, you can place plastic wrap over your molds or lightly spray your soap with isopropyl alcohol every hour, for the first few hours.Superfat
: Superfatting is the process of adding excess oils/fats to your soap recipe that is beyond amount calculated to completely saponify with the lye. Most soap makers prefer 5% superfat, which means 5% more oils are added to the recipe.Trace
: Trace is when the soap batter thickens and can leave a distinguishable trail on the surface of the soap better.Volatile
: A volatile substance is a substance that readily becomes a vapor at low temperatures. Most essential oils are highly volatile.