Soap Making Glossary: 22 Terms Explained
The words that show up in soap making specs, reviews and how-to guides, explained without jargon. Open any term for the full explanation and what to look for when buying.
- Castile soap
- Cold process soap made almost entirely from olive oil, known for a mild, gentle, long-curing bar.
- Read more about castile soap
- Cold process
- Making soap by mixing oils and a lye solution at moderate temperature, then curing for weeks.
- Read more about cold process
- Cure
- The multi-week drying period after cold process soap is made, which hardens bars and extends their life.
- Read more about cureRelated: Best Curing Racks for Handmade Soap
- Embed
- A small pre-made soap shape suspended inside a larger bar for a decorative, layered look.
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- False trace
- A batter that appears to have thickened to trace, caused by solidifying butters rather than saponification.
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- Fragrance oil usage rate
- The maximum percentage of a fragrance oil a supplier lists as appropriate for a given product type.
- Read more about fragrance oil usage rateRelated: Best Fragrance Oils for Handmade Soap
- Gel phase
- A heating stage inside curing soap that can deepen colors, which some makers encourage and others avoid.
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- Hot process
- Cooking soap batter after trace until saponification finishes, shortening the wait before use.
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- Insulation
- Wrapping or boxing a freshly poured soap mold to hold in heat and encourage a full gel phase.
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- Lye
- Sodium hydroxide or potassium hydroxide, the caustic alkali that reacts with oils to make soap.
- Read more about lyeRelated: Best Lye for Soap Making
- Lye calculator
- A tool that calculates the exact lye and water amounts a soap recipe needs based on its oils.
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- Melt and pour
- A pre-made soap base that is melted, colored, scented and poured, with no lye handling required.
- Read more about melt and pourRelated: Best Melt and Pour Soap Base
- Mica
- A finely ground mineral powder used to color soap, prized for its shimmer and wide color range.
- Read more about micaRelated: Best Mica Powder for Coloring Handmade Soap
- Ricing
- Small solid clumps that form in soap batter when a fragrance oil reacts badly with the recipe.
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- SAP value
- A number describing how much lye is needed to fully saponify one gram of a specific oil or fat.
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- Saponification
- The chemical reaction between fats or oils and lye that produces soap and glycerin.
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- Soda ash
- A powdery white film that can form on cold process soap, usually just a cosmetic issue.
- Read more about soda ashRelated: Best Soap Planers for Clean, Even Bars
- Superfat
- Extra unsaponified oil left in a soap recipe on purpose, usually around 5 percent, for a milder bar.
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- Swirl
- A decorative technique that blends two or more soap colors into patterns like ripples or feathers.
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- Titanium dioxide
- A bright white mineral pigment used to whiten soap or lighten and adjust other colorants.
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- Trace
- The point where soap batter has thickened enough that a drizzle leaves a visible trail on top.
- Read more about traceRelated: Best Stick Blenders for Soap Making
- Water discount
- Using less water than the default amount in a lye solution, to speed unmolding and shorten cure time.
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