Soap Making Glossary

Every term you'll meet in a soap recipe, in plain English.

C

Cold process: Making soap by mixing lye solution and oils at moderate temperatures, pouring into a mold, and letting saponification finish over a day or two before a multi-week cure. More about cold process
CPOP: Cold process oven process: putting freshly poured cold process soap in a warm oven to force gel phase for brighter color and faster unmolding. More about cpop
Cure: The weeks after cutting when water evaporates and the bar hardens and becomes milder. Most cold process soap cures four to six weeks. More about cure

DOS: Dreaded orange spots: small orange patches caused by oils going rancid, often from old oils, high superfat or humid storage. More about dos

False trace: Batter that looks thickened because solid fats are cooling, not because it has emulsified. It separates later. More about false trace

Gel phase: A stage where soap heats itself and turns translucent from the center out. Gelled soap is brighter and firmer sooner; ungelled soap is more matte. More about gel phase

Hot process: Cooking soap batter with added heat until saponification completes, so bars are safe to use sooner, with a rustic texture. More about hot process

KOH: Potassium hydroxide. The lye used for liquid and soft soaps. More about koh

Lye: A strong alkali (sodium or potassium hydroxide) that reacts with oils to make soap. No lye remains in properly made, cured soap. More about lye
Lye concentration: Lye's share of the lye solution by weight. At 33%, one part lye dissolves in two parts water.

Melt and pour: Ready-made soap base you melt, customize and pour. No lye handling. More about melt and pour

Rebatch: Grating and remelting finished soap, usually to rescue a batch or add delicate ingredients. More about rebatch
Ricing: Batter forming small rice-like lumps, usually triggered by a fragrance oil. More about ricing

SAP value: The amount of lye needed to fully saponify one gram of a given oil. More about sap value
Saponification: The chemical reaction between fats and lye that produces soap and glycerin. More about saponification
Seize: Batter thickening suddenly to a solid mass, usually from a fragrance or too-hot ingredients. More about seize
Soda ash: A harmless white film on the surface of new soap, formed when unreacted lye meets carbon dioxide in the air. More about soda ash
Superfat: The percentage of oils deliberately left unsaponified, which makes soap milder and adds a safety margin. More about superfat

Trace: The point where oils and lye solution have emulsified and the batter leaves a trail on its surface. More about trace

Water discount: Using less water than the default, which speeds unmolding and reduces soda ash but shortens working time. More about water discount