The words, in the order you meet them
Updated
Defined in the order a maker actually encounters them rather than alphabetically.
Making it
Saponification. The reaction between a fat and an alkali that produces soap and glycerine.
Lye. The alkali. Sodium hydroxide for bars, potassium hydroxide for liquid soap.
SAP value. The mass of alkali needed to saponify a unit mass of a given oil. Different for every oil and different for the two alkalis.
Superfat. The deliberate excess of oil left unsaponified, commonly around 5%.
Lye discount. The same thing expressed as a reduction in alkali rather than an excess of oil.
Trace. The point at which the batter thickens enough to hold a drizzled line on the surface.
Gel phase. The hot, translucent stage a loaf passes through when it is insulated.
Cure. The weeks after cutting during which water evaporates and the bar hardens.
Cold process. Saponification completing in the mold without applied heat. Hot process: cooked to completion before molding.
Rebatch. Shredding and remelting finished soap.
What can go wrong
Seizing. The batter setting solid almost instantly, usually from a fragrance.
Ricing. Grains forming in the batter.
Separation. Oil and soap splitting apart.
Soda ash. The white powdery bloom on the exposed surface.
Partial gel. A darker gelled center with an ungelled ring.
Glycerine rivers. Translucent veining through the bar.
DOS. Dreaded orange spots, from oxidized oil.
Zap test. Touching a cured bar to the tongue to detect free alkali. It stings if there is any.
The determination
Exempt soap. A product meeting both conditions of the soap exemption, outside FDA's cosmetic authority and under CPSC.
Cosmetic. A product intended to cleanse, beautify, promote attractiveness or alter appearance.
Drug. A product intended to treat or prevent disease, or to affect the structure or function of the body.
Syndet. A synthetic detergent bar. It cleans, and it is not soap under the exemption.
Melt and pour. A pre-saponified base you melt and pour. Whether it is soap depends on the base's composition.
MoCRA. The statute introducing cosmetic facility registration, product listing, safety substantiation and adverse event reporting.
INCI. The nomenclature used for cosmetic ingredient declarations.
Selling it
Statement of identity. What the product is, on the front.
Net quantity of contents. How much is in the package.
Principal display panel. The part of the label most likely to be seen at purchase.
Consumer commodity. The category under which the packaging and labeling requirements attach.
Seconds. Cosmetically imperfect, chemically sound bars, sold as such.
Line sheet. The wholesale document listing products, case counts, wholesale and retail prices.