Definition
Superfat
The proportion of oils in a soap recipe deliberately left unsaponified, so that some oil remains free in the finished bar rather than being turned into soap. It is expressed as a percentage of the oil weight, and cold process soap commonly uses 5 to 8 percent.
Superfat makes a milder, more conditioning bar and provides a safety margin against a small weighing error. Too much leaves a soft, greasy bar that does not lather well.
Tools that use this term
Soap Batch Size Calculator
Turn a bar count and bar weight, or a mould volume, into the oil, water, fragrance and lye weights a soap batch is built from.
Soap Mold Volume Calculator
Volume of a rectangular, cylindrical or loaf soap mould in cubic inches and millilitres, and the batter weight it holds at 0.4 ounces per cubic inch.