{{Spoken Wikipedia, En-Rebatching.ogg, date=2006-06-23
Rebatching, or hand milling, is a
soapmaking
Soap is a salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually used for washing, b ...
technique used by hobbyists and artisan
soapmakers. The commercial equivalent is
French milling.
In rebatching, commercially purchased or previously made soap (a ''soap base'') is shredded or diced finely and mixed with a liquid, into which the soap shreds begin to dissolve. It is then heated at a fairly low temperature until the mass is more or less homogeneous. When it becomes translucent and reaches a thick,
gel-like consistency, it is spooned or piped into molds and allowed to harden.
Soapmakers frequently use rebatching as a way of adding substances that could not withstand the high temperatures or caustic chemical environment of
cold process or
hot process
Soap is a salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually used for washing, b ...
soapmaking, such as certain
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...
s (for example, those with a very low
flash point
The flash point of a material is the "lowest liquid temperature at which, under certain standardized conditions, a liquid gives off vapours in a quantity such as to be capable of forming an ignitable vapour/air mixture".
The flash point is somet ...
). The choice of liquid affects the character of the finished soap; milk is frequently used to give the soap a smooth, creamy consistency. Rebatching can also be used as a way of salvaging soap that cracked, curdled or separated while being made.
As with the
melt and pour process, rebatching does not necessarily involve
saponification
Saponification is a process of cleaving esters into carboxylate salts and Alcohol (chemistry), alcohols by the action of aqueous alkali. Typically aqueous sodium hydroxide solutions are used. It is an important type of alkaline hydrolysis. When the ...
, and as such it is a misnomer to refer to it as soap-"making".
Soaps
Handicrafts