Soap boiler
The soap maker is a craftsman who makes soap from fats , oils and soda . The technique, which has been known since the Sumerians, was introduced to Europe during the Crusades and replaced the washing with wood ash or its lye ( ash lye ) , which had been customary up until then . The first guilds in Central Europe in the 14th century for Augsburg , Vienna and Ulm are recorded .
With the onset of industrial soap production in the 19th century, the handicraft profession lost its importance and only led a niche existence. For some time, however, the craft seems to be experiencing an upturn. Since the turn of the millennium, small soap factories have sprung up in many cities in both Europe and the USA that produce soap using traditional methods and whose products are increasingly being sold by mail order.
The hl. Florian is considered the patron saint of soap makers.
Boiling process
Vegetable or animal fats are used to make soaps . Mainly coconut fat , olive oil , palm oil and animal fats such as tallow , lard or fat from bones are used, which are obtained from animal carcass processing . The fats are melted by the introduction of steam, heated and mixed with solid sodium hydroxide chips or potassium hydroxide solution ( additional heat is released when the hydroxide is dissolved exothermically in water). Potash or soda was also used in the past .
The saponification with sodium hydroxide solution yields solid soap, saponification with caustic potash soft soap . Pure vegetable fat-soda soaps are brittle and brittle, an addition of beef tallow reduces this effect. Waste fats are usually used to make soaps, mostly vegetable oils from hot pressing or extraction with solvents , used deep-frying oils are (in addition to being processed into biofuel ) only processed into soft soaps.
During soap boiling, the fats are broken down into glycerine and the alkali salts of the fatty acids (the actual soap) by heating with the alkali hydroxides mentioned above . The heating for boiling used to take place in open brick kettles. During the so-called “soap tasting” or “soap eating” by the soap makers, the soap was not eaten, but a test of the alkalinity on the tongue. If the alkali content was too high because too much of it was added or the added hydroxide had not yet completely reacted, the soap boiler felt a stinging sensation on the tip of the tongue.
The viscous emulsion obtained when boiling is called soap glue and table salt is added. The emulsion separates by salting out into the floating soap core , which mainly contains the sodium salts of fatty acids, and into lower lye, which mainly contains excess lye, glycerine and the dissolved table salt. The soap core is separated from the lower lye by separation and boiled with plenty of water and a little lye in order to remove the remaining impurities. Renewed salting out then leads to the curd soap . The product is dried in blocks. The blocks are either cut into cuboids or roughly ground. The grist is made into a paste with dyes , fragrances and fillers and calendered on roller mills to trap air and create a beautiful shine. The intermediate product is then rolled out, the resulting strips are extruded or extruded in a hot press , shapes are punched from the pressed strand and simultaneously pressed into toilet soap bars.
Web links
- René Bondt: Soap making. In: Historical Lexicon of Switzerland .