History of soap manufacturing
In the time of the Gauls, soap was already being used for washing clothes and tinting hair red. The paste was obtained by blending ashes of beech wood and goat suet. It was said to possess certain medicinal virtues.
The Marseilles soap factory set up in the 16th century just after the crusades took the activity a step beyond the handicraft level. At the beginning of the 17th century, production in the Marseille factories was barely sufficient to satisfy demand from the city and the region. The Port of Marseilles even received soap from Genoa and Alicante.
Then the war blocked supplies coming from Spain, and so soap manufacturers in Marseille had to increase their production to be able to supply the north of France and buyers from the Netherlands, Germany and England.
In 1660 there were 7 manufacturers in the city whose annual production was close to 20,000 tons. Under Colbert, the quality of soap produced in Marseille was such that "Marseilles soap" became a byword. At that time the soap was green coloured and was sold in 5 kg bars or 20 kg blocks. In 1786, 48 soap manufacturers were producing 76,000 tons in Marseille. They employed 600 workers and 1,500 convicts loaned by the prison of Arsenal des Galères.
The industry boomed up to the first world war, when shipping became difficult and the local soap manufacturing activity was severely affected. In 1913, production was 180,000 tons, falling to 52,817 tons in 1918.
After the war, soap manufacturing benefited from the progress in mechanization. The quality of the product was due to the use of traditional processes, and production grew, reaching 120,000 tons in 1938. When the second world war broke out, Marseilles was still producing half the national output but the following years were to prove disastrous. Today there are still two manufacturers in activity: Le Sérail and le Fer à Cheval.
Development of a technique
From the end of the 17th century, strict regulations concerning manufacturing enabled soap to acquire the image of a high quality product made from an oil and soda emulsion. The only oil was olive oil and the soda was obtained by burning "soda plants" (marsh samphire and saltwort). This was the first Marseilles soap.
During the 19th century, new discoveries in the field of chemistry and the use of oilseeds made it possible to develop a second Marseilles soap. Natural soda was no longer used in Marseilles, since the first soda manufacturers had introduced the "Leblanc" process at the beginning of the century, in which sea salt was combined with sulphuric acid. Then, ammonia soda produced according to the "Solvay" process was used instead of crude soda.
But the increasing use of artificial soda produced a soap that was too hard and brittle when manufactured with pure olive oil. Blending of oils became the obvious solution. In 1820, the first "grinding" tests were carried out using linseed, and then further experiments were conducted using palm oil and sesame seeds. Groundnut oil quickly became the favourite: as it was colourless it did not affect the colour of the end product, and trade with the East facilitated the supply of top quality groundnuts. The high quality level of Marseilles soap was preserved.
The development of the industry in the 19th century enabled Marseilles soap manufacturers to create highly renowned products such as sesame seed oil based "mottled soap" with a 60% fatty acid content or groundnut or palm oil based "colourless white" with a 72% fatty acid content.
The soap industry gave birth to spin-off industries that contributed to the economic development of the city. The most important one was "stéarinerie"; the manufacture of candles using recycled glycerine.
The different steps for manufacturing soap have undergone very few modifications over the years. They continue to be used today.
- pasting of the oils : emulsion of soap fats and oils with lye. The mixture is brought to the boil in enormous cauldrons.
- "Epinage": removal of impurities from the bottom of the cauldron, carried out three times.
- finishing : the lye is boiled for several hours, then impure sediment is removed again and clean water is used to rinse the remaining impure sediment to the bottom of the cauldron.
- drying in moulds.
- cutting while the soap is still soft.
- stamping : manufacturer's name and brand after solidification.