Soap was used for centuries before the invention of shower gel by consumer goods firms. Because it was retro – and a bit too harsh – it got forgotten after that. And here is it making its big comeback thanks to the solid beauty product & zero waste trends. Is that a reason to make a beeline for soap?
A potted history
The first man-made chemical reaction
Way back when, the Egyptians would wash with a kind of soap made of animal fat and vegetable oils mixed with trona, a mineral similar to sodium carbonate. In Gaul, the remains of a mixture of goat tallow, lard and edible oils mixed with ashes have been unearthed. These were what’s known as “soft soaps”, which are not made by boiling.
Around 1000 BC in Aleppo (in modern-day Syria), artisans invented the first hard soap and its manufacturing process. Known as saponification, it is the earliest known man-made chemical reaction. The principle behind it is outlined in the most famous medieval Arabic treatise on medicine, the Kitab al-Mansouri fi al-Tib. It consisted of a mixture of olive oil, plant-based sodium carbonate, bay leaf ashes and water boiled in copper kettles. The resulting blocks of soap would then be dried in the sun for 12 months. This recipe, which is thought to have reached Europe during the Crusades, is the ancestor of all hard soaps.
Aleppo, Castile and Marseille
Two other soaps owe their renown to the trade and upheavals that took place in the Middle Ages: Castile soap and Marseille soap. While the former is a cold-process soap made only with olive oil, what’s known as Marseille soap is a hot-process soap, made with a surfeit of sodium carbonate which is then rinsed off. Contrary to popular belief, the Middle Ages was a period concerned with hygiene and bodycare. The 1688 Edict of Colbert governed the manufacture of Marseille soap. It was to be made from pure Provence olive oil, salt and sodium carbonate shipped directly from the Camargue. However, the use of tallow (animal fat) was strictly forbidden.
With the first colonies, and the scarcity of olive oil, soap works gravitated towards other oils, not least palm and coconut, which made for a white or beige Marseille soap with which delicate fabrics could be washed. In 1906, the wording “Extra pure, 72% oil” was coined to set such soaps apart from the mass-produced ones that were starting to appear. These could be up to 50% water. From the 19th century onwards, mass production of soap went into overdrive and made it a run-of-the-mill commodity. Made from low-grade oils, whose glycerine was drawn off and sold on to other industries, it contained increasing amounts of water and so would dry out the skin. Then came the fat shortage at the end of World War Two, and the advances in chemistry which brought about the advent of synthetic surfactants which are behind syndet and shower gel. These products were cheaper to produce, and met with great success. These synthetic surfactants have come full circle, since they are softened using that glycerine sold on by the soap industry!
How does soap cleanse?
Soap is made from natural ingredients – vegetable oils (olive, palm, coconut etc.) to which an alkaline mineral is added. This is sodium carbonate for hard soap and potash for soft or liquid soap. Possible adjuvants include honey, milk and essential oils. Soap has the power to bind oils to rinsing water, and thus to cleanse! That’s why it’s known as a detergent. Its pH is alkaline: between 9 and 10, while that of the skin is 5.5.
Soap – ecologically sound and economical
Solid soap is more economical
Soap is much more economical than shower gel, being cheaper to buy and lasting a long time.
Liquid soap and shower gel are mainly (80%) water. Since water is a favourable medium for bacterial growth, preservatives have to be added to formulations so that they don’t spoil so rapidly, especially in warm, damp environments like the bathroom. Solid soaps don’t need preservatives, due mainly to their makeup and to a lesser extent their reduced water content. Contrary to what you might often read, soaps are not devoid of water.
Moreover, a good soap made in the proper manner – which doesn’t split or melt – lasts for months, whereas a medium-sized bottle of shower gel (500 ml) seldom lasts more than a few weeks. However, stating that soap costs less in the long run is overstating the case a little. Because as we will see, a genuine good-quality soap is now almost a luxury item. Whereas the soap sold in supermarkets is certainly cheap, but mostly of poor quality.
Long live zero waste
This is in large part what has brought bars of soap back into favour: they generate (almost) zero waste. Those bottles of shower gel – even if made of recycled plastic and recyclable – use tonnes of plastic and thousands of litres of water, and generate tonnes de CO2 through freight transport. There is also uncertainty as to whether these waste items get processed properly by recycling schemes (particularly shower gel tubes which are difficult to recycle). Whereas a bar of soap requires far fewer resources for its production and freight transport. In addition, it’s only the paper or carboard packaging that needs to be sent off for recycling, and not even that if the soap is sold by weight. Soap that’s produced correctly is completely biodegradable.
It’s easy to carry around
The icing on the cake is that a bar of soap is easy to carry around. As long as you dry it thoroughly and pop it in a mesh bag or tin, it can easily travel with you in your toiletry bag, without you having to concern yourself with airline carriers’ weight or volume limits.
The soap of an ideal world and other soaps….
As we have seen, times have changed a lot since the days of Aleppo soap or its descendant from Marseille. Mass-production methods or semi-mass-production methods have fundamentally changed soap’s properties. The kind that you pick up for €2 in the supermarket is nothing like the one for which you’ll pay more than €10 from the last remaining soap makers, who control the entire production process.
Mass production strips soap of its qualities
Consumer goods firms have long gone with “hot-process” or “kettle” production. While this is the method used for Marseille soap, it has been radically changed so as to cut turnaround times, thus also cutting out soap’s properties. So the drying time of soap has gone from one month to one day! Moreover, this process has significant environmental impact when it comes to water and energy usage (the soap gets heated to 100-120°C).
Furthermore, the high temperatures involved mean that more robust ingredients have to be selected. These are themselves produced in ways that are less than eco-friendly, like palm oil. Lastly, soap is rinsed with salt water to get rid of the excess sodium carbonate. This also strips out the glycerine which is beneficial to the skin.
These mass-produced soap blocks are then generally turned into soap pellets. But these days, some 80% of soap pellets are produced in China or Malaysia. Even soaps stamped with the “Marseille soap” wording are produced mainly in Turkey or China.
These soap pellets then get sent to “semi-artisan soap works”, which are not actually soap manufacturing facilities, but processing works. There the soap is extruded into bars and merely perfumed, coloured, moulded and stamped, and sometimes a little oil is added. So how can you tell what’s what? Well, if a bar of soap melts quickly or splits over time, it’s not a good one. If it goes soft very quickly, it contains too much water and has not been dried for long enough during the production process. Its “core” has not had time to harden.
You can nonetheless find good hot-process soaps, not least artisan Marseille and Aleppo soaps. These are made from high-quality raw materials, taking the time needed, and enriched with glycerine or oil during the production process. Hence their being referred to in French as surgras (fat-enriched). You have to check the production location, and go ahead and quiz the sales assistant.
Cold-process saponification – preferable but a rarity
As its name suggests, cold-process saponification is carried out without a boiling phase. But this method can’t be scaled up for mass production, because it requires raw materials of excellent quality. It also has a long turnaround time, as it takes more than a month to produce bar of soap. The oils and sodium carbonate are mixed together and emulsified before being poured into a mould. Saponification sparks off an exothermic reaction that brings the temperature to 60-65°C, which retains the oils’ properties. Then comes the “curing” phase, meaning that the soap is left to rest for 4-5 weeks. During this time it dries out and stabilises, since saponification continues until such time as one of the reagents (sodium carbonate or oil) is all gone. Glycerine is produced naturally during this process, which doesn’t take much water or energy. The soap is biodegradable, and has both detergent and moisturising properties since it is around 10% glycerine. It also contains insaponifiables (which as their name suggests are ingredients that don’t get turned into soap). These are vitamins, terpenes, squalene and phytosterols, etc. These have nourishing, softening, protective or antioxidant properties. The problem is that you won’t find this type de soap in mass retail, because it is made by small-scale producers and sold at more than €5 per bar.
Is soap really good for the skin?
Is there a single person who hasn’t been advised to wash with good Marseille soap by a dermatologist? What do you say to this skin specialist, who has perhaps forgotten that soap is by definition alkaline (or basic), and therefore at odds with the skin’s pH? How can you tell? Well, if you use basic soap (in more ways than one) in the shower, it will leave your skin squeaky. It will be sticky rather than strokable, and can become rough if you don’t use body lotion regularly enough.
That’s why soap is said to strip the skin. It degrades the hydrolipid film that protects the skin, causing it to dry out. The problem can only be bypassed by using soaps whose glycerine content has been preserved.
But even then, be aware that fragrance and essential oils, even if rinsed away, can cause reactions in some people with very sensitive skin. As for those with broken skin or atopic eczema, whereby the skin’s barrier is compromised, they should be particularly vigilant when it comes to soap ingredients.
So should we all be going back to soap? Yes, but only the genuine article, made in the proper manner as it used to be in the olden days. This involves a long turnaround time and drying phase and high-quality, pure virgin oils. As opposed to mass-produced soap, which is full of water and stripped of its glycerine.
The problem is that it’s hard to tell the genuine article apart from a mass-produced soap. This is because even those stamped with the “Made in France” wording are, in fact, merely processed in France! Otherwise, opt for the surgras soap found in pharmacies.