We often receive calls from customers concerned that their Traditional Savon de Marseille looks different to the last bar they bought.
It may be lighter or darker in colour. It may slice beautifully or crumble when cut. Or, perhaps most commonly, there is the concern that the soap has somehow "gone off" because a white bloom or crystals have appeared on the surface.
These are entirely normal characteristics of traditional Marseille soap.
Made from vegetable oils in large cauldrons using a process that has changed remarkably little over time, the recipe is simple, the ingredients are agricultural products rather than laboratory-made raw materials. The olive oil used this year is not identical to the olive oil used last year. Harvests differ, growing conditions differ, the environment in Marseille during production and drying differs, as it does once it arrives with us in the UK.
As a result, batches can vary in colour, texture and hardness.
Some bars are a lighter olive green, whilst others are noticeably darker; some batches are firm and dense, others are softer or more brittle. We often find the greatest variations occur during periods of particularly hot or particularly cold weather in Marseille or the UK where environmental conditions influence how the soap dries and matures.
Traditional Marseille soap is also a living product. Long after it leaves the cauldron, it continues to dry, mature and respond to its environment. One of the most common questions relates to the appearance of a white bloom, haze or small crystals on the surface of the soap.
This natural phenomenon is known as salt efflorescence.
As the soap continues to dry, naturally occurring salts can migrate towards the surface where they become visible. Although the appearance can be surprising if you have not seen it before, it is not mould, it is not damaged or contaminated and it is not a fault with the soap.
In the UK, we most commonly notice this on cubes and bars during periods of very cold weather in our warehouse, or when fresh batches arrive from Marseille following prolonged periods of hot weather.
At the time of writing, Marseille is experiencing exceptionally high temperatures. In fact, one of our savonneries has already advised us that our next shipment is likely to show more salt efflorescence than usual because of the conditions during production and drying.
This is entirely normal for a proper soap, traditionally made from vegetable oils and free from the preservatives, stabilisers and processing aids often used to create a more uniform product. The soap underneath remains exactly the same. Its quality, safety, cleaning performance and longevity are completely unaffected. The white salts can be wiped away with a damp cloth, washed off during use or simply left alone.
These variations are often most noticeable in the traditional 2kg Marseille soap blocks.
For centuries, families across France have bought large bars and cut them into smaller pieces for use around the home. Depending on the batch, some bars cut very easily whilst others can be more challenging and may crumble when sliced.
We have discussed this directly with our savonneries and their advice mirrors our own experience. If you intend to divide a large block, it is usually easier to do so whilst the soap is relatively new. A cheese wire or a knife warmed in hot water will often give the best results.
If a little crumbling occurs, don't throw it away.
The pieces are exactly the same soap and can be used for hand washing, laundry, stain removal, mopping floors and general household cleaning. Many customers also place pieces in drawers, wardrobes, linen cupboards and storage boxes, where Marseille soap has traditionally been used to help keep stored linens fresh and discourage moths.
For us, these variations are simply part of traditional soap making.
No two batches of Traditional Savon de Marseille are ever completely identical. Given the simplicity of the recipe, the natural variation in the oils and the changing conditions in which the soap is made, we would be far more surprised if they were.