That’s why wood feels softer after treatment with soap.

Short answer

In an independent laboratory test, old, dirty wood was perceived as significantly softer after treatment with soap compared with untreated wood. With new wood, however, the panel could not perceive a corresponding difference in the same way. The report presents the observation but does not investigate why the effect occurs.

What did the laboratory show?

After cleaning and treatment, five people assessed the feel of the wood surfaces by comparing them with untreated reference samples. For old wood, the treated surface was judged to be significantly softer, while new wood did not show an equally clear change.

It is important to distinguish between what was observed and why it happens. The laboratory’s task was to evaluate the result, not to establish the underlying mechanism.

Our technical explanation

The explanation is that superfatted soap works differently from many ordinary cleaning products.

During the production of superfatted soap, a small amount of natural fatty acids remains after saponification. These help dissolve dirt during cleaning but may also leave behind a very thin protective layer on the wood surface after the water has evaporated.

On older, dried-out wood, where the surface has often become rough due to weather, dirt, and repeated cleaning, this may contribute to the wood being perceived as:

• softer to the touch,
• less rough,
• more pleasant to the touch.

On newly impregnated wood, there is an intact surface layer from the factory impregnation process, which explains why the panel did not perceive a corresponding difference in the laboratory test. The factory impregnation is still present. The difference therefore becomes clearer when the outermost layer of the impregnation has worn away after people have walked on the surface, used it, or exposed the wood to weather and wind. This is consistent with the test results, but the actual cause was not verified in the report; it is our technical interpretation based on how impregnated wood works.

Summary: The laboratory verified that old wood was perceived as significantly softer after treatment with soap. The likely explanation is that superfatted soap not only cleans but also leaves behind natural fatty acids that make the wood surface more pleasant, but this mechanism was not investigated in the laboratory test.
Factory surface treatment/impregnation disappears after some time outdoors, after which the wood fibers are exposed and more receptive to treatment with soap.