bars of natural soap

How Soap Works?

bars of natural soap

How Does Soap Work?

We are all aware that soap has the ability to cut through grease producing a cleaner, more sanitised result – but how? How does soap work and what is the science behind it?

Soap is a very effective hand and body cleanser. However, not only does it cleanse, it also sanitises by destroying viruses and bacteria. Read on to discover how soap works.

Water & Oil Doesn’t Mix

The purpose of washing is to remove the external layer of oils and fats that carry germs and rinse them away from the surface of the skin. Oils and fats are known as ‘nonpolar’ compounds, which means they cannot be dissolved by water alone. This can only be done if we wash with something that can attach to fat molecules. Soap works by mixing with both oil and water.

oil and water mixed


When greasy dirt or oil is mixed with soapy water, the soap molecules arrange themselves into tiny clusters called micelles. The water-loving (hydrophilic) part of the soap molecules sticks to the water and point outwards, forming the outer surface of the micelle. The oil-loving (hydrophobic) parts stick to the oil and trap the oil in the centre. The soap molecules arrange themselves to become a barrier, trapping the oil in the centre. As the soapy water is rinsed away the greasy dirt is also rinsed along with it.

Soap Washes Everything

Therefore, when you wash with soap and water, the soap molecules grab onto the fat molecules and pull them off the skin into the rinse water. When you rinse the skin, the fat and germs are removed from the skin.

Thus, the main reason why soap works to cleanse and sanitise, is that it literally washes everything off the skin.

Washing hands with water and soap

Soap works also effectively at combating a virus. This is because soap molecules attach to the fatty molecules within a virus and tear it apart.

Washing with Hot vs. Cold Water

Ever wonder why it is easier to clean dirt and grease in hot water rather than cold water? This is because the oils and fats soften or melt in hot water, which allows them to attach more readily to the hydrophobic end of the soap molecule. In turn, this then makes it easier to rinse away.

hot water coming out of a tap

Soap is a Surfactant
Soap works as a natural surfactant. A surfactant is any substance that reduces the surface tension of a liquid in which it is dissolved.

Most cleansing products are based on surfactants. Surfactants not only reduce the surface tension of the water but the unique way they are constructed (with one hydrophobic end and one hydrophilic end) makes them compatible with both oils and water. This property is what makes them ideal for cleansing.

Soap bubbles in hand

When surfactants lower the surface tension of water, they effectively make the water molecules more slippery. This makes them less likely to stick to themselves and more likely to interact with grease and oil.

Natural soap doesn't require synthetic additives to create lather or to clean because natural soap is a natural surfactant. So not only make does it make great bubbles and lather, but it also helps clean and remove oily dirt from your skin – naturally!

You can also watch an informative video of how soap is made here.

Shop Now! - Shop our collection luxury soaps and washes from The English Soap Company now. 

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