Why does shower gel foam? And does it matter?

Shower gel foams because the cleaning ingredients in it, called surfactants, trap air when you work them with water. The foam is a side effect. It is not a measure of how clean you are, and a shower gel that foams less is not cleaning less.

Quick answer

• The cleaners in shower gel have one end that likes water and one that likes oil and dirt.
• They wrap round dirt and oil so water can carry it away.
• Foam is air trapped in a thin film of those same cleaners.
• Lather feels satisfying but it is not the job. The rinse is.

How a cleaner works

The cleaning ingredients in a shower gel are shaped like a tiny tadpole. The head is attracted to water. The tail is attracted to oil and dirt. When you wash, the tails grab on to the dirt and oil on your skin and the heads face outwards into the water. The dirt ends up wrapped in a ring of cleaner.

Where the foam comes from

The same cleaners also sit at the surface of a bubble. Work the gel with water and you push air into it, and the cleaners form a thin skin around each pocket of air. That is lather.

Does more lather mean cleaner?

No. Plenty of effective cleaning ingredients foam only a little. Some strongly foaming ones are used mainly because people like the look and feel of a big lather. It is a habit more than a requirement.

What does matter

The rinse. The cleaner has wrapped the dirt, and the water carries it away. If you do not rinse properly, you leave some of it behind.

What this means for you

• Use a small amount. Two pumps is enough.
• Do not chase lather by adding more gel.
• Rinse until it is gone, then a few seconds more.

FAQ

Why does my shower gel not foam much?

Different cleaners foam differently. Less foam does not mean it is not working.

Is a big lather better?

It feels better. It does not clean better.

Does SLS-free foam?

Yes, it just uses other cleaners, and the lather can feel a little different. See what SLS free means.

GUYSTUFF Original uses a plant-derived cleansing system and lathers as you would expect. Have a look.