Or perhaps phrased another way: How do they make foaming hand soap foam? Is it just that it has more water in it?
My guess is more air. Bubbles.
o, that WAS a guess.
I’ve wondered about this. I like the foaming soaps they’re using in public restrooms. I can wash quicker with them because they’re already lathered up, as opposed to a thick liquid. I’ve wondered whether they have some sort of manual air pump, or a pressurized vessel, some chemical reaction or what. Maybe just a big bag of foam?
They have a pump that forces air into it to make the foam. I have a refillable one at home and the instructions that came with it say to put 1 part normal liquid soap to 4 parts water. So another difference is the foaming soaps contain a lot more water.
If you mean the kind of soap that comes out the nozzle as foam, I think that is because of the dispenser, which adds air to a mixture of diluted soap.
That said, some basic detergents foam more then others. The cheapest liquid detergent, which is a staple ingredient in shampoos, and other liquid soaps (and even in toothpaste) is Sodium laureth sulfate, or SLS. That one creates a lot of foam in watery solutions, so much so that when it is used in products where foam is a nuisance (like toothpaste or some types of dishwasher liquid, where foam clings to the clean glasses) it requires that an anti-foam substance is added.
ETA: a lot of the liquid soap that comes out of dispensers is also watered down, but thickened up with a thickening agent. That made me feel less bad about washing globs of it down the sink. But I agree that foamed up soap is more efficient to use.
It the SDS, or Sodium dodecyl sulfate (sometimes called sodium lauryl sulfate). It’s a pretty common detergent.
Here is a wiki -
You beat me to it…
We just buy a disposable foaming soap dispenser at the store, and when it runs out, refill with liquid soap + water, rather then throw it away. In the bathrooms, it’s shower gel, in the kitchen it’s dish soap. The dish soap mix makes it really easy to clean just 1 dish or pan, without getting way to much soap.
Thanks guys. It seems that as usual I am guilty of phrasing my question poorly. Of course I *get *foam. I understand that air is injected.
What I was wondering is the difference between regular liquid soap and the kind in dispensers that inject air into it creating the foam.
**gazpacho **has confirmed my hunch that you don’t just use regular liquid soap, but instead must water it down - and has provided the ratio.
My fault for phrasing it poorly.