Eli5: How does soap get so sudsy and bubbly, given that it starts as either a thick liquid (like shampoo) or a solid (like a bar of soap)?
In: Chemistry
All the science-y stuff aside, soap has foaming/suds agents added to it.
https://www.stephensonpersonalcare.com/blog/2018-07-31-what-makes-shower-and-bath-products-foam
VERY ELI5: Soap is kind of perpetually falling apart and being kept from falling apart. In its dry bar state, there’s not much you can do to it to change its state. You can pulverize it and it’ll still be dry bits of soap. Add the secret ingredient (water), it loses its “keeping it from falling apart” factor dryness) and becomes a surfactant to pretty much anything that’ll stick to it (most things)
There are better ways to explain it, I’m sure.
[Explained better here](https://www.youtube.com/watch?v=ZOKAoNbJkSg)
Soap is working by surrounding dust and durt (which is when you’re cleaning something is including yourself mostly fat) small structures with a lipophilic tail and a hydrophilic head are making a bubble around the fat part wich is in a way becoming hydrophobic so it make it easier to clean. The buble is just those molecules surrounding a bubble of air on both side with the hydrophobic part on the outside so it don’t blend with water.
Soap doesn’t really need to bubble or be foamy. Companies add it to make if feel like its cleaning better. Bubbles have nothing to do with cleaning.
The common ingredients that make soap foam are sodium laureth sulfate (SLES), sodium lauryl sulfate (sometimes referred to as sodium dodecyl sulfate or SLS) and coco-glucoside.
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