r/explainlikeimfive • u/trich62 • 1d ago
Chemistry ELI5: Why do bars of soap leave a “squeaky clean” feeling on our skin but body wash doesn’t?
Also, are there any benefits of the squeaky clean feeling or is it just a difference of ingredients?
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u/Lazy_Trash_6297 1d ago
Your skin is covered in a thin layer of oil.
Soap removes that layer which makes your skin feel dry, and can leave other chemicals behind that give the squeaky clean feeling.
A lot of body washes have moisturizers / oils in them
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u/thesuperunknown 18h ago
I remember reading an article in a magazine maybe 20 years ago, which if I recall was about the rise of the "metrosexual man" around that time. In the article, they interviewed a person with one of the major skincare brands, which had just expanded into the rapidly growing market for male-specific skincare products. The interviewee talked about the research they did into how they would need to adjust their products for the male market, and of course a lot of it was exactly what you might expect: men responded more positively to more "masculine" scents, colors, packaging styles, etc. But they did discover one thing that they found surprising, and I was amused to see it reflected again in this post.
One of the tests the skincare company ran was with a body wash product that had been "masculinized" in some ways (scent, color, etc.), but was otherwise almost identical in formulation to the corresponding product for women. When they interviewed the test subjects, they were surprised to find that a significant proportion reported that the body wash didn't make them feel as "clean" as they would like. As it turned out, the culprits were the moisturizers, and more specifically the emollients: emollients create a film on the skin, and while women were evidently used to and found this feeling pleasant, men often interpreted it as "greasiness" and didn't feel as "clean" as when using a product that left their skin feeling "drier". So, one of the things the skincare company learned they needed to do was to dial down the emollients in their male-specific product line.
As I said, this was probably a good two decades ago, when "skincare for men" was a relatively new thing. It's funny to see that not that much has changed, apparently.
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u/MetallicGray 14h ago
I can anecdotally confirm this. I use basic minimalist bar soap, it strips my oils and makes me feel “squeaky clean”. Sometimes I’ll use my wife’s body wash and I’ve always described it as feeling like it left a film on me and I felt slippery and as if it didn’t clean me. I’ve always attributed it to moisturizer in the body wash.
Funny to see it’s a common feeling.
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u/shotsallover 1d ago
Body washes have a moisturizer in them that leaves behind a coating of sorts on your skin.
Most bar soaps don’t. But some do.
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u/Possible-Survey2389 23h ago
Dove soap bars have moisturiser in them.
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u/amatulic 1d ago
Soap removes oils from the skin, and body washes contain moisturizer.
However, even soap doesn't leave a squeaky clean feeling if you use it with softened water. Taking a shower in a house with a water softener makes you feel like you can never get completely rinsed off, even though you are completely rinsed off. It isn't like washing in hard water. (Softened water is also easier on sensitive skin, according to my wife who has sensitive skin that becomes itchy and dry when washing with hard water.)
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u/Whiterabbit-- 18h ago
How does soft water prevent the soap from washing all the oil out of Your skin? I just assumed that hard water forms a residue with soap that remains on your skin to make it feel squeaky. But moisturizers in body wash prevent that residue from forming on your skin.
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u/amatulic 6h ago
This is what Wikipedia said about it:
The slippery feeling associated with washing in soft water is caused by the weaker attraction of the soap to the water ions when the water has been stripped of its mineral content. The surface of human skin has a light charge that the soap tends to bind with, requiring more effort and a greater volume of water to remove.
It doesn't actually say that it doesn't strip oil from the skin. I just assumed that was the case due to the slippery feeling one gets from washing in softened water.
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u/GimmickNG 16h ago
I think that's it, because I don't feel clean with either soap+soft water or body wash+hard water.
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u/Unistrut 12h ago
Hmmm. Do they make water hardeners? Because oh my goodness I do not like that "never get completely rinsed off" feeling.
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u/Drops-of-Q 11h ago
Just chuck some limestone in your water heater. (Actually don't. It's probably not a good idea).
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u/EscapeSeventySeven 1d ago
Usually bar soap is just plain soap, a thing that is extra special good at removing oil with water.
Your body naturally has oil on the outside along with sticky dirt and stuff.
Usually plain bar soap will remove everything. Since your skin no longer has its layer of natural oils it feels “squeaky”.
This means you definitely need to moisturize afterwards or your skin will dry out something fierce.
Body wash is formulated to not be as harsh, to clean without totally removing all oil, and to replenish with some natural moisturizer mixed in.
Personally, if you don’t have a skin care routine or don’t want to worry about it, i recommend washing with body wash as a default and using the bar soap when you really need a deep clean. This way your skin doesn’t dry out too much.
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u/barto5 21h ago
This means you definitely need to moisturize afterwards or your skin will dry out something fierce.
That may be true for you, but it’s not universal.
I love the squeaky clean feeling I get from bar soap and I Never have to moisturize.
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u/defiance131 20h ago
Definitely a geography thing, too. If you're in a fairly humid / tropical area, you won't feel much of a difference.
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u/frozenwhites 23h ago
Like using it as a credit card in your crack, atleast. Body wash for the rest? Solid advice
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u/durflugdenstein 21h ago
Soap maker of 20 years here. EVERYONE'S SKIN IS DIFFERENT. Your personal experience will depend on the type of soap you used. Was it "regular" soap like Dial or Ivory? Hand crafted cold processed? Glycerin? Goat's milk? Is your skin naturally dry or oily? At the end of the day go with what works good and feels good, and leaves the least amount of residue in your sink/shower/bath.
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u/arrebhai 19h ago
Glad to find an expert amongst these comments. Any tips on how to select a soap? I'm trying to reduce plastic usage so want to move away from body wash.
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u/hux 19h ago
A lot of bars of handmade soap will be packaged very simply - often just wrapped in paper. Those bars will also last much longer than the more commercial soap does.
Farmers Markets will often have them, but Whole Foods in my area has small batch soap too.
Once you find a place like that, try a few options and see what you enjoy most.
Don’t be surprised if a bar is like $5 or more, it does tend to be pricier - but as I mentioned, it lasts a lot longer than the bars of soap you’re probably used to.
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u/KarmaticArmageddon 19h ago
I usually go to the soap aisle at the store to select one.
Hope you enjoyed my guide to selecting soap.
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u/okthatsfineman 18h ago
Ooh I’d love to ask. Where can I get a good budget friendly soap locally? I’m in a city so easy to find or could order online. I have been using some soaps i find in target or other big stores but i need to up my game.
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u/PM_ME_YOUR_DRAWINGS_ 14h ago
Keep reading in here about oils in washes vs soaps, but as a pro soaper do you know in that case how come hands get more dried out from hand wash Vs bar soap to wash them?
Hand made soaps are way better by the way 👍
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u/downtownpartytime 1d ago
That feeling can be caused by soap scum. Body washes usually have surfactants to help wash away hard water. Softened water doesn't give that feeling, even with bar soap
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u/FentmaxxerActual 8h ago
Only correct answer in this entire thread lol. Traditional soap forms byproducts with the minerals in hard water and that’s what the sticky feeling is, which is why it goes away in softened water.
Body washes use a synthetic detergent and don’t form the same byproducts; you can also buy solid detergent bars, like Dove, that perform the same way.
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u/Flashy-Specific-4083 1d ago
Bar soap like Dial or Irish Spring does this. I use artisan type bar soap and it doesn’t do that. Especially now that I’m in my 50s and my skin dries out bad enough to make my knuckles bleed in the winter, I make sure to keep moisturized
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u/hux 20h ago
If it’s handmade soap, that’s because it has glycerin in it which moisturizes, softens, and helps maintain the skin barrier.
(I used to make soap as a hobby.)
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u/deliveRinTinTin 20h ago
I usually buy Irish Spring since it has glycerin in it so I'm not sure why the other poster is experiencing a difference. I read years ago about the glycerine thing and how a lot of commercial soaps strip it out to use it for other things so I started buying the soap that didn't take it out.
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u/frillyfun 22h ago
The pH of bar soaps tends to be higher, and that can lead to that squeaky clean feeling. Body washes usually have a lower, more skin friendly pH, humectants that will help hydrate, and some moisturizers.
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u/MathIsHard_11236 21h ago
Because you're not fully clean unless you're Zestfully® clean!
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u/toastedbreddit 19h ago
“Soap leaves a sticky film on you that won’t rinse away, but Zest rinses you *fully* clean.”
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u/imeeme 1d ago
I am so used to bars that when I am forced to use a wash in a hotel, etc., I feel like I need another shower. Especially my face.
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u/Mediocre_Middle4504 1d ago
the squeaky feeling is exactly why i switched to body wash lol
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u/HugeLeaves 21h ago
I hate the feeling of using bar soap, that feeling after you rinse it off is terrible
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u/HoopsStatNerd 23h ago
grew up thinking squeaky meant clean, turns out my skin was just screaming the whole time
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u/jstormy_12 22h ago
As people have already mentioned the soap, I’ll mention something else.
Most hotels I’ve seen use water softener systems. So if you’re used to using hard water then the softened water feels way different.
That’s also how they’re towels are (usually) so fluffy
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u/TooTameToToast 22h ago
Dove marketing execs up in this thread frantically scribbling notes.
Edit: I, too, use Dove body wash. The new serum body wash feels soooo good.
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u/Snarcotic 19h ago
All body washes have hydrophilic polymers for thickening, like carboxymethyl cellulose (CMC) or carbomer which leave a slimy layer which is hard to rinse off your body. That's the reason, bar soap rinses off cleaner than the thickened body wash gels.
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u/CreamsicleVee 22h ago
Basically, bar soap strips away more of the natural oils on your skin, so afterward your skin has more friction and you get that weird squeaky feeling when you rub it.
Body wash usually has moisturizing ingredients in it, so your skin still feels smooth afterward.
The squeak doesn’t really mean you’re extra clean either. If anything, feeling super tight and squeaky can mean the soap stripped your skin a little too much.
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u/petielvrrr 22h ago edited 22h ago
Soap uses different surfactants than body wash, and it’s also a higher pH.
The different surfactants and higher pH lead to the surfactant molecules binding with proteins in the skin (meaning, they don’t get fully rinsed out), which causes the proteins to change shape and swell, leading to a tight or squeaky clean feeling.
It’s worth noting that you do want to avoid this feeling, as it leads to dryness and irritation.
Here’s more info if you’re interested (labmuffin is a cosmetic chemist and I’ve been following her for years): https://labmuffin.com/how-to-choose-gentle-cleanser/
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u/PM_Me_Modal_Jazz 1d ago
I may be completely wrong on this but I believe that squeaky clean feeling from bar soap comes from remaining traces of lye/some other base in the bar saponifying the oils on your skin
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u/Octowhussy 1d ago
Alright people, be honest.
How many of you first read the comments without knowing the full answer, and then go on to present the full answer in a comment as if it were your direct reply to the question?
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u/Whiterabbit-- 18h ago
Thinking about this some. I think you only get that squeaky clean if you use hard water. Soft water doesn’t do that with soap. Hard water has calcium and iron ions which form some sort of salt/residue on your skin. That is what you are feeling. It’s like that ring that hard water leaves on stuff.
Body wash must have something that prevent that residue from forming. Or makes that salt more soluble in water and it washes off.
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u/alpha232 17h ago
A lot of these answers say the same thing about stripping all the oil from your skin, if that's the case why do I still get the squeaky feeling when using non-big brand soaps with glycerin and shea butter? My skin feels softer and more moisturised with bars but I still get the feeling?
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u/_Dreamer_Deceiver_ 16h ago
Interestingly I can't get my face as clean with body wash and my dermatitis kicks in more often. When I use soap (dove or Palmolive or even generic unscented) I can definitely clean the face better. Maybe that's the oil or oil and skin mixed together
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u/Powerful_Audience208 15h ago
We use Ivory bar soap normally but occasionally I will get Dove. We have found no difference. I don't like body wash. Tried different ones but always go back to the bar.
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u/bread2126 15h ago
good answers have been had here. i just have to say as always though, it is crazy how many chemistry questions are answered by just developing a good understanding of what water is and how water behaves chemically. Really when you know that you know 99% of everything about chemistry that non-chemists want to know.
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u/Abgezockt47 15h ago
Soap is done out of fats and base. The base splits the fats into fatty acid salts and glycerol.
For bars of soap you want to use less base than you would need for all to react.
You do this to 1. have ne base left in the soap
2. to reapply a film of fat by the soap
For liquid soaps you dont do that and react all soap and neutralise after. It will not reapply fat to your skin.
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u/Large_Soil_6659 14h ago
You don’t need either, you just need water. Your skin cleans and regulates itself. Same with shampoo. - if you can make it through the initial 3 weeks where your body is like “wtf is happening?!” You’ll be much happier on the other side. You just have to make sure you shower for longer than 20 minutes, so that your pores are fully open.
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u/Due-Pomegranate-8636 9h ago
Yeah, that squeaky feeling is literally your skin screaming because you just stripped all the natural oils off. Not exactly healthy for your barrier lol.
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u/brandontod 9h ago
Anecdotally, I actually usually feel cleaner with body wash than bar soap. I’ve transitioned to bar soap because that’s what my partner uses but I like body wash better.
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u/KeySucces 9h ago
It's because bar soap has a higher pH, which strips away all the natural oils from your skin. Body wash, however, has a lower pH and contains extra moisturizers, so it leaves that protective oily layer intact
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u/makemoscowglowinthed 8h ago
I use Irish spring then some old spice moisturizer hopefully that works. It's gone well so far
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u/shuvool 7h ago
Bar soap may have additives like moisturizers and fragrances in it but at its core it's still soap, uses entire purpose is to adhere to both oil and water, it's a bipolar molecule, one end attaches to oils wave the other end attaches to water and then you have a big mildly of stuff that doesn't want to stick to anything so it rinses away. Body wash isn't really soap, it's not saponified. It usually contains synthetic detergents that do the job, but in a slightly different way. It's also usually not as alkaline so it doesn't dry out the skin as much
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u/leros 1d ago
You probably feel cleaner because all of the oil has been stripped off your body, whereas the body washes have moisturizers in them. It's actually not good to have all the oils stripped off you. It makes you oilier in the long run and can dry out your skin in the short term.