This is the objection that sinks the whole category, and almost nobody selling bars answers it out loud. Ask the internet whether bar soap is sanitary and you get soap makers going quiet and everyone else going vague.
There are two different questions inside it and they get mixed up constantly. Can organisms end up on a bar of soap? Yes, obviously, they end up on everything you touch. Do they come back off onto the next person? That's the one that matters, and unlike most things in this industry, it has been tested properly.
Soap does not kill anything. It lifts things off a surface and water carries them away. Hold on to that sentence, because every answer below is a consequence of it.
Does a bar of soap hold germs?
Bars can pick up organisms from hands, and studies find them there. What they do not do is transfer them onto you in any meaningful amount, because the lather and the rinse carry them off the bar and down the drain. The real problem with a bar isn't contamination. It's a bar left sitting in water.
Has anyone actually tested that?
Yes, and in about the most unpleasant way you could design. In a study published in Epidemiology & Infection in 1988, researchers deliberately smeared bars of soap with E. coli and Pseudomonas aeruginosa — at levels around seventy times higher than anyone has found on a bar in ordinary use — and then had sixteen people wash their hands with them, normally, the way you would at a sink.
Afterwards, none of the sixteen had detectable levels of either organism on their hands. The paper is Heinze and Yackovich, 1988, and it is still the study everything else in this argument refers back to.
I want to be precise about what that does and doesn't say. It says the object is not the risk people assume. It says nothing about my soap in particular, and I'm not going to dress it up as though it did.
Does soap kill germs, or just take them off?
Takes them off, and that's why the result above comes out the way it does. A soap molecule has one end that gets on with water and one end that gets on with oil, so lather surrounds the greasy film on your skin, lifts it, and rinsing takes the whole lot away — along with whatever was sitting in it.
That's a mechanical process, not a chemical attack. My bars are not antibacterial, they are not disinfectants, and I don't sell them as either. Removal is the thing that has always done the work at a household sink.
Can two people share a bar of soap?
In a household, yes, and most of the world always has. The lather-and-rinse mechanism doesn't care whose hands were on the bar before yours, and the transfer study was run on bars far dirtier than a family bar ever gets. The sensible exception is broken skin: if somebody has an open cut, give them their own bar until it closes.
That's a general-principle caveat, by the way, not something anyone measured. The other habit worth having in a shared bathroom is lathering into your hands or a cloth and then putting the bar down, rather than running the bar over yourself. It's better for the bar too.
Is liquid soap more hygienic than a bar?
Not automatically, and there's a study on that side too. Researchers looking at open, bulk-refillable dispensers — the kind topped up from a jug in public restrooms — found roughly one in four of them contaminated, and when they measured hands in an elementary school, washing with soap from a contaminated refillable dispenser increased Gram-negative bacteria on hands about 26-fold. Sealed refill cartridges reduced them. That's Zapka and colleagues, 2011.
Two caveats before anybody uses that to win an argument: it's about open bulk dispensers refilled from a container, not the sealed bottle you buy at a store, and not your bathroom. And it points at the same underlying thing the bar problem does — soap sitting in standing water for a long time, in a container nobody dries.
So why does the bar in a public restroom feel like that?
Because it usually is like that. A bar that never gets a chance to dry goes soft and slick on the surface and holds a layer of water, and a bar in a busy restroom never gets that chance. What you're recoiling from is texture, and the texture is a drainage failure.
The same bar in your bathroom on something that drains is a hard, dry object by the next morning. It's the same soap. It's a different situation.
What actually matters more than any of this?
Where the bar sits between washes, which is not really a hygiene question at all — it's the same answer as making the bar last, and I've written that out in how to make a bar last twice as long. Air underneath, water falling away, dry by morning.
If you're only going to buy one thing after reading this, buy the four-dollar draining dish rather than another bar of soap. It fixes the texture, the mush, the slime and the disappearing bar, all at once, and it's the cheapest thing in this entire shop that I don't sell.
Cosmetic products. Not intended to diagnose, treat, cure or prevent any disease.