What We Forgot About Shaving

People have been scraping hair off their faces and heads for about five thousand years. Reasonably well, too. Egyptian priests shaved their entire bodies every other day. Roman men were clean-shaven as a matter of social standing. Nobody was walking around with a face full of razor burn and a shrug.

So here's a fair question. If we've been doing this successfully for five millennia, and modern shaving is supposedly the product of all that accumulated progress, why does so much of it end in redness, bumps and that tight, dried-out feeling?

I went looking for what changed. The answer turned out to be more interesting than I expected, and it isn't really about ingredients at all.

Did the Romans use soap to shave?

Mostly, no. And that corrected an assumption I'd started with.

I went in expecting the history to back a simple story: traditional shaving soap was better, industrialisation ruined it, case closed.

The history did something more useful. The Romans, who were fastidious about being clean-shaven, largely didn't wash with soap at all. The J. Paul Getty Museum's notes on the strigil put it plainly: soap existed in the ancient world, but it was used for laundry and medicine, and wasn't normally used for bathing until the late 200s AD. Before that, Greeks and Romans coated themselves in oil, worked in an abrasive like fine sand or ground pumice, and scraped the whole lot off with a curved bronze tool.

They knew about soap. Northern European peoples used it. The Romans just didn't rate it for skin.

Egypt tells the same story. Barbers carried oils, frankincense and myrrh among them, copper and bronze razors, and pumice stones for smoothing the skin afterwards. Herodotus recorded the priests and their every-other-day full-body shave. Roman men finished a shave by rubbing pumice over whatever stubble the blade had missed.

No lather. No brush. Oil, a blade, an abrasive, and someone taking their time.

Specialised shaving soaps and lathering brushes don't really turn up until the 1700s. In the long history of shaving, soap is the newcomer.

What makes beard hair easier to cut?

Water, and time for it to work.

Strip out the specific materials from every method that has ever worked and the same four things happen before the blade touches skin. Warmth. Water. Fat. Time.

Egyptians oiled. Romans oiled, scraped, rinsed and oiled again. Turkish and later Victorian barbers wrapped faces in hot towels and worked lather in with a brush for minutes at a stretch. Different centuries, different materials, identical logic.

And it turns out they were right, for reasons nobody could have explained until fairly recently.

A 2016 paper by Maurer and colleagues in the International Journal of Cosmetic Science looked at what actually makes beard hair difficult to cut. Dry beard hair is genuinely tough. The paper notes it's been compared to copper wire of the same diameter in terms of the force needed to sever it. No wonder a dull blade drags.

But wet it, and it changes. Hydration drops beard hair stiffness by somewhere between 30 and 65 per cent. The force needed to cut a hair falls by around a fifth after one minute of contact with water, and around 40 per cent after four minutes.

Four minutes. That's the whole trick. That's what the hot towel was doing, centuries before anyone could measure it.

Every traditional method built that waiting time in, not because they'd read the research, but because barbers who shave twenty faces a day with a cut-throat razor work out fairly quickly what makes the job easier.

Is shaving foam better than soap?

It's faster. That was always the point, and it's worth knowing what was traded for it.

In 1919 a former MIT professor called Frank Shields launched Barbasol. Its selling point was that you no longer needed a brush to work soap into a lather.

Barbasol's 1919 pitch wasn't a better shave. It was less preparation.

It worked. When pressurised aerosol arrived in 1949 with Rise, the market moved fast. Within about a decade, cans held roughly two thirds of the American market, and they cost more than the soaps and creams they replaced. People weren't buying performance. They were buying speed.

Here's the part that surprised me most. Canned foam isn't some alien chemistry. Look at the formulations and they're typically 70 to 90 per cent water, with something like 7 to 13 per cent fatty acid soaps and a few per cent propellant.

It's soap. Watered down and filled with gas.

So the honest charge against the can isn't "chemicals". It's that it's dilute, it's mostly air, and it's sold on the promise that you can spray it onto a barely-wet face and start shaving immediately. Which is exactly the four minutes the evidence says you shouldn't skip.

Why is glycerin removed from commercial soap?

Because it became worth more sold separately, and that happened for a genuinely odd reason.

When you make soap, saponification produces glycerin as a by-product. Glycerin is a humectant, meaning it draws moisture toward skin rather than away from it. For most of soap-making history it stayed in the bar because there was nowhere else for it to go.

Then nitroglycerin happened, and then dynamite, and suddenly glycerin was worth real money. A waste product became a commodity. Methods for pulling it out of soap lye matured through the 1880s and 90s, including work by Julius Lewkowitsch, a chemist at the soap manufacturers Joseph Watson and Sons in Leeds from 1887, who developed a way of extracting it without using arsenic.

Industrial soap-making has stripped glycerin out and sold it on ever since. It ends up in moisturiser. Which you then buy, to fix the dryness caused by the bar that had its glycerin removed.

Cold process soap, made slowly in small batches, keeps it. That's not a performance claim, it's just what happens when nobody takes it out.

Every historical shaving method put fat onto the skin. Egyptians oiled before the blade. Romans oiled, scraped and re-oiled. Traditional soap kept its glycerin by default.

Modern cleansing does the opposite. It's built to take fat off, then sell it back to you in a separate bottle.

What about pH? Isn't soap too alkaline?

You'll find this argument everywhere, and it deserves a straight answer rather than a defensive one.

Yes, mainstream dermatology generally prefers synthetic detergents over soap on pH grounds. Skin sits around 4.5 to 6. Soap is often quoted at 9 to 11. That's a real position held by serious people, and I'm not going to pretend otherwise.

Two caveats worth knowing, though.

The first is that most of that literature is testing mass-market industrial bars, the ones with the glycerin removed, and generalising from there to all soap. A 2018 paper in the journal Molecules found cold-saponified soap runs closer to pH 7 to 8, with meaningfully more glycerin retained. Same word, different bar.

The second is that the point is less settled than the internet suggests. A review in the Indian Journal of Dermatology notes the alkaline-soap-damages-skin position, then immediately notes that other researchers have found cleanser pH has little effect on skin damage.

And a note on the other side, because it cuts both ways. "Syndet" isn't a swear word or a synonym for SLS. Sodium cocoyl isethionate is a synthetic detergent and a mild one. We use it ourselves in a shampoo bar. The real problem with cheap cleansers isn't their pH, it's that they're built to strip and then don't put anything back.

Cleansing without conditioning. That's the actual complaint.

What should you actually do differently?

The uncomfortable conclusion of all this research is that the most effective thing you can do about your shave costs nothing.

Get your face properly wet, with hot water, for a few minutes before you start. Shave at the end of a shower rather than the beginning. Don't spray foam onto dry skin and go straight in.

That's the four minutes. It does more than any product decision you'll make, and I'd rather tell you that than not.

Where the product comes in is the fat. Whatever you use should be leaving something behind on your skin, not just lifting oil off it. That's what every method from bronze-age Egypt to a Victorian barber's chair had in common, and it's the thing the can dispensed with.

Ever notice that the shave itself was never really the problem? It's everything you skipped beforehand.

A note on our own soap

For the sake of being straight with you: we're currently testing whether our own bars work as a shaving medium. Some of them contain kaolin clay, which is the standard slip ingredient in proper shaving soaps, along with shea butter and castor oil. Others, like Sports Day, are a traditional Castile formulation with none of that.

What none of them have is the high stearic acid content that gives a dedicated shaving soap its staying power across multiple passes.

We'll publish what we find, including if the answer is "not as well as we hoped". Seemed only fair to say that now rather than after.

Frequently asked questions

Can you shave with ordinary soap?

Yes, though a dedicated shaving soap will hold its lather better across multiple passes. Shaving soaps are formulated with a high stearic acid content, roughly 25 to 50 per cent, plus clay for slip and often a dual lye for a lather that loads on the brush and stays put. A good cold process bath bar will lather and let a blade pass, but the lather tends to thin faster.

How long should you wet your beard before shaving?

Around four minutes with hot water. Research in the International Journal of Cosmetic Science (Maurer et al., 2016) found the force needed to cut beard hair drops by about 20 per cent after one minute of water contact and around 40 per cent after four. Hydration also reduces beard hair stiffness by 30 to 65 per cent. Shaving at the end of a shower rather than the start does most of this for you.

Did the Romans use soap?

Rarely for washing. Soap was known in the ancient world and used for laundry and medicine, but it wasn't normally used for bathing until the late 200s AD. Greeks and Romans applied oil to the skin with an abrasive such as fine sand or ground pumice, then scraped it off with a curved bronze tool called a strigil. Roman men often finished a shave by rubbing pumice over remaining stubble.

Is shaving foam just watered-down soap?

Largely, yes. Typical aerosol shaving foam formulations are around 70 to 90 per cent water, with roughly 7 to 13 per cent fatty acid soaps and a few per cent propellant. The chemistry isn't alien, it's dilute and aerated. The bigger issue is that canned foam is sold on being applied to a barely-wet face and shaved immediately, which skips the hydration time that does most of the work.

Is soap too alkaline for skin?

It's more contested than it's usually presented. Skin sits at roughly pH 4.5 to 6 and mass-market soap is often quoted at 9 to 11, which is the basis for the standard dermatology preference for synthetic detergents. But a 2018 paper in Molecules found cold-saponified soap runs closer to pH 7 to 8, with more retained glycerin, and a review in the Indian Journal of Dermatology notes that some researchers find cleanser pH has little effect on skin damage. The more useful question is whether a cleanser puts anything back, not just what its pH reads.

Sources

Maurer et al., "The male beard hair and facial skin: challenges for shaving", International Journal of Cosmetic Science, 2016. J. Paul Getty Museum collection notes on the Roman strigil. Herodotus on Egyptian priestly practice. Barbasol and Rise company and product histories. Molecules, 2018, on cold-saponification pH and glycerine retention. Indian Journal of Dermatology review on cleansers and skin pH. Julius Lewkowitsch biographical detail, Society of Chemical Industry records.

Written by James Allan. Last reviewed 18 September 2026.