I've gotten enough messages asking me to dupe the persimmon soap for 2-nonenal, the "old people smell," that I figured it was time to talk about it instead of replying to DMs one at a time.
You know how I operate by now. Someone asks me for something, I don't just start pouring. I dig into the science first. So I went down the rabbit hole. What I found is an interesting piece of chemistry attached to a bunch of marketing nonsense.
Let's get into both.
What is actually happening to your skin.
The smell people are calling "old people smell" has a real name: 2-nonenal. It's not a myth, it's not poor hygiene, and it's not something a person is doing wrong. It's chemistry.
Here's the short version. Your skin is coated in a thin layer of natural oils, produced by sebaceous glands. As we age, past about 40, the makeup of those oils shifts. A specific fatty acid starts showing up more, and as it sits on your skin and gets exposed to oxygen, it breaks down into a compound called 2-nonenal.
That compound has a distinct greasy, grassy, slightly musty smell, and it's significantly more difficult to wash off with plain soap and water, because it's oil soluble. It hides in the oily film on your skin rather than dissolving into water the way sweat does.
A few things make this worse. Your skin's ability to defend itself against that oxidation process (its natural antioxidant activity) also declines with age, so the reaction that creates 2-nonenal speeds up right as your skin's ability to slow it down goes down. Not exactly fair, but very human.
It's also not evenly distributed. Some parts of your body naturally produce more of the oil that feeds this reaction, because that's simply where your sebaceous glands are densest: your scalp, upper back, chest, and the area behind your ears. If you've ever wondered why a quick sniff test behind the ear is a real thing people do, now you know why.
Why we are not making a persimmon soap.
Here's where the marketing machine kicked in. Somebody figured out that persimmon tannin, in its raw form, has the ability to bind to and neutralize compounds like this. That part is real. Persimmon tannin (called kakishibu in Japan) has been used traditionally for centuries as an astringent and a dye fixative, and there is actual chemistry behind why it can grab onto certain molecules.
The problem is what happens to that tannin once it becomes a bar of soap.
Cold process soap making, which is how the vast majority of these bars are made, involves mixing oils with lye. That's an intensely alkaline environment, and it also generates heat as the reaction happens. Tannins are notoriously unstable in those conditions. Research on tannin chemistry shows that in an alkaline environment, tannins can lose the majority of their binding capacity within minutes, and heat speeds the degradation up even further. Cold process soap batter sits well within that danger zone during the actual saponification, and the finished bar still cures out mildly alkaline.
The one soap I did find that claims a 97% rate of 2-nonenal removal is a melt & pour soap. In the same listing as their persimmon soap, they offer a citrus scented soap that is also supposed to reduce 2-nonenal. It has nothing to do with persimmon. I'll explain more later. Bottom line, there are some other ingredients in the bars they produce that do make it a nice bar of soap but persimmon tannins aren't pulling through melted base poured at 140 degrees and time on the shelf before it reaches people.
Translation: by the time that pretty little bar makes it to your bathroom, the thing that was supposed to be doing the work has already broken down. You're left with a regular bar of soap wearing a persimmon costume.
Setting the chemistry aside, there's a second issue. Soap is a rinse off product. You lather, you rinse, you're done in under a minute. Even a tannin at full strength needs time to bind to anything. A few seconds of lather isn't it.
Most of what's on the market right now, even the more "clinical" sounding ones, are leaning on marketing language that outpaces what the finished product can do. Doesn't mean people are necessarily lying to you on purpose. Just means they either didn't stop to ask what soap making does to the ingredient before they jumped on the bandwagon, or it's one of the big corporations who know that following the instructions on any of those soaps to use it DAILY is more efficacious than the soap itself.
So no persimmon soap from us. Not because we're precious about it, but because it doesn't work in the way it's being marketed to.
What actually works.
Here's the good news. You don't need an exotic imported ingredient to deal with this. You need two things working together, and neither one of them is a fancy ingredient.
The first is mechanical lift. This is the part everyone skips, and it's the part that actually does the heavy lifting, pun intended. 2-nonenal sits inside an oily film on your skin, and that film needs to be physically agitated and lifted off, not just rinsed at. A soap without any friction behind it, no matter how nice the ingredients are, is just going to slide over that film and rinse away without ever disturbing it. This is why an exfoliant, a soap sock, a scrubbing belt, or good old fashioned fingernail massage on the scalp isn't optional here. Without it, even a great soap can't touch the waxy layer 2-nonenal is hiding in.
As we know, aging skin is more delicate. It thins over time, it holds onto moisture less, and it just can't take the same level of scrubbing that younger, more elastic skin can. So exfoliation matters, but the right amount and intensity is going to look different from person to person.
The second is the quality of the soap itself. A high lather dollar store bar and a well formulated, properly superfatted bar are not doing the same job on your skin, even with identical scrubbing behind them.
The third is consistency, because as we'll get into below, 2-nonenal doesn't stay gone.
So: gentle lift, matched to your skin's tolerance level, a soap formulated to support that, repeated often. Done.
Option one: our shampoo bars, used on scalp and body.
Our Moroccan Star shampoo bars are formulated for hair but fabulously conditioning for body as well. Here, use them on your scalp AND your body.
Your scalp is one of the biggest culprits in this equation, one of the most sebaceous gland dense areas on your entire body, which means it's also one of the biggest sources of 2-nonenal. Washing your body and ignoring your scalp is leaving a huge piece of the puzzle on the table.
The mechanical part matters here just as much as the soap itself. 2-nonenal sits in an oily film on your skin, and that film needs to be physically lifted, not just rinsed at.
This is especially true on the scalp. Don't just let shampoo run through your hair. Actually massage it into your scalp with your fingertips and nails, with real pressure, in circular motions. That mechanical agitation is doing a huge amount of the actual work.
If brittle nails, arthritis, or general finger strength make that kind of pressure hard to sustain, there are silicone scalp brushes for the shower that can help. Just like with the exfoliating bars we discuss below, pick one suited to what your scalp can actually handle.
On the body, load one up in a soap sock and you've got yourself a tool. We carry these in a few different textures depending on how much scrub you want: soft terry cloth, micro net or ramie sock for something a little more textured. We also recommend using a back scrubbing belt or cloth for the spots you can't reach easily on your own. We offer these tools, but they're also available other places. It really doesn't matter where you get them, being consistent is the key.
Our shampoo bars are our top recommendation for 2-nonenal elimination (in conjunction with agitation) because they are superfatted at 20%. That means that 20% of the oils in the bar are free and unabsorbed after the saponification process. Because 2-nonenal is lipophilic (oil loving) the free oils dissolve the 2-nonenal into themselves after agitation, the soap's surfactant molecules then grab onto that oil-plus-2-nonenal mixture, emulsify it and carry it away down the drain. Additionally high superfat means these bars clean without stripping, which means you can use them more often, on your hair and your skin, without drying yourself out.
As with any superfatted soap, the quality of the base ingredients is paramount because your skin absorbs that. We use organic food-grade vegetable oils & butters in all of our recipes.
Option two: our regular formula bars, with a built in exfoliant.
If a full soap sock routine isn't your thing, our regular formula bars (lower coconut ratio, still superfatted at 6%) come with exfoliants baked right in, and we offer a range depending on how much scrub your skin can actually handle.
A quick note here: we carry bars with botanical exfoliants, like ground lavender or chamomile buds, and plenty of you love them. We just wouldn't reach for those here, since those edges can be a little sharp, so we'd point you toward our rounder, smoother exfoliants instead.
For our exfoliating lineup, here's what we're working with, low intensity to high:
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Blue Corn y Comunidad, made with blue corn meal, is our mid range option. It gives you real texture without a single sharp edge, because corn meal grinds down round instead of jagged.
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Vanilla Bean Cappuchine, made with coffee grounds, steps it up. Definitely scrubbier, but still smooth, not pokey.
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Hard Workin' Hands is our heaviest hitter, with multiple exfoliating agents working together: coffee grounds, ground pumice, and activated charcoal. It was built for actual working hands, but plenty of clients have found their own uses for it, whether that's a daily heel scrub in the shower or a once a week deep exfoliation session. Choose this one if you enjoy a heavier exfoliation, but please test it carefully before applying regularly to full body.
Option three: Goatmeal & Honey, for the gentlest approach.
If your skin is on the more delicate or reactive side, or you just want the softest possible option, this is the one I'd point you to. It is formulated for delicate facial skin, but many people use it for body too, particularly for acne, eczema, psoriasis, or overall reactivity. It's colloidal oatmeal, goat's milk, alkanet root, and raw honey, superfatted at 6%. Because 2-nonenal and more fragile skin both come with age, this is our best recommendation for people over 75.
Colloidal oatmeal isn't just a soft texture. It's actually recognized by the FDA as a skin protectant, and it's been studied for decades for its ability to calm irritation and support a compromised skin barrier. The exfoliation it provides is about as gentle as mechanical exfoliation gets, fine enough to physically lift buildup without any risk of the micro tears you can get from a rougher scrub. Pair that with goat's milk, which brings moisturizing fats to the party, and raw honey, which adds a lovely, skin loving sweetness and softness to the bar, and you've got something that can be used daily, even on skin that can't tolerate much else.
For anyone dealing with skin that's also thinner or more easily irritated, this bar lets you keep up the necessary consistency without beating your skin up in the process.
It's not just about which soap, it's about the whole picture
A couple of other things are working against people here, and we have some solutions.
First, reach. The zones that produce the most sebaceous oil, your upper back and the nape of your neck, are also some of the hardest places to actually scrub yourself. This gets even more true as shoulders and hips stiffen with age. We recommend a back scrubbing belt or mesh cloth for this. Lather it up ahead of time, sling it over your shoulder, and you can get real contact and friction on the spots that need it most.
Second, how we actually bathe as we get older. Elder care guidance commonly suggests full baths only two or three times a week. Safety, energy expenditure, comfort, and the fact that skin can dry out with too much washing all play a role.
Here's the thing: 2-nonenal isn't a one time occurrence. It's being continuously produced as your skin's natural oils oxidize, day after day. A wipe down might knock back what's sitting on the surface in that moment, but it isn't giving you the lather, contact time, and mechanical lift that actually fights the buildup, and tomorrow your skin is already making more. A quick bird bath just isn't going to keep pace with a process that never stops running.
The dryness worry is real, and here's the fix
I know the instinct is to think "if the answer is washing more, how do I keep my skin from drying out?" And you're right to think that. Aging skin gets thinner, loses elasticity, and holds onto moisture less than it used to.
2-nonenal is formed when the fatty acids in your skin's surface lipid layer oxidize, and that oxidation happens more easily as your skin's natural antioxidant defenses decline with age. So the same aging lipid layer that's producing less protection and more dryness is also the layer breaking down into 2-nonenal. It's one system, doing two things you don't want.
This is where Kumo Kiss comes in. When you wash, you temporarily increase what's called transepidermal water loss, or TEWL, which is exactly what it sounds like: water escaping through your skin faster than it should. Applied right after you towel off, while your skin is still slightly damp, Kumo Kiss gets to work counteracting that spike, helping your skin hang onto its own moisture instead of losing it to the air. Kumo Kiss supports the same lipid barrier system that's central to this issue, and keeping that system healthy is vital for skin resilience as you wash more often. Pairing a gentle, more frequent wash with an immediate Kumo Kiss application means you get the necessary consistency without the dryness that would otherwise come with it. Wash more, moisturize right after, every time.
Know your hot spots
Not all skin is created equal here, some areas of your body simply produce more of the oil that feeds this whole process, because that's where your sebaceous glands are naturally the most concentrated:
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Your forehead
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Your nose and chin
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Your scalp
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Behind your ears
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Your chest
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Your upper back
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The genital area
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Your ear canal
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Around your nipples
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Your upper outer arms
You'll notice armpits didn't make the list. That's not an oversight. Armpits are dominated by a different kind of gland entirely, apocrine glands, which are behind regular sweat-and-bacteria body odor rather than this specific oxidation process. Different gland, different smell. But definitely still wash those. Lol.
The TLDR takeaway
There is no miracle bar that does this in one wash, no matter what the label says. What actually moves the needle is gentle, non-stripping cleansing, paired with the appropriate level of exfoliation for you, consistently, ideally daily. Follow it with moisture support so your skin doesn't pay the price for that consistency, and you're golden.
That's not as flashy as the hot persimmon trend, but it's what the science shows. A simple routine with quality products, performed regularly. Just like my grandma taught me. Of course.
The care routine I've laid out here can be done with any high quality soap. I reference ours because I am 100% sure about what is in each bar and what makes each one effective.
The funny thing is, I could grab some persimmon extract and make a “persimmon” soap that performs as well as what’s on the market but none of the soaps are helping BECAUSE of the persimmon, which is DOA by the time it gets to you. Judging from what I saw yesterday, I could also mark up our prices by as much as 4x and be competitive. Crazy what marketing can do.
Much love to everyone who reached out about this. I hope this answers all the burning questions you've had.
If you still have concerns or want a personalized recommendation, reach out. Email me at sunshinealchemistsandsoapco@gmail.com and we'll figure it out together.
Big hugs!
Your friendly neighborhood alchemist, Maaike