No bicarbonate or vinegar: the trick to finally banish ‘old person’ odour with this type of soap

Researchers are honing in on a single skin molecule - and a kinder way to deal with it.

Many people start to notice a grassy, slightly stale whiff on clothing or skin from midlife onwards. It isn’t a sign of bad hygiene. The culprit is often 2‑nonenal, a compound produced when skin lipids oxidise. As we age it tends to accumulate, and it can become stronger with rich diets, ongoing stress and certain medicines.

What actually shifts as you get older

As the years pass, the make-up of skin sebum changes. A higher proportion of unsaturated lipids can oxidise both on the skin’s surface and within fabric fibres. This oxidation creates 2‑nonenal, a small aldehyde with a “cardboard-meets-herbs” edge that readily sticks to collars, pillowcases and knitwear. Washing helps, but the odour may reappear quickly because the source is held in sebum and in textiles - not just sweat.

From around 40, hormonal shifts can contribute too, alongside everyday patterns. High-fat foods, poor sleep and long-term stress all encourage oxidation. Some medicines can also change sebum composition. None of this means you’ve done anything wrong - it simply calls for a more targeted routine.

"The musty note linked to ageing stems largely from 2‑nonenal. Target the molecule, not the person."

Persimmon soap and 2‑nonenal: a more targeted wash

Soaps featuring persimmon (kaki) extract are drawing interest because they neutralise aldehydes, including 2‑nonenal, rather than trying to cover them with heavy fragrance. Persimmon extract contains polyphenols and tannins that can bind to odour molecules, as well as antioxidants that may help curb new oxidation at the skin’s surface.

Why persimmon works

Polyphenols can attach to small aldehydes and make them less volatile. Meanwhile, gentle surfactants remove sebum without wrecking the skin barrier. A lot of products are low-fragrance or fragrance-free, which avoids conflicting scents and can reduce irritation risk.

How to use it

• Build a thick lather from the bar or gel using warm water.
• Focus on areas where odour tends to linger: neck, behind the ears, chest, back and underarms.
• Let the lather sit for 30–60 seconds to give it enough contact time.
• Rinse thoroughly and pat dry, then use a light, non-greasy moisturiser.
• Use it daily for two weeks, then adjust based on what you need.

"Contact time beats elbow grease. Let the lather sit, then rinse. No harsh scrubbing needed."

Stainless steel “soap” for quick neutralising

A stainless steel bar - traditionally used to remove garlic and fish smells in the kitchen - may also help with stubborn odours on hands and certain body areas. When wet skin is rubbed against the steel, odour molecules can transfer and bind at the metal interface. There’s no fragrance, no lingering film, and the bar can last for years.

Safe, simple steps

• Run the steel bar under the tap to wet it.
• Rub over wet hands or freshly cleaned skin for 30 seconds.
• Rinse and dry; use a mild wash alongside it if you need proper cleansing.
• Don’t use on broken skin, and avoid excessive rubbing on delicate areas.

Think of a steel bar as a fast “odour reset”, particularly for hands after cooking or handling gym kit. For body care, many people use it alongside a gentle cleanser, or combine it with persimmon soap on shower days.

Options at a glance

Option	What it does	Best for	How to use	Notes
Persimmon soap	Neutralises 2‑nonenal and cleanses	Daily shower routine	Lather, leave 30–60s, rinse	Choose low-fragrance, pH-balanced formulas
Stainless steel bar	Binds stubborn odours on contact	Hands or quick touch-ups	Rub on wet skin, then rinse	Not a cleanser; pair with soap
Standard deodorant	Masks scent and reduces bacteria	Underarms	Apply to dry skin	Doesn’t target 2‑nonenal directly

Sensitive skin, handled

If your skin is easily reactive, check the ingredients list carefully. Helpful additions include aloe vera, glycerin, panthenol or ceramides, which support the barrier while you deal with odour. Keep fragrance minimal. Avoid gritty scrubs and daily high-strength acids, as these can increase inflammation and, ironically, make smells hang around by disrupting the barrier.

The format matters too. A creamier bar or a syndet (synthetic detergent) with pH ~5.5 is kinder to the acid mantle, helping skin stay settled while persimmon extract gets on with the job.

Lifestyle levers that reduce the whiff

• Cut back on deep-fried foods and late-night drinking, as both drive lipid oxidation.
• Keep stress in check with small, repeatable habits: brisk walks, breath-work and a consistent bedtime.
• Drink enough water; dehydrated skin can concentrate sebum by-products.
• Choose breathable fabrics - cotton and bamboo usually outperform tight synthetics.
• Adjust laundry habits: enzyme detergents, a 60°C wash for towels and gym kit, and complete drying to prevent mustiness.
• Rotate outer layers and air them between wears; sunlight can help break down odours.
• If a medication lines up with a sudden change in body odour, speak to your GP before altering anything.

A realistic timeline

With proper contact time, many people detect a milder scent after the first wash. After about a week, fabrics often retain less of the stale trace. By weeks two to three, results are typically more consistent as skincare and laundry routines start working together. Aim for gentle consistency rather than an aggressive approach.

Pitfalls to avoid

• Trying to cover it with strong perfume can simply layer smells; neutralise first, then add fragrance only if you want to.
• Scrubbing too hard can damage the barrier and may worsen odour over time.
• Incomplete rinsing leaves residue that can trap aldehydes in fibres.

A simple weekly game plan

Daily: wash with persimmon soap, let the lather sit briefly, rinse well, apply a light moisturiser.
Midweek: use a steel bar as a touch-up for hands or around the collar line after cooking or commuting.
Weekly: hot-wash towels and gym kit with enzymes, then dry completely. Replace pillowcases midweek if you use rich night creams.

Extra tools if you want them

Some people find a gentle lactic acid body lotion once or twice weekly helps keep skin smoother and less odour-prone by reducing oxidised build-up. Keep it mild, and don’t use it on the same day as shaving. For fabrics, bicarbonate and vinegar can irritate skin or harm fibres, which is why this approach avoids them and focuses on targeted chemistry instead.

"Small, repeatable steps beat drastic fixes. Neutralise the molecule, clean the fabric, then keep the barrier happy."

Key term to know

2‑nonenal: an aldehyde created when certain skin lipids oxidise. It can smell grassy, stale or like old fabric. Persimmon extract binds and neutralises it, which is why these soaps can be surprisingly effective.