The science of raw fermented papaya, enzymatic skin cell renewal, and why AYA Natural Skin uses the ripest, most bioavailable form of papaya.
Papaya: There's More To It Than Meets The Eye
Clearly, papaya is my favourite fruit, and not necessarily for all the reasons you might think. Yes, raw fermented papaya is our active ingredient and the basis of AYA Natural Skin. We are so grateful every day for this magical fruit. It's just like everything else; there is so much more to it than meets the eye. And here comes my all-time corny humour, while stripping may have been a favourite pastime in my youth, I mean running naked into the sea in the moonlight is a thing, right? But it is the stripping of skin that I am seriously opposed to - and most cosmetic skin stripping has one active ingredient behind it: papain, which comes from papaya.
Our Skin Has Its Own Rhythm. Why we should be listening.
There are so many reasons I am opposed to skin stripping, and, for me, the main reason is that skin has a natural rhythm, a 28-day cycle. Here is where I love it: that number isn't arbitrary. It mirrors the lunar cycle, which is probably why Ayurvedic healers were tracking cyclical skin renewal thousands of years before Western science caught up - first with a German anatomist describing epidermal cell turnover, and then in the 1960s with an American dermatologist studying skin cell kinetics, the science of how long a cell takes to be born, mature, migrate upward, and die.
This is where the 28-day figure got its clinical legitimacy — though I'll be honest, the lunar connection is contested. There's no robust clinical evidence directly linking skin cell turnover to moon cycles. It's essentially observational and anecdotal, rooted in traditional medicine and folk wisdom rather than controlled studies. For me personally, the connection to the lunar cycle makes so much sense, being a Pisces and knowing how my own peace of mind and a good night's sleep can shift with a moon cycle, 28 days is an average, not a rule.
Another aspect, before anyone dismisses the lunar connection entirely, a woman's ideal menstrual cycle is also 28 days, long linked to the moon across cultures from Ayurveda to Traditional Chinese Medicine. The word menstruation shares its root with the Latin for "month" and the Greek for "moon". I mean, how beautiful is that?
The cycle slows considerably as we age, stretching to 45 or even 60 days in mature skin, and is knocked about by stress, sleep, and nutrition. So when someone tells you to wait 28 days to see results, what they're really describing is the baseline of a healthy young adult. Your skin may be working to a completely different rhythm, and that's not a flaw. That's just your skin doing its own thing, on its own timeline.
The Skin Barrier: What It Is and Why It Deserves Protection
The dislike of stripping is that not only does it disrupt the natural cycle and flow, but it leaves our skin very unprotected and exposed. The layers of the skin are there for a purpose, and the top layer, the stratum corneum, is made up of flattened, hardened skin cells bound together by lipids, essentially a brick-and-mortar structure that acts as your body's first line of defence. I remember going to a wedding (going to be discreet here and not say whose) and the beautiful bride had just been to a renowned spa for a treatment that involved a lot of chemical stripping, peeling and supposed skin renewal. All fine and well till a few days after the wedding, while on a magnificent honeymoon at a sun-blessed beach, not only could she not spend a second in the sun, but her skin looked like it had been flagellated. Needless to say, there were very few beautiful honeymoon photos.
But this wasn't my first experience of stripping and peels. As a teenager, I had seriously unhappy skin; rather than allowing my skin to express what it needed to and find a way of natural comforting support, my mother and grandmother went charging me off to a beautician whose sole purpose, as far as I was concerned, was to cause me immense pain and discomfort. Besides the fact that I was not a wise teenager, going in the sun sans hat or sunscreen was par for the course. Yes, I have extensive skin sun damage that I have found my own solutions to, but I always wonder to myself what role the peeling and stripping had in all of this. If you want to go deeper on what a compromised skin barrier actually means for your microbiome, I wrote about it in detail in Your Skin's Secret Garden.
Same Fruit. Completely Different Intention.
The irony is not lost on me that the very ingredient the industry uses to strip the skin comes from the same fruit that sits at the heart of AYA. The difference is everything. Unripe, green papaya contains the highest concentration of papain - and that is precisely why it is the cosmetic industry's weapon of choice for peels and enzyme treatments. It is potent, aggressive, and effective at removing everything in its path, which is exactly the problem. What most people don't realise is that the vast majority of commercial papain products on the market are extracted using exactly this method, unripe fruit, high concentration, heat and chemical processing, which is precisely why so many people experience irritation and over-exfoliation without really knowing why.
At AYA, we use sun-ripened papaya because we believe, as with skin, that nature should be allowed to take its course. As the fruit ripens in the sun, the papain concentration naturally reduces, and the nutritional profile deepens - more Vitamin C, more beta-carotene, more antioxidants. The raw fermented papaya benefits only become fully available when the fruit has been allowed to complete its natural biochemical cycle. What you are left with is a form of papain that is gentler, more balanced, and far more intelligent in how it interacts. It works with your skin's natural rhythm rather than forcing it into submission. And then we ferment it - which breaks it down even further into molecules the skin can genuinely absorb, rather than simply react to. Same fruit. Completely different intention. And for those of us carrying years of sun damage like myself, having an ingredient that repairs without further aggravating is just an essential gift.
Why Sun-Ripening First Changes Everything
Most papaya is grown in Limpopo, where the fruit grows slowly under intense heat, deeply concentrating its bioactive compounds. Full sun-ripening allows the fruit to complete its natural biochemical cycle; sugars, antioxidants, beta-carotene, and vitamin C all reach peak levels before harvest. A sun-ripened papaya has significantly higher lycopene and beta-carotene content than an unripe or greenhouse fruit, and both are powerful skin antioxidants that make the raw fermented papaya benefits richer.
There is one more reason we love papaya, and it has nothing to do with enzymes. Papaya is considered one of the least-sprayed fruits in South Africa, regularly appearing on "clean" produce lists alongside avocados and pineapple, and this is not accidental. The fruit's thick, protective skin acts as a natural barrier, meaning pesticides applied to the outside simply don't reach the edible flesh beneath. In many parts of South Africa, papayas face relatively low pest pressure to begin with, so growers don't need to spray heavily. When intervention is needed, farmers tend to use targeted fruit fly baiting along the edges of orchards rather than blanket spraying the entire crop. There are also very few pesticides specifically registered for use on South African papaya, which forces a natural reliance on fewer chemical interventions during growth. Most post-harvest treatment occurs via a fungicide dip rather than repeated field spraying, so by the time a papaya reaches us, it has lived a remarkably uninterrupted life. I have to say I refuse to buy into organic labelling as a status symbol. For us, every ingredient must pass the 'would I put this on my newborn' test - that is the standard I adhere to
The natural fermentation process is also more effective when it starts with a nutrient-dense, fully ripened pulp; there is simply more to unlock. Which brings us to why the fermentation itself is where the real transformation happens.
What Fermentation Actually Does to the Fruit
Fermentation transforms the pulp entirely - breaking down cell walls, increasing bioavailability, generating postbiotics that support skin barrier repair, and tempering raw papain into something that supports enzymatic skin cell renewal gently enough for daily use and sensitive skin. The fermentation skincare benefits go far beyond preservation; it is a complete biochemical transformation that is how fermented papaya heals skin in a way no raw or chemically extracted ingredient can replicate. We have been doing this since 2012, and getting it right, stabilising the enzyme activity consistently across every batch, that was a process in itself. If you want the full science, I went deep on it in Holy Moly, It's Alive!.
Enzyme Exfoliation vs Acids - Why We Chose Enzymes
The beauty industry defaulted to acids, AHAs and BHAs. Essentially, they are cheap, standardised, and deliver a result fast enough to feel dramatic. Glycolic acid, salicylic acid, and lactic acid, when used at high concentrations, work the same way: they lower the skin's pH aggressively, dissolve the bonds between cells, and force the surface to shed. The problem is that they cannot discriminate. They do not know the difference between a dead corneocyte ready to leave and a healthy living cell that isn't. The result is the kind of skin barrier damage we talked about earlier - a cycle of stripping and recovering that, once you're in it, is very hard to get out of.
Papain works differently. It is a proteolytic enzyme, essentially molecular scissors, that digests only dead, hardened keratin. It stops at living tissue. It cannot breach what is healthy. Unlike acids, it is a natural anti-inflammatory for the skin, calming as it clears rather than aggravating as it exfoliates. For anyone with rosacea, eczema, sensitivity, or mature skin, enzyme exfoliation vs acids - it's really the only logical choice.
I wrote about this in more detail in Skincare SOS: The Hazards of Over-Exfoliation if you want to go further down that particular rabbit hole.
The Would-I-Eat-It Test
Every ingredient in AYA passes one test before it passes anything else: would I put this on my newborn? Not a patch test, not a dermatologist sign-off, not a safety data sheet, my newborn, and now my very tall teenagers. That single question has kept every petroleum derivative, every synthetic fragrance, every liquid polymer, and every ingredient I couldn't pronounce out of every formula we have ever made.
The food-grade standard follows from the same logic. If I wouldn't eat it, doesnt mean I have to enjoy it, it doesn't go in. Which sounds extreme until you consider that we start with a papaya, something you could have for breakfast this morning, and end with - and here comes the hyperbole - a petroleum-free, enzymatic, multi-purpose healing balm that your skin recognises as its own. Raw fermented papaya, beeswax sourced directly from beekeepers, cold-pressed oils, nothing that doesn't belong. These are skin barrier repair ingredients in the most literal sense: food for the body's largest organ, in a form it can actually absorb and use.
So here we are - back where we started, at the water's edge in the moonlight. Stripping, as it turns out, is best left to midnight swims for the younger generation, not our skin. Papaya taught me that. Years of working with this fruit have made me deeply respectful of what happens when you allow nature to complete its own process, the fruit ripening slowly in the Limpopo heat, the fermentation doing its quiet work over days, the skin cycling through its own unhurried rhythm. None of it rushed. None of it was forced. That is the philosophy behind every tin of AYA Balm, and it has never changed.