Why do elderly people's homes have a distinct ‘old-people’ smell?

As skin ages, it does tend to emit a different scent and possibly more aldehyde C9 and aldehyde C10 (aka: 2-nonenal and undecylenic acid). And if I were to describe these, I’d say: waxy, unctuous, ten day old orange (C10) or oily, over-ripe cucumber/ ten day old watermelon (C9). The relationship we have with our olfactory receptors is nothing if not mysterious - both those aldehydes are key components of…Chanel No 5 the world’s best selling perfume for almost 100 years! Which many grandmother’s chose to wear and is still being worn by their grand-daughters.

Someone mentioned elderly people smelling of urine, which is possible, given that all our pipes and whistles get a bit rusty as life enters the marathon stage. But…apparently sniffing a baby has universal appeal- but pretty much all the babies I have sniffed (and we’re definitely talking a number in the hundreds), with very few exceptions, were all attached to a nappy, at the time of sniffing. So I think the eau d’urine suggestion might also be flawed. It is possible that we humans are all fine with a bit of elder-smell, but in the right context.

I hate to be the one to bring it up, but as we’re heading this way - skatole is a scent compound found in many classic and modern perfumes and also, naturally found in human skin, It is synthetically made now, for perfume use, but, until a few decades ago, little furry mammals called hyrax, were chased down because they excreted particularly concentrated skatole. Castoreum is no better - those with a bit of Latin, probably know where this one is going - very few of the classic perfumes were free of a drop of it - found in beaver ‘castor sacs’ (actually produced by male and female beavers).

So, it seems we humans are fine with the scent of various human glands, but as we learn in perfume, context and percentage is everything.

Just for the record, I currently know two ladies who are over 80 - I sniffed one about a month ago, and she smells of warm russet apples (curiously, not Granny Smith) and olive oil; the other was just a stripling of 82, and I got benzoin, methyl ionone beta (Elnett hairspray is my guess there) with a subtle undertone of peppermint. No old ladies were hurt in this exercise and permission to sniff them was given.