Ok so here is my second input into the Aroma Chemical Study. For those who didn’t see the first post – this isn’t something to take too seriously. My knowledge is extremely limited on this subject but it is a beginner’s input into the descriptive words that can be placed with some of the most common aroma chemicals, and their possible uses.
A little bit of education is all
I hope it helps at least one person out there…
Geraniol starts extremely subtle with a smell almost similar to sushi – ever so slightly salty, aquatic, maybe even a little bitter. But it is extremely light, almost ozonic and not repulsive – more underwhelming.
It’s green, leafy and gradually increases in strength on paper over time. A green rose note blossoms out and yet again, smells slightly ethereal and ozonic – almost as though you are smelling the dew drops on a green rose rather than the rose itself. The green note is geranium, and has the same feel as the way it smells of rose – transparent.
I noticed this chemical in great volume in The Different Company’s Osmanthus – it practically is Geraniol after half an hour or so…
It’s used as a blender and also a floraliser – which enhances certain aspects ie. the green freshness of a rose.
It’s pretty harmless on its own and whilst not the most pleasant or complicated aroma chemical, it can be used up to 30%.

Dimenthyl Octenone is a bright, almost bitter leafy citrus. It is extremely close to the smell of lemon tea only warmer. The tea leaves are bitter and when I initially smelt this chemical on its own – I mistook it for the scent of cannabis. It has that dank, dirty smell that some citrus’ have – like grapefruit smelling like urine…
Having mentioned grapefruit – this aroma chemical is often used in grapefruit effects and it has that bitter/acidity which most likely pops up in fragrances like Guerlain’s Aqua Allegoria Pamplelune.
The citrus is piercing and dense, used to anchor lighter citrus notes as well as create new citrus effects (grapefruit /blood orange and the like).
Having constantly described it as “dense” – it is still a citrus, and holds the typical fresh/fruity character.
Helional is quite unusual when explored properly – but on first sniff is easy to mistake for a standard, slightly grassy/ozonic aroma.
In time, Helional gains some more substance, and gathers a slightly salty almost seaweed like accord, that ever so slightly reminds me of fragrances like Mr.Hulot’s Holiday by CB I Hate Perfume and the beautiful Dans Tes Bras by Frederic Malle. It has that salty/skin like smell, the tiniest bit soiled and sweated. It is subtle, and easily mistook for underwhelming.
It actually has a sweetness to it that others often identify as hay, I don’t really pick that up myself, but it may give a further insight into my soiled skin kind of association.
It is used in marine accords, adding an almost faux ambergris type note without the muskiness.
Coumarin derives from tonka, and has a really beautiful scent.
I first recognize it as a tropical, almost coconut-y scent, something that I detect in higher doses in numerous fragrances – Humiecki & Graef’s Bosque, and even Manoumalia - Les Nez for some reason were the first fragrances to pop into my head when smelling this chemical for the first time. But coumarin pops up in nearly every fragrance, providing a beautiful, creamy and almost oriental powdery/muskiness.
After a short while on paper, the tropical aspect settles and up comes a delicate almond/marzipan note where coumarin remains from there on. It is a long discovered isolate used in some of the great classics from the early days – Fougere Royale and Jicky were some of the first fragrances to incorporate synthetics and coumarin.
Similarly to Helional, it is also described as having a hay like aroma, and is known for its use in fougeres due to its perfect pairing with lavender - providing a warm, herbaceous velvety effect.
Personally when I first smelt this I pictured a purple dusting of powder – hence the picture
I love this aroma chemical, it’s almost like it was designed to be universally loved.
Hopefully whoever reading this is still awake ![]()
I’m getting the more “plain” chemicals out the way to leave way for the avant-garde’s and synthetic musks (my love!).





