What’s actually in the scent of a flower?
It’s probably not a question most people ask, but if you’re interested in the answer I’m presenting here a discussion of the components of the scent of hyacinth flowers. |
| Hyacinths in flower in the Pell Wall garden |
Most of these individual chemicals are available to the perfumer attempting to recreate the scent but as you can see the proportions vary according to the collection technique used. All the methods essentially involve collecting the scented air from above the flower - what is known in the trade as the headspace - and then working out what is in it, but there are a variety of means of doing that and they don’t all yield the same results. These results all came from blue hyacinth by the way.
Benzaldehyde 1.2 - 2.3
Cymene 0.2
Limonene 0.2 - 1.2
Benzyl alcohol 1.5 - 2.5
phenylacetaldehyde 1 - 1.1
trans-Ocimene 1 - 7.2
Phenyl ethyl alcohol 22.2 - 25.5
Benzyl acetate 13.7 - 20.1
Aldehyde C-10 0.5 - 0.6
Phenylpropyl alcohol 0.7 - 1.4
Phenyl ethyl acetate 2.4 - 7.7
Cinnamic aldehyde 2.9 - 4.6
Cinnamic alcohol 9 - 16
Methyl 2-methoxybenzoate 0.7 - 0.8
Eugenol 0.6 - 0.8
1,2,4-Trimethoxy benzene 7.2 - 11.6
Methyl eugenol 0.6 - 0.9
Cinnamyl acetate 0.2 - 0.5
alpha-Farnesene 5.1 - 6.3
Benzyl benzoate 6.3 - 9.3
Phenylethyl benzoate 1.1
I researched this when I was setting out to make my own hyacinth based fragrance - Persian Prince for my Spring Flowers Collection. You might reasonably wonder why I would go to so much trouble - surely you can just get hold of the essence of the natural flower and use that? Well with some flowers that’s certainly possible, though often the resulting essence does not smell much like putting your nose to the flower. In this case though according to White Lotus there is no real Hyacinth being offered anywhere today and I’m inclined to agree with them.
So instead it’s just a question of mixing all the elements on the list and hey-presto you have a hyacinth perfume?
Well not quite - for one thing the flower does not have to obey the safety rules set out by IFRA and summarised in this post. If you copy the flower scent exactly you end up with a perfume that might cause skin irritation when you spray it on yourself. Plus some of the chemicals are difficult to get hold of or not fully stable and of course, unlike the flower, your perfume isn’t going to be continually made on your skin and released into the air in a constant stream.
So some adjustments are needed to make it last on the skin, project out from it and still smell like the flower it is supposed to. Having the list certainly makes re-creating the scent a great deal easier though.
So now you know - anyone care to guess which is the single chemical from that list that most accurately represents the scent of hyacinth to the human nose?
A lucky guess: trans-Ocimene 1??
ReplyDeleteThanks for the guess Ankica, but no: trans-Ocimene is normally described as having a herbal smell rather than floral.
DeleteIt is present in the oils and flower scents of quite a large range of plants, but isn’t the most characteristic of the hyacinth.
So the competition remains open . . .
Hmm... well, I have several natural isolates at home from your list... but not sure if they really smell like Hyacinth...
ReplyDeletePhenyl ethyl alcohol?
You might just have the one I’m looking for actually - it is available as a natural isolate - but Phenyl ethyl alcohol isn’t the one: most people would describe that as more rosy in character. It forms part of the scent of quite a lot of flowers (including roses) and is a lovely material, very widely used in perfumery as I expect you know.
ReplyDeleteGetting warmer now though!
PEA is really rosy! That's why I didn't want to say it at first. :)
ReplyDeletePhenyl ethyl acetate is also goes rosy right? :)
Yes it is - also a component in quite a lot of flower scents - and not the characteristic hyacinth I’m looking for.
ReplyDeleteThe amazing thing is that 25% of the scent can be PEA and yet you’d never guess from smelling the flower. One of the wonders of fragrance is the way minor components can have a huge influence on the way we perceive an odour.
A complete guess - is it cymene
ReplyDeleteNot cymene no: p-cymene is also present in the scent of quite a lot of flowers and is one of the elements that isn’t stable in air. It has a strong citrusy, spicy scent which forms an important part of the freshness of spring flowers but isn’t the one I’m looking for!
ReplyDeleteBenzyl acetate??
ReplyDeleteA good thought as benzyl acetate has a lovely floral scent that is a key component of a number of flowers, particularly jasmine. Still not the essential character of hyacinth though . . .
ReplyDeleteIs it perhaps Phenylethyl benzoate, seeing as you suggested Ankica was close with the other phenyl one, not that I know why that might be .... :)
ReplyDeleteExcellent logic, but Phenylethyl benzoate is a honeyed rose scent rather like a richer version of PEA.
ReplyDeleteWe must be getting closer now though, if only because we’re running out of options!
Come on Chris you might as well tell us rather than me keep guessing!
ReplyDeleteYes OK, fair enough. The answer is phenylacetaldehyde - at about 1% of the fragrance it is surprising, but if you smell the stuff it just shouts hyacinth at you.
ReplyDeleteOh and the reason I said Ankica was close earlier is that phenylacetaldehyde is normally sold diluted in phenyl ethyl alcohol and I thought perhaps it might be one of the natural isolates mentioned . . .
Anyway it’s jolly good stuff, but heavily restricted by IFRA so that only a little can be used - so even though the flower has about 1% of it in the fragrance, just 0.3% is permitted in a perfume: one of the challenges to the perfumer in replicating the scent.
I’ll happily send both of you a little bottle of Persian Prince as a reward for the enthusiastic guessing if you’d like: just drop me an email with the necessary details.
I would never guess because it has "aldehyde" in the name. :D
ReplyDeletePersian Prince? Sounds delicious! :D
Apart from phenyl acetaldehyde, I have phenyl acetaldehyde dimethyl acetal in my collection. The odor of phenyl acetaldehyde dimethyl acetal appears to have a large overlap with the one from phenyl acetaldehyde. Do you agree that it might be an option to use this chemical? It is restricted to even 3% in the final product according to IFRA. What is your opinion about this?
ReplyDeleteHello Domek and thanks for the interesting comment. phenyl acetaldehyde dimethyl acetal (usually shortened to PADMA) certainly has some characteristics in common with phenyl acetaldehyde but it’s a much greener more leafy scent. You could certainly use some as part of the scent of hyacinth but it isn’t a substitute because it lacks the characteristic hyacinth note. If you have any verdilyn though, that makes quite a good substitute and (like PADMA) isn’t restricted by IFRA at all.
ReplyDeleteI’m guessing that you got the 3% figure from the Good Scents Company page (http://www.thegoodscentscompany.com/data/rw1009971.html)? The thing to remember about those is that where they give a recommended amount, that’s the maximum they are suggesting should go into the fragrance concentrate - which is normally assumed to be no more than 20% of the final product. This is in contrast to IFRA restrictions which are expressed as a percentage of the final product. So 3% in the concentrate is the equivalent of just 0.6% in the product - however it isn’t an IFRA restriction. When there is an IFRA restriction The Good Scents Company page shows it like this one for phenyl acetaldehyde (http://www.thegoodscentscompany.com/data/rw1009931.html).
Hello Chris,
ReplyDeletethank you for the clarification about the information on the good scents company page and for the interesting proposal to use verdilyn as substitute. I'll need to find out what it smells like.