Olfactory Chemistry: Lactones- Peaches and Cream

“I’ll take cream in that” is a common phrase when talking about the way you like your coffee or tea. When a perfumer wants to add creaminess to a perfume they are composing they mostly turn to one class of compounds called lactones. The names of these compounds are derived from the Latin phrase for milk, lac lactis.

esterlactone

Lactones were discovered in the early 1900’s as chemists found a way to cyclize esters. A beneficial side effect of this cyclization was it took esters that couldn’t be used for perfumery because they were so short lasting because of their volatility. The cyclic form could last on skin for hours, even days in some cases. The very simple case is shown above as methyl propionate is the ester on the left and when it is cyclized it is called gamma-Butyrolactone. Lactones are also found naturally, most prominently in tuberose. There are so many lactones in tuberose new ones have been discovered as recently as 2004.

peach coconut lactone

Almost from the moment they were discovered the lactones became key components of perfumes. One of the most influential, in perfumery, is one called Peach Lactone. Chemically you can see it is an analog of the gamma-lactone with a long carbon chain attached to it and is called gamma-Undecalactone. For no reason I have ever been able to understand it is also called Aldehyde C-14 because it is not an aldehyde, it doesn’t even decompose to an aldehyde. The nomenclature craziness continues as a smaller lactone, gamma-Nonalactone, is called Aldehyde C-18 and also called Coconut Lactone. This kind of confusing way of referring to the molecules drives the chemist crazy. Don’t even get me started on Aldehyde C-16 which is neither lactone or aldehyde nor structurally similar to the two above.

Peach Lactone is the key ingredient in one of the best perfumes of all time, Jacques Fath Iris Gris. Dawn Spencer Hurwitz used it as a key component of her reconstruction of this fragrance for her recent Scent of Hope. Peach Lactone forms a gauzy fruity layer carrying smooth creamy components. Peach Lactone is also found as the source of that fruit in Guerlain Mitsouko. In almost every great case I can think of if you smell peach in a perfume this is probably the chemical behind it.

massoia lactone

One of the most amazing uses of lactones has come recently in 2011’s Hermes Hermessence Santal Massoia by perfumer Jean-Claude Ellena. M. Ellena takes Massoia Lactone and uses it to bridge the natural creamy qualities of fig and sandalwood. Massoia Lactone besides the creaminess also has a rich caramel aspect and it is this which creates a dulce de leche accord in the middle of Santal Massoia.

If you smell fruit and cream in your perfume it is lactones which are probably responsible.

Mark Behnke

New Perfume Review DSH Perfumes Scent of Hope- Jacques Fath Iris Gris Reincarnated

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Some of my favorite interactions in my perfume career are with independent perfumer Dawn Spencer Hurwitz. We have spent most of our time together walking, sniffing, and talking about perfume. We have chattered about the reality of vintage perfumes and which fragrances we think are the best ever. One we both agree belongs in that category is Jacques Fath Iris Gris. I know for myself it is the benchmark an iris fragrance has to live up to for me to think it extraordinary. Finding a bottle these days is a very expensive proposition.

One of the things I admire so much about Ms. Hurwitz is she spent the early part of her independent career reconstructing the great fragrances of the past. She is a believer in the adage that says to study an art form you must also try and reproduce it. That stage of her development is long past and now she is on the top tier of independent perfumers in the world. Earlier this year one of her clients who was fighting cancer asked Ms. Hurwitz to make an exception and to recreate Iris Gris for her. Through a happy confluence of events Ms. Hurwitz agreed. This has been named Scent of Hope.

Iris Gris_JacquesFath

Ms. Hurwitz has always let us into her creative process and for the task of making a new Iris Gris it was no different. On her blog DSH Notebook there are three parts about the whole process behind Scent of Hope and if you’re interested in the process I highly encourage you to read Part 1, Part 2, and Part 3. The two things I took from those posts was how Ms. Hurwitz didn’t just take some of her original Iris Gris and get it analyzed. Instead she looked to two invaluable resources in the fragrant blogosphere; Barbara Herman and Octavian Coifan. Ms. Herman has been writing about perfume for many years at her blog Yesterday’s Perfume and she recently published a book “Scent and Subversion”. M. Coifan was the iconoclastic voice behind the now-defunct blog 1000 Fragrances. M. Coifan had exquisitely used his own nose to dissect Iris Gris and this gave Ms. Hurwitz a framework to start from. Ms. Herman has a way of using words to make a fragrance seem to arise from the computer screen. When I eventually try something she has described I find her description to be spot on. The second thing is Ms. Hurwitz let her nose and her client’s nose as well as their skin be their guide on when Scent of Hope was done. The scent strips were dispensed with and they let their feelings guide them to a final product.

DSH

Dawn Spencer Hurwitz

How did they do? I’ll cut to the chase; fantastically well. It is only the use of a couple of modern equivalents which give away Scent of Hope’s contemporary birth. The genius of Iris Gris is the use of a particular aromachemical called aldehyde c-14 which is not an aldehyde but a different chemical class called a lactone. This lactone imparts a gauzy peach veil over the entire composition of Iris Gris and Ms. Hurwitz had to work with it in Scent of Hope. The trick is not to let the iris blunt this shimmering layer but to somehow support it as if you are looking at an iris through a peach colored scarf. If the balance is off the whole thing falls apart. Ms. Hurwitz’s previous experience studying the great perfumes had to come into play here because she manages this with what seems preternatural ease. Based on her blog posts she reached the finished product in very few mods.

I compare my bottle of Iris Gris and Scent of Hope and these are very close. The aging process has made the orris suppler in Iris Gris. In Scent of Hope it still has a lot of its chill and steel on display. What is absolutely identical is the use of aldehyde c-14 to caress and float above the iris. That is recreated perfectly. Scent of Hope lacks a bit of the animalic bite of the original mainly because those raw materials are no longer available. Even so Ms. Hurwitz has chosen a good group of modern musks to come very close. It is right here where the biggest difference between original and modern versions are apparent.

Ms. Hurwitz is a unique combination of passion and precision; both of those qualities were necessary to produce Scent of Hope successfully. This is a great iris fragrance and if you love iris you want to own this.

Disclosure: This review was based on a sample provided by DSH Perfumes.

Mark Behnke

Editor’s Note: 30% of the proceeds of Scent of Hope will go to a Denver-area support center for those battling breast cancer called, “Sense of Security”.