When embarking on the perfumery journey, aside from the oft confusing maze of terms, ingredients and techniques, there is the inevitable discovery that some perfume materials are extremely powerful, especially when we’re speaking of aroma-chemicals. Sometimes, the mere trace of an aroma-chemical can be enough to throw your entire formula out the window. But aroma-chemicals do not hold the copyright on formula invaders; some essential oils can also join that party. A little too much Angelica Root and you wish you had thought twice. Aroma-chemicals are much stronger than essential oils, so much so that I keep mine stored in a different room from the one in which I do my perfume creation. And the room I keep these materials in has an exhaust fan!
I tend to see beginners in various groups and forums discuss their fear of working with strong fragrance materials, such as Aldehydes. The way to dispel that fear is hands-on practice. In my site and blog posts I often recommend the book The Formulation and Preparation of Cosmetics, Fragrances and Flavors, by Louis Appell. In part, I recommend his book because of the generous amounts of formulas that he offers for the recreation of some well-known vintage perfumes. However, the main reason I recommend it is because you can learn quite a bit by actually following his formulas, especially when it comes to working with difficult (for some people, scary) ingredients like aldehydes, benzaldehyde (Bitter Almond), Eugenol, Cis-3-Hexenol, Civet, etc. Some aroma materials are so incredibly strong that even a 0.001% dilution can affect your formula. Geosmin is such an example. It is so strong, in fact, that it is often sold as a 1% dilution, one which you’ll eventually dilute further. Often, these materials are labeled for sale with an odor strength level: high.
As I mentioned previously, I spent the first year or two of my perfumery journey following Appell’s formulas, while doing other research, to learn and discover more about the use of essential oils and aroma-chemicals in perfumery. By following Appell’s formulas, I was able to work with materials like Eugenol, Oakmoss, various aldehydes and many other components often considered strong and in need of careful dosing. Not to mention, recreating many of Appell’s bases (and others, such as Poucher’s), I learned much about what makes a rose, or a gardenia, or jasmine, smell the way they do. Of course, the research does not end there. Appell’s formulas are generally vintage, which means you’d be creating perfumes and bases the way they used to be, but in later decades the discovery of new aromatic materials and changing trends, coupled with more and more regulations, have changed dramatically the way perfumes smell. The current Chanel № 5 does not smell the way Chanel № 5 smelled in the 1940’s, 1960’s or 1980’s. The beauty of starting off learning vintage perfumery is that your knowledge progresses as you move forward, and it is ongoing. Other books offer more formulas and extensive information on modern perfumery. I list some of those books here.
Another great way to figure out how some materials are used in various formulas is by looking at formulas offered in The Good Scents Company website. Let’s look at various Floral formulas by clicking the link below (which should open as a new window).
Following the link above you can see various floral formulas, starting with a base made only of aldehydes to be used in various other floral formulas. When you peruse this particular page, you will see aldehydes listed in some of the other formulas. Take a look and compare how these are dosed. You can do the same with any aromatic material and compare it against many of the formulas on that site to see how these are often dosed.
After you work extensively on creating more and more formulas, whether bases, accords or full perfumes, you will begin to feel more comfortable with using strong materials. Aldehydes, for example, are often used at a 10% dilution, sometimes as low as 1% and once in a while at 100%. You can only make those decisions once you have learned more about these materials, worked with them for a while and discovered for yourself when you’ve gone too far (legend has it this is how Chanel № 5 came to be…….). Following tried and tested formulas, however, will help you feel more at ease with these materials, because you’d be using them knowing someone else knew what they were doing. You experience the results firsthand, which at the same time helps you realize what these materials smell like, when well dosed, in a formula. Your nose and your brain take notes that you will use again and again. Eventually, you’ll come to a point where you won’t think twice when using an aldehyde for brightness (or a citrus or floral twist), choosing Eugenol to warm your formula, or adding a bit of a spicy herbaceous note with Angelica Root.
As an aside, and possibly a subject for a whole other post, some materials need to be kept refrigerated. Aldehydes are notorious for ‘going bad.’ Luckily, most aldehydes are not expensive and the loss is not painful on the wallet, but I generally will dilute these largely at 10% in perfumer’s alcohol, smaller quantities at 1%, and then keep them refrigerated. In dilution and refrigerated, they keep well. I do keep a quantity at 100% for the rare occasion I will need them at full concentration, but I am prepared to be tossing them out at some point. Citrus oils (i.e. Lemon, Orange, Lime, Bergamot, Citral) are also best kept refrigerated. I also keep the various Ionones in the refrigerator. Many green materials, like Helional, Lilial and Nonadienal (hint…the al in their names reveals these are aldehydes) are also kept refrigerated as are animal derived materials such as Civet or Castoreum. Bitter Almond oil (which is 99% benzaldehyde) is another one I also dilute and keep refrigerated as it can go bad relatively quickly, and is usually used in dilution.
Eventually you’ll get a handle on what may need refrigeration and what is OK sitting on your shelf at cool temperatures and away from strong, direct light. I do recommend you purchase a small refrigerator (a 4.4 cu.ft. one will do) for perfumery use and keep these materials not in your food refrigerator. The scent from these materials is so strong that it will permeate your food if kept together in the same fridge. They are so strong, in fact, the refrigerator you purchase for perfumery use will retain the scent for a long time if you decide to use it for something else.
To sum it all up, my suggestion is to go forth without fear and embrace these strong fragrance materials that, correctly dosed, will lend much beauty to your perfumery formulas. Do not avoid them. Learn how to work with them and soon you won’t imagine your perfumery journey without them. As the saying goes, ‘you’ll never leave home without them.’