What is the Perfume Project?

This blog is a constantly evolving forum for thoughts on perfume, perfume-making, plants (especially orchids and flora of the Pacific Northwest) and life in general. It started out chronicling the adventures of Olympic Orchids Perfumes, established in July 2010, and has expanded in other directions. A big part of the blog is thinking about the ongoing process of learning and experimentation that leads to new perfumes, the exploration of perfumery materials, the theory and practice of perfume making, the challenges of marketing perfumes and other fragrance products, and random observations on philosophy and society. Spam comments will be marked as such and deleted; any comments that go beyond the boundaries of civil discourse will also be deleted. I am grateful to all of you, the readers, who contribute to the blog by commenting and making this a truly interactive perfume project.

Wednesday, January 3, 2018

MATERIALS WEDNESDAY: ABSOLUTES

I need to resume the Wednesday series on perfume materials. Given that it’s a new year and I beat resins to death over the last couple of years, it’s time for a new theme. I think most people have an easier time relating to natural materials than to aroma chemicals, so I’ll stick with those until I’ve exhausted the possibilities, if that’s even possible.

A couple of days ago I was mixing an all-natural formula that uses a lot of absolutes, so I decided that the next chapter will be on absolutes. Everyone talks about absolutes and sometimes lists them in perfume notes, but I’m not sure everyone knows exactly what they are and how they are obtained.

Steam distillation and cold-pressing are relatively familiar processes, but many materials do not lend themselves to distillation, and even fewer to cold-pressing. For these materials, the aromatic constituents must be obtained using other methods. In the old days, this was done using enfleurage, the original form of solvent extraction that could isolate the delicate volatile molecules contained in flowers like jasmine and gardenia. In this method, flowers or other materials were layered with solidified meat fat and left until the fat-soluble molecules had diffused into the fat, or added to heated fat in sequential batches until the fat was sufficiently scented. The fat could be used as a “pomade”, or the scent components could be further extracted with alcohol. The alcohol would evaporate over time, leaving the fragrance components, or the absolute. Some artisan perfumers will occasionally still use enfleurage to make small batches of perfume.

The modern method for solvent extraction is similar to enfleurage in theory, the difference being that instead of meat fat, hexane or another lightweight organic solvent is used for the initial extraction. The solvent is then siphoned off, leaving the initial round of aromatic molecules behind, trapped in a waxy base. This first extraction product is called the “concrete” because it is somewhat solid in form. Because the concrete contains naturally-occurring waxes and other materials in addition to the desired aromatic components, it is sometimes sold comparatively cheaply for use in creams, lotions, and solid perfumes, or for further extraction.

The next step is extraction of the concrete with ethanol, similar in theory to tincturing. The odorant molecules will diffuse into the alcohol, leaving behind the water-soluble molecules, waxes, and other contaminants. The process of separation is facilitated by freezing or chilling, which solidifies the unwanted substances leaving the scented alcohol. The alcohol solvent can then be removed by evaporation or low-temperature distillation, leaving behind the desired fragrant substances in concentrated form.  


Using current methods, absolutes contain vanishingly small amounts of the solvents used in extraction and are therefore considered fully natural if obtained from a reputable source. 

[Photos from Wikimedia except floral concrete, from a supplier's website] 

9 comments:

  1. I purchased a Rosa Damascena Absolute about a year ago and was wondering if there is an optimal way to store it. Obviously it was pretty expensive and I want to prolong the quality as long as possible. I don't use it that frequently and considered keeping it the refrigerator or even frozen instead of room temperature. Do you think that would help, hurt or have no effect on the shelf-life?

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    1. Anne, I think that unless your room temperature gets very hot, the absolute should be fine. Just keep it tightly capped and out of direct sunlight. You could store it in the refrigerator (not freezer), but the absolute might solidify. To use it, you could just warm it back up to room temperature, and it should liquefy again. How are you using the Rosa damascena absolute?

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    2. I've used a drop or two to scent DIY serums and oils/moisturizers. I also made a rollerball of absolute diluted in carrier oil to use as a soliflore or layer with other essential oils or amp up the rose in existing fragrances. Thanks for the recommendation.

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  2. Thank you for continuing this series of posts! Great information.

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    1. Azar, thanks! This series is fun to do.

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  3. Wow, the dedication required for this art is amazing!

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    1. Yes, there is dedication at every stage of the process.

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  4. My favorite absolute is nutmeg! It's just incredible, and I've only found one chunk of it. Though it may well be a concrete mislabeled as an absolute, since it is, in fact, a waxy lump. I use little chips of it for incense. It's about 15 years old and smells as good as the day I bought it. What are your favorites?

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    1. Marla, I haven't tried nutmeg absolute, but do have the CO2 extraction. It's very close to the real thing. What you have might be the concrete. I'm not sure what my "favorite" absolutes are because different ones are best for specific purposes. Your 15-year-old nutmeg sounds amazing!

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