Film vs. Fact – Distilling human essence? (part 3/4)
This post continues with assessing the factual accuracy of the perfume references in the script of the German TV show Parfum, made for Netflix. Each episode of the first series begins with a statement about perfume and how we perceive it. The statements, within the parameters of the plot about desire and murder, are generally in line with how perfume and the sense of smell actually work. In the previous posts, I discussed the script references to Ambra (ambergris), Skatol (skatole) and Synthese (the synthesis or composition of a perfume). In this post, I discuss the next element, The Third Substance, which is about the distillation of perfume.
Screen shot from the series Parfum.
“The Third substance”
“It’s easy to discover a scent you love.
A rose petal, the hair of a child, forest soil in summer But it is difficult to separate that scent from the surrounding matter.
It can’t be elicited.
It can’t be released by force.
Perfumers use alcohol to extract the waxy fragrance from the body.
Benzene, then, separates the scent from the wax.
A separation cannot be executed between just two things.
A third substance is necessary.” (Extract from the script of Parfum)
Commentary
The script writers are talking about the perfume distillation process, but they get two methods, using alcohol and using benzene, mixed up.
As to the question, can you extract the essence of a human’s skin and bottle it, like they do in Parfum and in Süskind’s novel? Well, if you can use enfleurage on a living human, in theory you could. Sounds utterly revolting though, and plain impracticable. In theory, you could bottle any smell from anything as long as you can extract and preserve the essential oils in it – even old books.
However, “…to capture and preserve human scents are indeed tricky. But it can still be done without having to kill your ‘ingredient’. Artists Yeb Wiersma and Lotte Geeven captured the essence of the city Rabot, in Ghent, Belgium, by collecting the sweat and scent from t-shirts worn by 100 residents of Rabot.” This preservation was done through a distillation process, rather than enfleurage, in their project called Diffusion: Essence de Rabot. (Valienska Magfira, Capturing human scent through enfleurage, source: mediamatic.net, rtrvd. 2019-03-14)) And, in a collaboration between the Institute for Art and Olfaction in Los Angeles, US, and the Dutch MediamaticArt Olfaction Amsterdam programme, artists did in fact do enfleurage on a willing test subject in 2018.
Fragrance extraction refers to the separation process of aromatic compounds from raw materials, using methods such as distillation, solvent extraction, expression, sieving, or enfleurage. The results of the extracts are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product.
Certain plant materials contain too little volatile oil to undergo expression (squeezing the oils out), or their chemical components are too delicate and easily denatured by the high heat used in steam distillation (steaming the oils out). Instead, the oils are extracted using their solvent properties.
Copper still from 19th to 20th century Grasse, France for steam distillation. (Image: Fragonard)
Extraction using volatile solvents such as hexane and ethanol consists of dissolving the fragrance-bearing part of the plant in a solvent which is then evaporated. (Image: Fragonard)
Organic solvent extraction is the most common and most economically important technique for extracting aromatics in the modern perfume industry. Raw materials are submerged and agitated in a solvent that can dissolve the desired aromatic compounds. Commonly used solvents for maceration/solvent extraction include hexane (C2H6O or methoxymethane, a colorless gas), and dimethyl ether.
Hexane is made from biogas from biomass, or naturally-occurring methane, or natural gas. Hexanes are significant constituents of gasoline. They are all colorless liquids, odorless when pure, and are widely used as cheap, relatively safe, largely unreactive, and easily evaporated solvents. Hexanes are chiefly obtained by refining crude oil. (I think that’s where the script-writers got mixed up with “benzene”.)
In organic solvent extraction, aromatic compounds as well as other hydrophobic (doesn’t take to water) soluble substances such as wax (for instance from the human body or animals) and pigments are also obtained. The remaining waxy mass is known as a “concrete”, which is a mixture of essential oil, waxes, resins, and other lipophilic (oil-soluble) plant material.
Another type of solvent, often ethyl alcohol, must be used to extract the fragrant oil from the “concrete”.
The alcohol is removed by a second distillation, leaving behind the “absolute”. (This is what the script refers to as using alcohol to extract the ‘wax from the body”.) These extracts from plants such as jasmine and rose, are called “absolutes” or in perfume names, “absolue”.
Supercritical fluid extraction is a relatively new technique for extracting fragrant compounds from a raw material, which often employs Supercritical CO2as the extraction solvent.
Extraction using ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol, with the chemical formula C2H5OH) is a type of solvent extraction used to extract fragrant compounds directly from dry raw materials, as well as the impure oils or concrete resulting from organic solvent extraction, expression, or enfleurage. Ethanol extracts from dry materials are called tinctures, while ethanol washes for purifying oils and concretes are called absolutes.
Steam, Dry or Fractionation Distillation is a common technique for obtaining aromatic compounds from plants, such as orange blossoms and roses. The raw material is heated and the fragrant compounds are re-collected through condensation of the distilled vapor. Distilled products, whether through steam or dry distillation are known either as essential oils or ottos.
Expression as a method of fragrance extraction where raw materials are pressed, squeezed or compressed and the essential oils are collected. This is where the phrase “cold-pressed” comes from.
Enfleurage or absorption: The absorption technique is based on the ability of animal fat to naturally absorb odours. Depending on how well the plant matter withstands heat, this process can be conducted at either hot or cold temperatures.
“Hot absorption or maceration consists of steeping flowers or other scent-bearing materials in previously heated fats or oils. This mixture is then filtered through fabric to obtain scented unguents. These perfumed pomades are then mechanically washed in alcohol, after which the alcohol, now perfumed, is separated from the fat. This technique, practised since Antiquity, has been complemented over the centuries by the development of other extraction methods.
Enfleurages (Image: Fragonard)
Since fragile flowers such as jasmine, tuberose and daffodil cannot withstand heat, the technique of cold absorption was developed. This technique was very common in the Grasse region until the first half of the 20th century. Cold absorption consists of spreading a layer of cold odourless fat onto sheets of glass held in frames; this fat is then covered with flowers that are regularly replaced with fresh ones until the fat is saturated with fragrance. These perfumed pomades can either be used to manufacture cosmetic products or mechanically washed in alcohol to eliminate the fat, after which the alcohol is evaporated to obtain absolute.” (Source: fragonard.com)
Image credits for header:
pexels-photo-209513 Image by: Pixabay, Pexels License CC0 ✓ Free for personal and commercial use ✓ No attribution required
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