Extraction is done by dipping the flowers in alcohol or fat.
As the fragrance is concentrated in the petals, it is essential to pick the flowers at the right time, not too early or too late, in the season. The flowers are picked in the morning, just after the dew, between the end of the night and the sunrise. The petals must be immediately recovered for treatment. That's why the perfume factories are located near the flower fields. In France, the majority of these factories are located in the South.
To extract the perfume, it is necessary to "remove" it from the petals. To do this alcohol is used, the perfume is then dissolved in alcohol. It is then sufficient to concentrate everything by distillation. We can also put the petals of the flowers on a fatty body that absorbs the perfume and then melt and filter this fat.
The making of perfume requires a lot of flowers. For a liter of rose scent, 800 kg of petals must be collected, which represents more than 10,000 roses. That's why perfumes are expensive!
A section produced in partnership with the Espace des Sciences in Rennes.