Experts have proven that each Bulgarian rose has oil in every part of the flower, but with different properties.
For example: rose oil located in the calyx is richer in free alcohols and stearoptenes, while in the other parts of the flower there are more esters and other compositions.
Numerous observations have also proven the difference in oil content and properties in a full 24 hours cycle, despite weather conditions. At the same time meteorological conditions play a crucial role and affect the development of the rose flowers and the accumulation of oil in the stems and calyx.
What makes the Bulgarian rose oil so unique with peerless aroma is the proper timing to harvest and control the production of the final blend of the various oils from the flower.
Rosa Damascena Mill is the only botanical source used to produce Bulgarian rose oil.
The production of 1 kg of pure rose oil requires 3,500 kg rose flowers.
The chemical composition of the rose oil is very complex – it includes alcohols (such as citronellol, geraniol and nerol), esters, free acids, aldehydes, ketones, phenols and phenol ethers, hydrocarbons and stearoptenes.
The present standard of high-grade Bulgarian rose oil is as follows:
Phyto Compositions, Content, %
1. Ethanol Up to - 3,0
2. Linalool from - 1,0 to 3,0
3. Phenyl alcohol Up - to 3,0
4. Citronellol from - 24,0 to 35,0
5. Nerol from - 5,0 to 12,0
6. Geraniol from - 13,0 to 22,0
7. Geranyl acetate - Up to 1,5
8. Eugenol - Up to 2,5
9. Methyl eugenol - Up to 2,0
10. Farnesol Not less than 1,4
С 17 /heptadecane/ - from 1,0 to 2,5
С 19 /nonadecane/- from 8,0 to 15,0
С 19 /nonadecene/- from 2,0 to 5,0
С 21 /Heneicosane/- from 3,0 to 5,5
С 23 /tricosan/ - from 0,5 to 1,5
Other indexes include:
Color - Yellow to yellowish-green
Odor - Typical of rose oil
Specific gravity at 30 C - 0.848 to 0.861
Refractive index at 25 C - 1.4530 to 1.4640
Optical rotation in 100 mm tube - -2.2 to -4.6
Congealing point - 16.5 to 23.5 C
Acid number - 0.92 to 3.75
Ester number - 7.3 to 17.1
Saponification number - 8.0 to 21.0
Acetylation number - 202.6 to 244.8
Free alcohols, like geraniol - 62.9 to 75.5 %
Combined alcohols, such as geraniol - 2.0 to 4.7 %
Total alcohols, such as geraniol - 64.9 to 78.2 %
Stearoptene - 15 – 23 %