[caption id="attachment_3404" align="alignleft" width="300" caption="Rose de Rescht"]
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The best way to smell a rose? Cut the bloom and put it into the warm bowl of your hands. Breath warm air into the flower and then inhale deeply.
The best time to do this smelling? A damp morning after a night of gentle rain, when the sun has been up long enough to dry the the earth, and the petals and to have played gentle rays on the plant.
The basic substances behind scent are called glucosides, produced in the plant cells through the action of chlorophyll. The sap then transports them to the petals. Here in petals they are hydrolized into glucose and rose alcohols. These are then oxidized. The strength of the perfume depends on weather conditions, soil type and how developed the flower is.
There are 7 defined rose scents: nasturtium, rose, orris, violet, apple, lemon and clove.
The rose one has its standard in
Rosa x damascena ‘Kazanlik’ - from a mountain valley Bulgaria. The theory is that a compound rosenoxide is manufactured in sunlight by the catalyic action of the pink or red pigment in the petals. You can smell this rose at 20 paces. This damask odour is confined to red or pink roses.
As a source of information, I am relying on EB le Grice, a much vaunted rose grower from Norfolk who died in 1977. No doubt science has moved on, so I stand to be corrected.