Blackcurrant, or cassis, is one of the fruitiest of top notes odorants used in fragance chemistry. A team in Germany has now taken a close look at the gas phase structure of odor molecules that smell of blackcurrant, including the archetype cassyrane. Microwave spectroscopy reveals much about what stereochemical characteristics are linked to this distinctive odor used in perfumes such as "DKNY Be Delicious." Understanding which isomers and which hydro derivatives share the scent or deviate into the smell of Provencal herbs, such as rosemary, can help fragrance chemists design novel odorants for the next fashionable fragrance.