Description and usage notes:
This chemical is the key component of the natural vanilla odour and is characteristic of vanilla based scents and flavours. In this form it is one of the most widely used of all perfumery materials, used in all types of fragrance in small doses. Vanillin comes as white to cream coloured crystals, that dissolve readily at low doses in most perfumery materials and in ethanol. High doses can become sickly-sweet and amounts above 8% of the perfume concentrate are rarely used. It has some useful fixative qualities as well, particularly with floral materials. See also ethyl vanillin, propenyl guaethol and Isobutavan for materials with related odour profiles.
Arctander writes very extensively about vanillin and some extracts are presented here: “Among the more common perfume materials, Vanillin is one of the most tenacious odors known.”; “Its intense sweetness is utilized in industrial masking odors and in high-cost luxury perfumes, and it can be used in almost any type of fragrance, from woody or herbaceous to Oriental or floral.”
He also points out that because vanillin is such a high volume product it is chemically one of the purest materials used in perfumery. This together with improvements in base products mean that the use of low doses of vanillin in fragrances for functional products such as white soaps and creams is no-longer the hazard it once was, though discolouration can still occur where higher amounts are involved.
Jean Claude Elena, in his book Diary of a Nose, suggests that in combination with Isobutyl Phenyl Acetate this material can produce an effective illusion of the smell of chocolate and says “To ‘make’ plain chocolate, I recommend adding patchouli; for a ganache a trace of civet; for ‘orangette’, orange zest; for an After Eight, spearmint; and for the smell of cocoa powder, concrete of iris.” We suggest that you might substitute l-Carvone for the spearmint to avoid solubility problems, and Orris Givco for the concrete to avoid needing a second mortgage. You could also experiment with Ethyl vanillin which is much stronger but often perceived as more chocolatey than vanillin.
Additional ideas for a more authentic chocolate or cocoa accord are mentioned in the Cocoa Hexenal product description.