SUBSTITUTION AND DILUTION — TWO NECESSARY EVILS IN IFRA-SAFE PERFUMERY
Sharing with us the secrets of perfumery, Thierry Wasser has re-created fifty-three historic Guerlain perfumes. He reveals that some of the most unwelcome restrictions of the IFRA guidelines are on nitro-musk and raw bergamot oil. Both of these materials, serving as a base and a top note respectively, provide much of the richness, roundness and depth that we know from vintage Guerlain. In comparison, the "purified" substitutes that are allowed today smell dry, flat and one-dimensional.
Other than substitution, a second method to make a formula meet the IFRA criteria is by diluting the fragrance until the concentration of the most problematic ingredient falls below the safety threshold. That’s the reason why nothing but very light EdT versions of Mouchoir de Monsieur, Après l’Ondée and Chant d’Arômes exist today. Only by ingenious and painstaking work in the laboratory has Wasser been able to preserve the more concentrated Parfum versions of the Guerlain catalogue’s remaining classics, although these also appear lighter and less tenacious next to the re-created originals. Thierry Wasser explains that dilution can radically change the olfactive impression of a fragrance, even when the formula itself is unaltered: a diluted fragrance doesn’t just smell less intense, it smells different. That’s because dilution affects some notes more than others, hence tipping the balance of the composition.
Most often, the methods of substitution and dilution are used in combination when reformulating a fragrance. We therefore understand the mechanisms that make several of today's versions of Guerlain classics pale in comparison to how they originally smelled. Read more about the re-created vintage Guerlain perfumes
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