Whether we like them or not, roses in perfumes are ubiquitous. They support other florals and lend a general sense of body to a perfume.

Most rose notes are now added with synthetics, but almost always a small amount of natural rose is added for support. Rose extracts come in five forms: otto (oil), absolute, concrete, CO2, and enfleurage.

Rose otto is a byproduct of distilling roses with water, yielding large amounts of rose water. When the rose water comes off the still and is allowed to settle, a thin oil slick appears. This is the otto and is very powerful and expensive. It does, however, go a very long way, making it one of the more viable naturals for use in a modern perfume. An otto, however, does not capture all of the scent of the rose, because the water-soluble components (mainly phenylethanol) are left behind in the rose water. A more complete picture can be achieved with rose absolute.

Rose absolute is prepared by extracting rose petals with hexane or ethyl ether and letting the hexane or ether evaporate. This leaves behind the solid concrete which contains not only the aromatic components, but also, waxes and other compounds that help fix the rose and make it last. When the concrete is extracted with alcohol and the alcohol evaporated off under vacuum, there remains the absolute. The absolute has an intense aroma of rose.

While less common, two other methods are used for extracting the essential aromas of roses. One is COextraction—liquefied carbon dioxide is used to “distill” the roses in a cold process—and another is enfleurage, in which the petals are placed on trays of solidified fat until the fat is permeated with the roses. The fat is extracted with alcohol, the alcohol evaporated, and there remains the enfleurage. The enfleurage is similar to the absolute, but even more delicate and complex.