With the curiosity of a scientist and the writing skills of a master story-teller, Amy Stewart is one of my favorite authors. In her 2013 New York Times best-seller The Drunken Botanist, she explores the hundreds of “plants that create the world’s great drinks,” from barley and hops to obscurities such as quandong, sloe berry, and even a couple of centuries-old iris:
“The pharmacy and perfumery of Santa Maria Novella, established by Dominican friars in Florence in 1221, gained notoriety for its use of the rhizomes of iris. They were not the first – Greek and Roman writings mention it – but their perfumes, cordials, and powders contained liberal doses of this rare and precious substance.
“Orris was popular not so much for its fragrance – although it does contain a compound called irone that gives it a faint violet smell – but as a fixative, holding other fragrances or flavors in place by contributing a missing atom that would otherwise make the fragrance volatile and easily released from the solution it is suspended in.
“None of this chemistry was understood at first. Perfumers and distillers would also not have understood why the rhizomes had to dry for two to three years before they become effective as a fixative. We now know that it takes that long for a slow oxidation process to occur, . . [which] causes irone to form . . . .
“Only about 173 acres of orris are cultivated worldwide. Most of the orris is either I. pallida ‘Dalmatica’, grown in Italy, or . . . I. germanica var. Florentina, grown in Morocco, China, and India. I. germanica ‘Albicans’ is also used . . . .
“To extract the orris, the rhizome must first be pulverized and steam-distilled to produce a waxy substance called orris butter, or beurre d’iris. Then alcohol is used to extract an absolute, which is . . . a stronger version of an essential oil.
“Orris is found in nearly every gin and in many other spirits. Its popularity in perfume is due to the fact that it not only holds the fragrance in place but clings to the skin as well. It also happens to be a very common allergen, which explains why allergy sufferers might be sensitive to cosmetics and other fragrances – as well as gin.”