Geosmin and Petrichor: The Perfume of the Earth

Most people know wild carrot as Queen Anne's Lace. The gnarled weedy beginnings of its flowers illustrate the plant's invasive nature, but when these flowers mature they are surprisingly beautiful. The mathematical precision of its white florets are as compelling as a computer generated fractal. The taproot of Queen Anne's Lace is fibrous, sizable and strong. Anyone who has ever pulled up these plants knows that resistance is part of the weeding game, but an interesting gift is bestowed upon the nose for the effort; the root-tinged aroma of geosmin that accompanies the smell of underripe carrots.



When exploring the story of geosmin one cannot avoid a spiritual encounter with the narrative of human terroir. According to the Abrahamic faiths of Judaism, Christianity and Islam we are all made from dirt and destined to return from whence we came. Whether you call it dirt, earth or soil, each are one and the same. This deceptively simple substance allows plants and livestock to flourish, which in turn provides sustenance at our tables. When we shed our mortal coil the earth welcomes our body back and transforms what remains into new life for organisms that will come to life in the future. Gardeners and farmers are particularly conscious of this fact and for them the smell of geosmin in freshly turned earth is the very essence of life.

In the lab geosmin is known by its molecular name; Dimethyl-9-decalol. Geosmin present in the spore coat of actinomyces and streptomyces soil bacteria, which is released into the air before the first rain falls on dry earth, is known as petrichor. In this scenario geosmin is atomized like a perfume and lingers as a soil-water aerosol. In the Eastern tradition of attar making there is a natural perfume inspired by petrichor. It is created by distilling sun-baked earth with sandalwood. It is called Mitti Attar and resembles the smell of the first monsoon rain on parched soil.

It is no surprise that the mystique of geosmin has given birth to several perfumes built around this enchanting molecule. The Smell of Weather Turning by Lush is a handsome interpretation of geosmin expressed in petrichor. It is a slightly chilled fantasy of petrichor where geosmin is supported by oak wood, hay, beeswax, nettle, English peppermint, mint and Roman chamomile. It is a tad woody and the understated cooling aspects make geosmin, an assertive and cloying molecule, more nose-friendly.

Demeter Dirt takes a different approach to geosmin-inspired perfumery with its simple yet hauntingly diaphanous architecture. It includes geosmin, methyl dihydrojasmonate (the floral compound known as Hedione) and transparent musk (the later supporting an uncanny effect that resembles the smell of "just washed" hair). Add a human pulse and Demeter Dirt transforms into a living entity with a subtle sillage capable of breaking your heart into a million pieces should the human censer suddenly disappear. For hardcore geosmin lovers who don't care for olfactory window dressing there's Demeter Beet Root. It smells like its name and has a sweet rouged quality that tempers geosmin with a vague hedonic quality.

If the idea of wearing a geosmin inspired fragrance doesn't resonate with your notion of haute perfumery there's good news. It's July and wild carrots are in season. Now is the perfect time to give a sturdy stalk of Queen Anne's Lace a good yank* and have yourself a sniff or two. Don't be shy. You can take a stealth sniff of the aromatic taproot when no one is looking and pretend you're a naturalist.

Notes:

Composer Adam Neal Scott wrote Petrichor, an experimental ambient music composition. It can be heard in its entirety and downloaded for free online. Listen to it on your i-Pod if you decide to go wild carrot hunting and indulge in a multisensory experience of your own making. P.S. Glass Petal Smoke recommends making a donation when you download Scott's music. 

Geologists I.G. Bear and R.G. Thomas coined the term Petrichor in 1964. It can be found in their paper, "Nature of Agrillaceous Odor." 

Glass Petal Smoke highly recommends Dirt: The Ecstatic Skin of the Earth by William Bryant Logan. It is a scientualist's delight and will make you think before you step on the ground.

The best Mitti Attar I've ever smelled is sold by White Lotus Aromatics. It is a seasonal product so you'll need to check on its availability.

The Smell of Weather Turning can be purchased at the LUSH website. It is available in a variety of sizes and is currently available in liquid and solid form.

Demeter Fragrances are available in a variety of retail stores. You can order their fragrances directly from their website.

"Making the Case for Beets," is a must-read if you want to understand the role that geosmin plays in the flavor profile of beets. Kudos to writer Susan Russo who has some interesting things to say on Food Blogga. You can follow Susan on Twitter.

You can read about Hedione and other marvelous aroma molecules in this article from the February 2009 edition of Chemistry World. 

Sarah Gordon is the artist that created the painting for The Smell of Weather Turning for LUSH. 

Photo of the wild carrot taproot is from Jone's Farmer Blog.  Rights revert back to the site. 

*If you decide to pull up a wild carrot or two make sure to wash your hands afterwards as a chemical component found in its leaves reacts with sunlight (a reaction known as phytophotodermatitis). Phytophotodermatitis is also caused by the molecule bergapten which is removed from Bergamot essential oil in IFRA-compliant perfumery.

Sumac: A Mediterranean Flavor Catalyst

Ground sumac is a flavor catalyst known for its acidulant qualities. It is used in Mediterranean dishes and has a subtle astringent tartness that is less assertive than pomegranate molasses or tamarind paste. Ground sumac's aromatic profile is a flavor subtext in za'atar, a spice mixture that generally includes: thyme, oregano, marjoram, sesame seeds, sumac and salt. Sumac tempers camphoraceous notes found in the assertive green herbs which comprise za'atar. It does so with naturally occurring malic acid, a molecule found in sour fruits. When you see an "E" before a number on a food ingredient list you are looking at a malic acid indicator. Malic acid is commonly found in sour candy and is what puts the "tart" in Sweet Tarts (an interesting scientific fact for budding gourmands).

Sumac's flavor profile may be sour dominant, but its fragrance tells another story. Harold McGee describes sumac as "aromatic...with pine, woody and citrus notes." Spice master Ian Hemphill elaborates on sumac's fruity qualities which he describes as "a cross between red grapes and apple, with a lingering freshness." The combination of McGee and Hemphill's descriptions complete the flavor profile for sumac and make it easier to identify whether or not ground sumac is fresh. If your nose detects the teint of rancid oil you have likely encountered old ground sumac as a bit of oil is sometimes used to keep the spice from clumping together along with salt. Fruitiness is the dominant quality you will notice when first smelling ground sumac. The depth of fruitiness will vary depending on where the sumac was harvested and the conditions under which it was processed and stored. 
















The tartness of ground sumac is immediately sensed when the spice is tasted neat. Sumac's fruity and pine-like qualities are best expressed simply; on a slice of fresh tomato. The malic acid in sumac makes the mouth water and intensifies the umami quality naturally present in tomatoes. This savory backdrop allows the pine-like freshness of ground sumac to express itself more fully, trilling the fruity aspects of the spice in an experience that is best described as a "flavor boomerang."
















Ground sumac is a brilliant flavor catalyst in parsley pesto. Glass Petal Smoke's Parsley Pesto with Sumac utilizes a combination of lemon zest and ground sumac to temper the assertiveness of parsley and garlic. Parmesan cheese isn't an ingredient in this recipe, but it can be added for enhanced flavor. Parsley Pesto with Sumac is divine on hot buttered bread, as an addition to sauces or soup stocks, and in fish dishes.

Parsley Pesto (with Sumac)
Recipe by Michelle Krell Kydd 
Yield: 1 1/4 cup

Ingredients:

• 1 bunch parsley (rinsed, long stems removed, chopped)
• 1 small head of garlic (chopped)
•  zest of one medium-sized organic lemon
• 1/4 cup walnuts (chopped)
• 1 1/4 teaspoon ground sumac
• 1/2 cup plus 2 tablespoons extra virgin olive oil (fruity type is a must for this recipe)

Instructions:

• Prepare ingredients for use in a food processor.
• Create several layers of parsley, garlic, lemon, walnuts and sumac.
• Add extra virgin olive oil once the layers are complete.
• Use a combination of chop and pulse settings on the food processor to achieve a paste, taking care not to munge the ingredients into a purée.
• Store in an air tight container in the refrigerator and/or freeze for future use. 

Notes: 

Ground Sumac is sold by several spice purveyors including Penzeys.

Malic is derived from the word malus in Latin which means apple. The aroma of malic acid in ground sumac bears a resemblance to tart apple skin. The red color of the spice reflects the presence of anthocyanins, the same flavinoid molecules found in berries. When it comes to taste anthocyanins contribute an astringent sensation and are generally flavorless. 

Photographs by Michelle Krell Kydd. All rights reserved.

Conversations With Ella: Lessons in Smell (Part I)

You know how people have five senses and how sometimes if they don't have one, another one they have is better and makes up for it? Like a blind person that can hear better because they can't see? I think my nose has two senses. One sense smells things that are too strong or aren't really there and the other sense smells nothing. But there are things in between that I can smell very well.--Ella (8-years-old)

When I first had a conversation with Ella it was in the basement of the First Congregational Church of Ann Arbor. I was telling her about Pseudonymous Bosch's book, The Name of this Book is Secret, and how the sense of smell figures prominently in the children's action adventure series. She was sitting with her mother Jennifer who had a look on her face that was a combination of interest and concern. "We think Ella might have a problem with smell."

People who can't smell favor trigeminal sensations like the coolness of mint, the heat of cayenne, and the tingling of carbonation. They are also sensitive to the messages the trigeminal nerve sends relating the texture of food and don't like things that feel unidentifiable (i.e. casseroles) or are texturally dominant in a way that does not give them pleasure along with their ability to detect taste (sweet, sour, salty, bitter and umami). Trigeminal sensations inspire emotion and memory with the same intensity that the sense of smell provides, so likes and dislikes in this area are visceral for those with sensory processing disorders and/or anosmia. When I learned that texture was also an issue for Ella our conversation about smell began:

     "I bet you really like peppermint."
     "I do! How did you know that?"
     Her voice was sweetened with glee. I appeared to be a magician.
     "You might have anosmia and that means you have trouble smelling things, but that doesn't mean you can't taste things. You might even taste things better than people who can smell."
     "So what's wrong with my nose?"
 
The weight of feeling different than others is hard for adults to bear. In children it can poke holes in their self esteem as they are sensitive to how they are perceived by others. I felt my brain searching for an answer, iterating in clicks like a computer that has received a command to retrieve a file that doesn't exist. I have written journal articles and given speeches to scientists, marketers and consumers on the subject of smell and perfumery, but never explained anosmia to a child. I answered from instinct and the wisdom instilled in me by my father, who was never patronizing when discussing adult topics with me as a child:

     "Did you ever see an old fashioned light bulb, the kind with a string that you pull to turn the light on?
     "I think so."
     "You have something called an olfactory bulb inside your head, at the top of your nose. There are many strings that can turn it on when you smell something. Each string turns on a smell. You might have fewer strings, different strings or no strings. Does that make sense?"
     "I think so." She hesitated as she thought to herself. "So what else does that mean?"
     Her tone was authoritative and vulnerable. I reminded myself that she was only eight years old.
     "The most important thing for you to remember is that you were made this way and that means you are very special; it doesn't make you a bad person. If you learn more about the way you sense things you will understand what makes you special. Then it doesn't matter what anyone else thinks or if they can understand it like you do. There's something else you should know. Someone you know and love has anosmia. Would you like to know who that is?"
     "Yes!  Who is it?"
     "Holly, your Sunday school teacher. Now you know there is someone who's a little bit like you."
     Ella said nothing. She just stood in front of me smiling. Looking at her was like staring at the sun.

In telling Ella about Holly's anosmia I was sharing something that few members at church knew, except for the staff. The words left my mouth of their own volition, but in retrospect it was compassion that prompted their escape. I saw Ella run up to Holly and hug her before we had our private chat about smell. It was the strongest affirmative example I could think of and was propelled by an instinct to protect her from feeling badly about herself. A lump formed in my throat. I took a sip of water to distract myself from the salt of withheld tears.

There's a saying in Buddhism; "When the student is ready the teacher will come." I've met with Ella on several occasions. The more we speak about smell clearer my role has become; I am both catalyst and student. Conversations with Ella teach me why I continue to find joy in perfumery and the science of olfaction. This is the first in a series of conversations about smell with Ella that will be featured on Glass Petal Smoke. I think you'll find she has some interesting things to teach us all.

First Lesson from Ella:

It's really how you look at difference that makes the difference. One can look at two roses, a yellow one and a red one, and favor one over the other for its color or perfume. It doesn't make either of them "less than" a rose. That kind of thinking is the way we exert our desire to have the world conform to our likes, dislikes and associated comfort levels. If you look at the condition of the world today you can see this in a lot of places; it is at the root of most social conflict.

In fragrance training the first thing we have to conquer is ourselves. First there is the Proustian response to aroma, the autobiographical memories, etc. Then there arises the need to understand the essence of what we smell, exit the realm of subjectivity and let the raw material speak to us. This is what I find so fascinating about smelling in perfumery. It has a way of heightening one's intuition, which cannot coexist with judgment. That is the compassion in smell. Perhaps this is one of the reasons I continue to be drawn to it. 

Notes:

A big thank you goes out to Ella's parents, Jennifer and Noah, for allowing me to share Ella's story. Ella's little brother Miles has been very helpful and patient as we work together to explore the sense of smell and taste with Ella. P.S. Miles asks great questions and has a sophisticated palate for a five-year-old; he loves sushi.

Photo collage of Ella and Barrett smell quote (later shot outside The Rubin Museum, in NYC) by Michelle Krell Kydd. All rights reserved.  

Photograph of Chocolate Chip Mint Ice Cream by TamDotCom via Creative Commons. Some rights reserved by the owner.

Image of mitral cells and olfactory bulb tissue by Sonya Giridhar via Carnegie Mellon.

Collage of artichoke flower and sensory pastel drawing from Spicelines and Two Shoes in Texas, respectively. 

Photo of lavender text overlaid with the image of a rose by Michelle Krell Kydd. All rights reserved. 

Inside the Olfactory Mind of Pseudonymous Bosch

If you don't know who Pseudonymous Bosch is then you: (a) know the underside of a rock quite well; (b) think that Harry Potter is the only kids' literature series that adults can tear through with the spirit of a child and/or; (c) consider Patrick Süskind's Perfume: The Story of a Murderer to be the last great piece of olfactory literature that has ever been written.

The time has come for you, dear reader, to take that soggy madeleine out of your grandmother's cup of linden blossom tea and get the heck out of Combray. (Terces Society members forgive me, but some who claim to be sensorial types are in fact imposters who obsess over smell and taste to deny their mortality and disguise their alchemical quest for everlasting life at everyone's expense.)

Pseudonymous Bosch is the author of the Secret Series of children's books. Each book in the five-volume action and adventure series is dedicated to a human sense. The Name of this Book is Secret is the first volume in the Secret Series and is thematically linked to smell. The plot includes a character with synesthesia, a variety of sophisticated olfactory references and a box containing precious fragrance vials dubbed "The Symphony of Smells".  If perfumer Christophe Laudamiel got a hold of The Name of this Book is Secret before it was published there would be a Symphony of Smells coffret at Aedes de Venustas and FAO Schwartz in perpetuity.

Pseudonymous Bosch agreed to take the Glass Petal Smoke Sensory Questionnaire after he was informed of the existence of Chocolate Voodoo Love Cookies. (The cookies were mentioned to persuade P.B. as chocolate is his weakness and a key ingredient in volume three of the Secret Series.) The recipe for the signature cookies (created by yours truly) will remain secret as will the identity of Pseudonymous Bosch.

What gives Chocolate Voodoo Love cookies their touch of je ne sais quoi? You'll have to ask writer Chris Belden, his wife Melissa DeMeo and their daughter Francesca (who after tasting chocolate repeated the word "more" until her chocolate mustache turned into a beard). The cookies are rumored to contain a love potion, but this can't be confirmed or denied. P.S. Fragrant Moments, Bois de Jasmin and several perfumers have partaken of said cookie, so you might want to ask them.

1.  What does your sense of smell mean to you?

I am told that what we think of as taste is mostly smell, and my sense of taste means everything to me. Hence, my sense of smell means most everything to me.

2.  What are some of your strongest scent memories?

What a curious question! I remember passing by some rather stinky weight-lifters who were obviously quite strong.  Also a few smelly but strong plough horses.

3.   What are some of your favorite smells (things in nature, cooking &/or your environment)?

I tend to like the smell of beans—baked beans, coffee beans, and of course chocolate beans.  I do not like the way beans smell after you eat them, however.

4.  Do you have any favorite smells that are considered strange?

Burning marshmallow?  S’more s’mores, please.

5.  Describe one or more of your favorite cooking smells.

Sometimes, the only thing better than eating chocolate is smelling chocolate being cooked—as hot chocolate, brownies, chocolate chip cookies, mole...  Most times, there is nothing better than eating chocolate.

6.  What smells do you most dislike?

Eraser and number two pencil.  As soon as I smell them I start to sweat.  I’m not ready for the test!  And, as my readers well know, mayonnaise. It smells so…gooey and white.  I know, I know, mayonnaise doesn’t really have much of a smell unless it’s going bad, but in my mind it’s always going bad.

 7.  What smell did you first dislike, but learned to love?

Anchovy.

8.  What mundane smells inspire you?

The smell of blank paper occasionally inspires me to write.  Alas, it more often fills me with dread.

9.  What scent never fails to take you back in time and why?

Peanuts and cotton candy.  When you’re raised in the circus, those smells can’t help but take you back in time.  At least so I imagine. I wasn’t raised in a circus myself.

10.  What scents do you associate with memories of loved ones?

Mothballs.  What is it about grandmothers and mothballs?  Sure, the scent keeps away the moths, but I think it’s really designed to keep away grandchildren.

11.  What fragrance(s) remind you of growing up?

I’m not sure what fragrance reminds me of growing up, but I’ll tell you what fragrance reminds me to grow up—the fragrance of the envelope my utility bill comes in. That one really smacks you in the face.

12.  What fragrance(s) remind you of the places you visited on vacation?

I spent a few summers on the Adriatic coast where the smellscape (if such a word exists) was dominated by a wonderful mixture of wild mint, fennel, and mustard.  I keep trying to recreate the smell with a breath mint, a licorice stick, and a bottle of French’s Mustard—it doesn’t work.

13.  Describe a piece of sensory literature that is very magical for you.

My favorite book of all time, Charlie and the Chocolate Factory, is sensory literature of the most magical kind. There are too many examples of sensory writing in the book to mention, but one that comes to mind right now for some reason is the experimental chewing gum that Violet tries. Remember?—each piece of gum takes her through the flavors of an entire meal, from first course to dessert. Finally, the taste of blueberry pie turns her into a giant and quite convincing, though presumably inedible, blueberry. A brilliant blue image made indelible in the Gene Wilder film.

Notes:
The five volume set of the Secret Series will be available in paperback on October 2, 2012. The books are currently sold individually.

Photograph of "You Know What" perfume mod bottle, "Eau de Mothball", and "Sucker Punch Meter" by Michelle Krell Kydd.

Creative Commons photograph of farmer with plough horses by Ralf Roletschek.

Photo of beans by Toby at Plate Fodder. Edited by Michelle Krell Kydd and licensed under Creative Commons.

Photo of toasted marshmallow by Evan Amos licensed under Creative Commons.

Photo of mustard field from The Organic Center. Rights revert back to the owner.

Fabulous illustration of Charlie and the Chocolate Factory characters by John Martz. Rights revert back to the illustrator.