I visited the International Rose Test Garden in Portland, Oregon, this summer, obsessed with sticking my nose into every multi-layered blossom. I had just finished my Intro Sommelier course and was determined to learn how to distinguish the aroma differences among all the different flower colors. We sometimes describe a wine as smelling of “rose,” but in fact one rose might smell like orange, one like black tea, and yet another like savory herbs. How else was I expected to know “white roses” from “yellow roses” during my next exam? So I began to smell.

The task was, to say the least, stimulating to more than just my nose. The ornate landscaping and careful pruning, the countless color variations and striations, the range of simple to complex petal configurations provided a feast for all the senses. But the fragrances—more fragrances than I’d ever imagined could exist, and from just one type of flower—truly took center stage. The rose is one genus of the plant kingdom, but there are over 100 species, with additional variations and sub-species. Just as Gewürztraminer will boast a different aroma than a Cabernet Sauvignon, each rose species sniffed presented me a new and interesting olfactory experience.

Our system of similes is rather elementary. It may help to have a better—though simplified—understanding how we receive and interpret different aromas, and of what exactly they are composed.

At a basic level, the olfactory system is nearly identical across many animal species. Bees use it, dogs use it, we use it. Aroma compounds are received by olfactory receptor neurons, which send the information to the lower brain for processing. Eventually the higher-functioning brain areas make use of it, and depending on the type of aroma, certain behavioral outcomes may result: pleasure, recognition, mating instinct, avoidance, stress, disgust, and so on.

In the wide variety of roses at the garden, I noted an abundance of fresh fruit (mostly citrus and stone fruit) aromas, plus spice, and floral fragrances. Some of the primary compounds responsible for these aromas are indeed found in wines as well. Non-fruit aromas (vanilla or clove for, example) will develop if the wine is aged in wood, and these aromas will evolve and take on further complexity with aging. However, most fresh fruit and floral aromas in wines occur naturally in the grape or are related to the fermentation process. Four of these fruit/floral-related compounds are responsible for a wide variety of pleasant aromas in many plants, ranging from roses to geraniums, black tea to citrus fruit, and grapes including muscat, riesling, and gewürztraminer. They are citronellol, linalool, d-limonene, and cis-rose oxide. Citronellol, commonly found in insect repellent, bears a lemon-like fragrance, while d-limonene has aromas of lemon or orange. Linalool, also found in many citrus fruits as well as in mint, cinnamon, and lavender, can smell powerfully floral, and is commonly used in perfumes and personal hygiene products. Cis-rose oxide is likely responsible for one of the best gewürz aroma markers, lychee. Not surprisingly, the compound is found in the lychee fruit, gewürztraminer-based wines, and also in—you guessed it—roses.

Usually it is a combination of compounds that becomes interpreted as “lemon” or “lychee.” Bright fruit, warm spice, rose petals, or fragrant herbs are all generally regarded as pleasant aromas, though the odor of a bunch of decaying flowers will motivate one to discard them. Similarly, off-odors in wine—cork taint for example, with its odor of moldy basement—lead us to recoil and pour the wine down the drain. But consider Brettanomyces, yeast responsible for creating in wine a certain barnyard odor. This quality can be perceived as good or bad depending on the personal preference of the smeller.

Thus we see an additional level of complexity to the matter of aroma compounds: our sense of smell, much like our sense of taste, is entirely subjective. Interpreting the aromas of a wine—or a rose for that matter—involves the perception of individual compounds that involve a strong, learned memory of more complex aromas.  It’s an imperfect association, but your brain relates the scents regardless, and thus we smell a plethora of fragrances and odors in each different glass or bloom. Environment, mood, previous experience with an aroma, and myriad other experiential factors ensure that any given smell will always be uniquely perceived.

Next time I sniff a wine and think “rose,” I’ll know to ask myself what exactly I mean. Is it spicy, citrusy, honeyed? White rose or yellow? Is it really “rose,” or does it perhaps smell like another flower altogether? My trip to my neighborhood rose garden taught me about the depth I can find in “simple” aromas, and to ponder the hundreds of compounds that make them smell “just so.”

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[author] [author_image timthumb=’on’]http://palatepress.com/wp-content/uploads/2012/05/ryan-reichert.png[/author_image] [author_info]Having grown up in the midwest, Ryan Reichert followed his passion for wine to the Willamette Valley region of Oregon. Always the explorer seeking to learn more he has travelled around the United States and through France, Spain, and Italy. He holds the Advanced Certificate with Distinction from the Wine & Spirits Education Trust, is a French wine enthusiast, a certified Spanish Wine Educator, and is working towards certification as a sommelier with the Court of Master Sommeliers. Ryan is the creator and author for Northwest Whites, a site dedicated entirely to the white wines of the Pacific Northwest. You can also learn more about Ryan on his personal website. Ryan lives in Portland, OR.[/author_info] [/author]

10 Responses

  1. Official Wine Tasting Site » Smells of Wine and Roses : PALATE PRESS

    […] Published by admin at 3:00 am under Uncategorized I had just finished my Intro Sommelier course and was determined to distinguish the difference in aroma of all the different flower colors. How else was I expected to know “white roses” from “yellow roses” during my next exam? Go here to read the rest: Smells of Wine and Roses : PALATE PRESS […]

  2. Brian

    Very cool article. To be honest I imagine I knew that different roses smell different, yet I have a “base” rose smell that in my mind’s nose, I know.

    This reminds me of a great radio show I heard a few weeks back on NPR, here’s a link if you’re interested: http://www.npr.org/templates/story/story.php?storyId=129475851

    It was discussing some of the science behind olfaction, of course very important to winos.

    Brian Wing

  3. Arthur Z. Przebinda

    I will often find myself writing: “some kind of terpene” in preliminary tasting notes. While it may not be meaningful or useful for consumers to see “chemical compound names in place of common aromatics”, perhaps a strong point should be made that evaluators of wine should be applying this approach to better understand the wine on which they are about to pass judgment.

  4. Melinda

    Loved your article about aromas, flavors and some of the science behind them. You offered some great tips. I can relate to what you’re studying for since I did the same in 2009 and passed Level 1 and 2. Afterwards, I wrote a related post on my blog to share with others how about “Picking Aromas and Flavors Out of the Wine”: http://tinyurl.com/2c7xwjp . I’d love to hear your feedback on it too.

  5. Erika Szymanski

    You raise some excellent points! Like Brian, I too have a mental smell-image filed under “rose,” even if the real thing runs a gamut. This makes me wonder about a blind rose smelling: would a panel be able to correctly identify different flower smells, assigning a “rose” label to the rose smells, when presented with a set of aromas including rose and other flowers, or fruits, or teas? Does anyone know if this has been done? Goodness knows sensory science wasn’t born yesterday…

  6. Ryan Reichert

    @Brian – thank you for the reply. I agree that I’ve got a generic “rose” aroma in my head, though it was remarkable to see how “generic” that really was! Thanks for the NPR link, I’ll check it out.
    @Arthur – you make a great point! Knowing that terpenes are part of the aromatic structure and acknowledging them in sensory analysis would be a step in the right direction I think.
    @Melinda – glad you were able to relate! I’ll check out your article.
    @Erika – thank you. That is an interesting question … and I’m sure people that are into roses like we are wine would likely do a great job. Surely from a rose judging perspective there is a quantitative category for aromas.

  7. scents

    Intriguing plan. I’m suprised I failed to notice this on your large news sites initial. Nicely played!