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Explainer Science

What Gives Wine Spicy, Peppery Notes?

How a scientific breakthrough uncovered the reason some wines smell of black pepper

Pix Editors By August 5, 2021
photo illustration of pepper spilled into glass of red wine
Photo illustration by Allison Kahler.

Have you ever been able to smell something in a wine, but the person you’re sharing the bottle with insists it isn’t there?

If it’s the smell of pepper you’re talking about, you may both be right.

Introducing rotundone

At the end of last century, Australian researchers were intrigued. Shiraz from some of Australia’s cooler climates were said to smell of black pepper. But why? 

  • There was nothing in the scientific literature on red wine aroma compounds, so the scientists started from scratch.
  • Years went by but they found nothing. 
  • According to a 2008 report in Wine & Vines magazine, the scientists contacted Symrise AG, a German flavor development company with more sophisticated detection equipment.
  • In 2007, eight years after they started, they had the answer.

It was the biggest discovery in red wine chemistry in 30 years.

Making a breakthrough

The pepper smell comes from a chemical called rotundone, pronounced row-tun-done, found in grape skins.

  • It’s a chemical found in concentrations so small that it’s difficult even for chemists to detect.
  • It’s potent: One teaspoon could make an entire Olympic swimming pool smell like the inside of a pepper grinder.
  • Although white pepper and black pepper smell distinctly different, it’s all still rotundone.
  • Wine writer Dan Berger has theorized that its presence can help a wine to age, as it may help block oxidation.

Flavor scientists were soon finding rotundone everywhere, from Grüner Veltliner to Gamay to Italian varieties. Even Cabernet Sauvignon and Pinot Noir can have it at very, very low levels.

Rotundone’s discovery sparked a hunt for other aroma compounds.

Why does this matter?

Knowing about wine aroma compounds can help you learn which styles of wines you might like — and which ones to avoid.

The finding is a major help to anyone studying wine, because once you can spot aromas like rotundone, it can help you identify a wine without any other clues.

Provided you can smell it, of course.

Smell blindness

Many people have what’s called a “specific anosmia.” Also known as “smell blindness,” it means they lack the ability to smell certain compounds. And 20% of people have smell blindness where the pepper character is concerned.

Goodbye rotundone?

Low rainfall brought about by climate change could mean less rotundone accumulation in grapes, which is bad news for those who love its warming spice. But researchers are working hard on irrigation regimes in countries like Australia, to keep the distinctive character of their wines.

If you’d like to test your own sensitivity to rotundone, try one of these.

bottle of Domaine Les Gryphées Cuvée Les Balmes Beaujolais 2019

Domaine Les Gryphées Cuvée Les Balmes Beaujolais 2019 ($22)

Domaine Les Gryphées is named after gryphaea, the fossilized oysters found in the chalky hills of the region and owned by Pierre and Cécile Durdilly, who have been making wine in Moulin-à-Vent since the 1970s. The wine starts with aromas of red and purple flowers that lead into cherries and red plums, light baking spices, and black pepper, with complementary fruit and spice flavors. It’s medium-bodied with smooth tannins. And, at 14% ABV, the wine is on the rich side, so enjoy it with richer fare, like roasted chicken with mashed potatoes and gravy.

bottle of Alzinger Grüner Veltliner Ried Mühlpoint Federspiel Wachau 2019

Alzinger Grüner Veltliner Ried Mühlpoint Federspiel Wachau 2019 ($37)

Leo Alzinger has made wine in the Wachau, Austria, since 1983 and has become renowned for the Riesling and Grüner Veltliner grown in his mountainous vineyards; the “Ried” in the title means single vineyard, and refers to the Mühlpoint vineyard, which lies on a slope. The wines are long-lived; steely and mineral when young, they become rich and vibrant given several years. It has plenty of lime, green apple, and herbal character on both nose and palate, and plenty of the white pepper for which Grüner Veltliner is famous. Pair with a Thai seafood salad or tuna Niçoise salad.

bottle of Domaine Xavier Gérard Côte-Rôtie Northern Rhône 2017

Domaine Xavier Gérard Côte-Rôtie Northern Rhône 2017 ($75)

This spicy Syrah comes from a family estate that produces wines from some of the most beautiful appellations in the northern Rhône Valley, like Condrieu and Côte Rôtie. Xavier Gérard took over the family estate created by his father François in the 1970s. While the wines have always been well regarded, they are beginning to assume cult status. Built for aging, it’s a wine of heft that will need a few hours in the decanter before serving. In the glass, expect black berries, violets, cinnamon, and, of course, classic aromas of cracked black pepper. Serve with slow-roasted lamb crusted with garlic and herbs.