Want to throw a dinner party with the perfect wine pairing? Then start by learning all about terpenes in wine to impress your vino-loving guests! 

Wine is defined more so by its aromas than any other alcoholic drink, and a number of compounds and factors play into why a glass of wine smells the way it does. Factors could include the region where the grapes were grown, the vintage, and esters and lactones within the fruit. The are also terpenes in many types of wine, and these terpenes have a major impact on the nose and overall flavor profile.

Let’s dive into which terpenes are common in wine, and how they impact the overall presentation and experience of the bottle.

But first...Wine 101

If you’re already familiar with this info from your many vineyard trips, then feel free to skip ahead. But if you’re just now diving into the wonderful world of wine, then keep reading.

There are both volatile and non-volatile compounds that affect aroma. During the first few months there are frequent chemical reactions between these compounds. As the wine ages, these reactions still take place--just a lot slower. 

These volatile compounds are found in both the juice and skin of grapes, but will vary depending on the type of grape (Pssst! Terpenes are one of these volatile compounds). 

It’s thought that these volatile compounds evolved as a way to promote procreation. They would attract insects for pollination and birds for dispersal of seeds. 

Through a process called hydrolysis, these volatile compounds change into aromatic forms. That chemical reaction is what enables us to smell all of these compounds and what creates such beautiful and complex wine bouquets. 

There are several key items that contribute to a wine bouquet, and a few of them are listed below...

Esters

These compounds develop during fermentation when acids and alcohol are reacting. This can occur naturally during the aging process, or it can be influenced by the addition of yeast (the particular yeast strain that’s used can have a HUGE influence on aromatics).

As a wine ages, the esters are constantly shifting back and forth from their original acids and alcohols and then back again into esters. That’s one of the reasons why a wines aroma changes over time.

Oak Lactones

You’ll find lactones in both wine and whiskey because, historically, they were both aged in oak barrels. 

When wine is aged in oak barrels, compounds colloquially called oak lactones can be left behind in the wine. Both the species of oak and the varied processes that wine-makers use can affect the amount of lactones in a wine.

According to Wine Folly, the traditional oak used is either European Oak or American oak and the oak lactones can contribute woody, dill, and coconut aromatic notes.

Thiols

These compounds are a double-edged sword. Just the right amount of them will leave you with a fruity smell . However, too much is considered a wine fault and can leave a rotten, garlic scent. 

These sulfur compounds have been used to preserve wine and keep it from going bad. But the warmer a bottle is, the more of that sulfur smell will be released. 

Luckily, if your bottle has an unpleasant rotten-egg aroma you can decant and/or chill it for roughly 15 minutes to lessen that particular scent.

Terpenes

And finally, terpenes! One of the volatile compounds we mentioned before, terpenes can play a major role in the aroma of the wine.

They’re found in the skin and juice of the grape, and the amount of terpenes can vary due to any number of things. It could be the particular variety of grapes, weather and soil conditions, farming techniques, etc. 

Honestly, terpenes are what we came here for. So let’s dive in even further...

What are the common terpenes in wine?

• Geraniol: This terpene gives white wines, in particular, their rose-y aroma. Geraniol is found in bound grapes that have passed through the fermentation process. Some white wine varietals will contain higher levels of this terpene due to factors such as their region, or terroir, and human-controlled factors like the fermentation process.
• Linalool: If you catch a whiff of lavender upon opening up a bottle, odds are there is linalool present in the grape. You may notice this in Chenin Blanc, for instance, as well as varietals of Muscat grapes, which typically have a high content of both geraniol and linalool.
• Citronellol: Citrus-y aroma common in white wines like Riesling, Chenin Blanc, Chardonnay, and Viognier.
• A-terpeniol : Also known as Nerol, you’ll find a-terpeniol most commonly in varietals of Torrontes, Muscadet, Pinot Grigio, and Semillon.

Terpenes in Wine

Experienced wine connoisseurs are quick to point to the three flavor groups that define a wine: These are Earth, Spice, and Fruit/Floral/Herbal. When it comes to terpenes, we’re talking about the latter category.

Terpenes bring the entire trifecta of this group to life in a good bottle of wine. They can complement an herbal, resine-y hit on the front end with a calmer, fruity and citrusy flavor on the back end. 

The impact of terpenes on a particular varietal is determined by how prominently it features in the grape. 

In some types of wine -- full-on Muscat varieties, in particular -- you’ll see free volatile terpene concentrations reaching 6 milligrams per liter. In semi-Muscat and non-Muscat aromatic varieties, the concentration is lower, generally between one and four milligrams per liter. 

Some wines have no measurable terpenic properties, and (in addition to having a duller nose), these wines have zero milligrams per liter and often don’t have the herbal air to them that muscat wines do once you’ve allowed the wine to breathe a bit.

How do terpenes affect a bottle of wine?

When the wine you’re drinking is laden with terpenes, the main thing you’ll notice is the pungent aroma present -- both when you first uncork the bottle and as you swirl the wine in the glass after pouring.

Beyond their pleasant smells, terpenes are known for their positive effects on everything from anti-inflammatory properties to ease in falling asleep. 

You’d have to drink quite a bit of wine to notice these benefits in the short term (with the exception of the whole sleeping thing, perhaps), but feel free to use the terpene-powered perks of wine to justify your stance on that whole “a glass of wine is good for you” argument that pops up in the media every now and then.

In the interim, enjoy the nose on your favorite bottle of wine. The aromas of the terpenes in a particular bottle are most noticeable before they begin to oxidize. Oxidation reduces the pungent aroma of terpenes and in turn cuts back on the distinct nose of a bottle that makes it unique from other, similar types of wine.

Anyone else craving a glass of wine now?

Now that you understand how terpenes impact the aroma of wine, it might be time to start planning your next dinner party. You’ll really impress your friends as you describe the terpenes in wine and the terpenic properties of the bottle on offer. 

If you can find information about the particular grape variety used or the vintage of the bottle, you can get even MORE information on what terpenes may be present in the bottle. 

So, the next time your guest brings over a 1967 Chateau d’Yquem (as any good guest should) and you’re enjoying the aromatic notes of flowers, tropical fruits, butterscotch, vanilla, caramel and oranges, you’ll be able to launch forth with your newly acquired terpene knowledge. 

Sip, smell, and enjoy.

 Summary - 

• Wine has a more complex aroma than taste and there are several different compounds that contribute to its scent.
• Esters, Oak Lactones, Thiols, and Terpenes are just some of the volatile compounds that contribute to a wines overall sensorial experience.
• Some common terpenes found in wine are Geraniol, Linalool, Citronellol, and A-Terpiniol.
• The amount of terpenes a grape produces can vary depending on the particular grape variety, soil and weather conditions, farming practices, etc.