Tannin Terminology

Even many beginner wine drinkers recognize the term “tannin”, or have heard a wine be described as “tannic”. It might seem as if there’s an infinite amount of wine terminology out there — because there is! — but tannin is an important part of wine and, therefore, one of the most important terms to understand. 

​Understanding tannins and how they work will help you: 

• Choose a bottle of wine that you’ll actually like instead of taking a chance
• ​Understand what to expect from different varietals, in terms of their baseline tannic nature
• ​​Impress your friends 😉 

​Jokes aside, though, most importantly understanding tannin will help you to enjoy and appreciate wine more thoroughly. 

In this article, you’ll learn:

• What Are Tannins

• Where do Tannins in Wine Come From?

• Oak and Hydrolysable Tannins
• Condensed Tannins (Proanthocyanidins)

• 8 High Tannin Red Wine Cultivars

• Lower Tannin Red Wine Cultivars

• Tannin Wine Terminology: 19 Terms You Need to Know

What Are Tannins

Tannins are a group of phenolic compounds found in many species of plants, namely in the bark of trees, wood, leaves, buds, stems, fruits, seeds, and roots. They have gained significant attention in the scientific community over the past several years and are beginning to gain traction in more mainstream media outlets and amongst nutrition-focused groups because of their biological activities (i.e. conferral of health benefits).

​Many foods contain tannins, and a healthy diet generally includes these foods. Some examples are:

Where do Tannins in Wine Come From?

Tannins are one of the reasons and major compounds in red wine leading to its connotation as “healthy”. You may have heard of research suggesting that the compounds in red wine may promote lowered risk of heart disease, reduced risk of stroke, and better management of diabetes, and much of this has been attributed to tannins.

Tannins are present in wines and come from two primary sources:

1. The oak (hydrolysable tannins) that can be imparted during fermentation and aging processes.
2. The grape itself (condensed tannins also known as proanthocyanidins)

Oak and Hydrolysable Tannins

Oak species – used for fermentation and aging – also have the potential to contribute hydrolysable tannins, leaching them into wines during contact. The most commonly used in winemaking are American (Q. Alba), French (Q. petraea or Q. robur) and Slavonian oak (Q. robur), and they impart their influence through barreling, or in some cases, through oak staves and chips. The latter represent a more economical way of introducing oak influences for sensory perception (also known as organoleptic purposes). Oak can be toasted lightly, moderately, or to a heavy degree, which influences the type of concentration of tannins that can be imparted on the wine (1,2).  For instance, heavier toasting releases vanillin, which creates more pronounced vanilla aromas and flavors in wine, and vanillin has also been associated with potential health benefits, including decreasing obesity in animal studies,  cancer prevention,   viral and fungal infections,   and diabetes (3-6).  Other wood species also have the potential to impart hydrolysable tannins in wine, including chestnut, ash and cherry woods, though their use is not typically regulated by winemaking authorities.

Condensed Tannins (Proanthocyanidins)

​Many wines are fermented and aged in stainless steel or concrete tanks, rather than oak barrels. As expected, these wines would not have hydrolysable tannins present as those come from the oak itself; however, the presence of condensed tannins would be anticipated. Condensed tannins, also known as proanthocyanidins, are those which are found in different grape cultivars in different amounts. The condensed tannins are located in the grape skins, seeds and stems and are transferred to the juice in the winemaking process, during maceration and fermentation and through stylistic decisions such as pumpover and pushdown techniques. Extraction can also be maximized under certain time and temperature conditions (7). Noting these factors which can influence the total amount of condensed tannins in finished wine, we did want to share a general list of red wines that tend to pack more tannin in them – and also a short list of those that have much softer tannins.  Most importantly though, it is important to understand that it is these condensed tannin compounds that give wine its affiliation with health, and the field of research around proanthocyanidins and their benefits is rapidly expanding.

8 High Tannin Red Wine Cultivars

Grape cultivars that are naturally and genetically-rich in condensed tannins include:

1. Cabernet Sauvignon
2. Malbec
3. Syrah
4. Sagrantino
5. Nebbiolo
6. Aglianico
7. Monastrell
8. Tannat (the name should be a giveaway)

Lower Tannin Red Wine Cultivars

It’s true that not every wine drinker enjoys the effect of tannins in their wine. They can create a drying, bitter and astringent sensation – that’s nature’s clue that there is something protective going on, a defense signal to predators or to outside attack. Or as we like to look at it, in wine, those sensations are an indication that the wine has a higher concentration of beneficial compounds – and also, that the wine will probably pair very nicely with a juicy, fatty steak, charcuteries and cheeses, or other high-fat foods.

But, in order not to make an omission, we also wanted to share a list of some of the grape cultivars that have the lowest amounts of naturally occurring tannins. These are the types of wines people may seek out when they are looking for something to drink without food (we don’t recommend this), if they’re not as focused on making decisions related to optimizing their drink choice, or if they simply just desire to drink for the purpose of drinking (we also don’t recommend this, because wine is such an intellectual and cultural experience and you cannot fully appreciate it if you don’t get to know the wines a little more.)

​All that said, here is a list of more familiar red wine cultivars with the lowest amount of tannins, though we do want to make one explicit caveat. Just because these cultivars have lower baseline volumes of tannins, viticulturalists and winemakers can make several decisions during harvest and during the winemaking that can influence and increase or even decrease the final amount of tannins, based on their stylistic decisions.

1. Schiava
2. Gamay
3. Pinot Noir
4. Bobal
5. Barbera

Tannin Terminology: 19 Terms You Need to Know

So, there you have it – some science and some practical wine-tasting terminology. Enjoy the tannins in wines and get to know them since they constitute a large part of what gives wine structure, aging-potential, and the potential for improving health.

1. Basalekou, M. et al. Proanthocyanidin content as an astringency estimation tool and maturation index in red and white winemaking technology. Food Chem. 299, 125135 (2019).
2. Laqui‐Estaña, J., López‐Solís, R., Peña‐Neira, Á., Medel‐Marabolí, M. & Obreque‐Slier, E. Wines in contact with oak wood: the impact of the variety (Carménère and Cabernet Sauvignon), format (barrels, chips and staves), and aging time on the phenolic composition. J. Sci. Food Agric. 99, 436–448 (2019).
3. Lim, J. et al. Vanillic acid attenuates obesity via activation of the AMPK pathway and thermogenic factors in vivo and in vitro. doi:10.1096/fj.201700231RR
4. Bezerra, D. P., Soares, A. K. N. & de Sousa, D. P. Overview of the Role of Vanillin on Redox Status and Cancer Development. Oxid. Med. Cell. Longev. 2016, 9734816 (2016).
5. Kim, J. H. et al. A Vanillin Derivative Causes Mitochondrial Dysfunction and Triggers Oxidative Stress in Cryptococcus neoformans. PLoS One 9, e89122 (2014).
6. Guo, J., Han, X., Zhan, J., You, Y. & Huang, W. Vanillin Alleviates High Fat Diet-Induced Obesity and Improves the Gut Microbiota Composition. Front. Microbiol. 9, 2733 (2018).
7. Ćurko, N. et al. Extraction of Proanthocyanidins and Anthocyanins from Grape Skin by Using Ionic Liquids. Food Technol. Biotechnol. 55, 429 (2017).

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