What are tannins in wine?
- Naturally occurring compounds
- Affected by maceration time
- Also affected by pressing and oak aging
- More subtle in white wines
- Rarely found in sparkling wines
- Creates an astringent, drying mouthfeel
- Has a distinct texture
- Reacts with proteins
- Changes as wine ages
If you drink wine, then you’ve probably heard someone refer to the drink’s tannins at one point or another. But what are tannins in wine, and why do so many connoisseurs talk about it?
It’s one of the least understood aspects of wine — and certainly one of the more difficult “concepts” to master. But, while you don’t necessarily need to be an expert on the term, knowing the basics of it will help you better understand the wine you’re enjoying.
Read on to learn how to understand and recognize tannins in your wine — it will take you a long way toward wine connoisseurship!
Naturally occurring compounds
Tannins are a group of naturally occurring compounds, and are scientifically known as “plant-derived polyphenols.” These can be found in abundance in various fruits, seeds, leaves, and more — such as oak, tea, cranberry, cacao, and, of course, grapes.
In wine grapes, tannins come from three primary sources: the skin, the pips or seeds, and the stems. They can also come from the wood barrels used in aging (but more on that later).
Some grape varieties have more tannins than others — these make up the dark, full-bodied wines you may be familiar with. Examples include Cabernet Sauvignons like Rosso & Bianco Cabernet Sauvignon; Malbecs like the Kaiken Mai Malbec 2016; Tempranillo such as the Castillo Ygay Gran Reserva Especial 2010. Wines made from other varietals like Pinot Noir and Grenache have much thinner grape skins, so they tend to be less tannic.
Affected by maceration time
How prominent the tannins are in a bottle of wine is partially due to the maceration time, or the amount of time wine spends in contact with its skins during winemaking.
A shorter maceration time means less exposure to the skins, which means there’s less time for tannins to leach into the wine as it ferments. For example, rosé wines, like the Montes Cherub Rose of Syrah, go through a quick maceration process. This results in their light pink color and subtle tannins.
Some winemakers like to keep the grape stems in along with the skins during maceration. This adds more “structure” to the wines (a.k.a., more tannins), and is commonly used to make wines like Shiraz — like the Jim Barry The Lodge Hill Shiraz.
Once the wine has finished fermenting and going through the maceration process, it proceeds to pressing and aging.
When pressed, the wine is separated from any skins or stems. Some winemakers press through several batches at different pressures to extract varying levels of tannins. Those pressed at higher temperatures will be more tannic. Using this technique allows winemakers to achieve consistent wine blends — even across different vintages.
Aside from pressing, some wines also go through an aging process in oak barrels. This will leach tannins from the wood into the freshly fermented wine — so winemakers only do this with wines with sufficient structure, weight, and flavor. This ensures that the wine won’t be overwhelmed by the wood’s tannins.
Good tannin management is key in winemaking — especially in reds, where tannins are more prominent. Done well, winemakers avoid adding harshness to their wines, which often happens when grapes are over-macerated or over-extracted.
More subtle in white wines
While red vinos are what we commonly refer to when we talk about tannins in wine, they’re also present in whites — albeit in a lower concentration.
This is because some white wines go through a short period of maceration. These grapes are crushed and left on their skins for a few hours. They’re then removed right before they start to ferment — which allows the grapes to full flavor (and some tannins) from their skins. This is the case for aromatic grapes, such as Gewürztraminer and Riesling.
Rarely found in sparkling wines
What about sparkling wines? Generally, tannins are avoided in sparkling wines, because the bubbles they have act like little magnifying glasses that highlight each aspect of the wine.
What then happens if sparkling wines do have prominent tannins is that they come across as bitter and extremely dry — which is unpleasant. The bubbles provide enough textural elements that sparkling wines can do without many tannins.
Very, very few sparkling wines with tannins exist — they’re reds like Shiraz or Lambrusco. These wines counteract the bitterness of the tannins with their intrinsic sweetness. The result is a sparkling wine that is a touch dry, with a hint of sugar that takes the edge off.
Creates an astringent, drying mouthfeel
That said, what do tannins actually taste like? If you’ve ever drunk a dark red wine, then you’ve probably experienced an astringent, mouth-coating (almost drying) feel in your mouth from each sip. This is similar to biting into unripe fruits like plums.
If the wine you’re drinking is well made, this taste can be rather pleasant! But, it’s also why choosing the right wine glass and allowing your wine to aerate or “breathe” before drinking is important. Doing so softens the taste of tannins.
Has a distinct texture
It’s a bit difficult to accurately describe the taste of tannins because it comes off more as a texture, rather than a distinct flavor. The texture of tannins is what gives red wines most of their “body.”
It’s why tannins are often described by connoisseurs and winemakers as different textures — you’ve probably seen the words silky, velvety, and plush to describe them.
When a wine has a moderate amount of tannins — noticeable but not too strong — it’s usually described as “grippy.” When a wine is described as “green,” this means its tannins are on the bitter side and may have an unpleasant astringency. Meanwhile, polished, elegant, and smooth are descriptors for wines with very fine-grained tannins that are pleasant to taste.
If you want to try and determine what kind of quality of tannin you’re experiencing in your wine, try to ask yourself these questions as you take a sip.
- Does a dry sensation coat your mouth immediately, or does it creep in?
- Does it seem to dominate the wine, or is it balanced out by other flavors and textures?
- Is it integrated into the profile, or are they prominent and harsh?
Reacts with proteins
Tannins bind and react with proteins. In more specific terms, they precipitate them, which means they separate them.
What this means for wine lovers is that it reacts to human saliva — which is full of protein. This creates a dry sensation when you drink certain wines. This quality of tannins is also why pairing red wines and meats are so good. The tannins in the wine counteract the proteins and fattiness of the meat, creating an almost harmonious flavor.
Changes as wine ages
Tannins are also said to help a wine age — though this isn’t quite true, since plenty of whites age well even without it.
However, tannins do change as a wine matures. As time passes, tannins go through a process called polymerization. In short, this process creates a softer mouthfeel, which means aged wine is less astringent than younger wines. This is why it’s often said that mature wines have “resolved” tannins, which are smooth and soft.
If you’re new to the world of wine, then you may have wondered “what are tannins in wine?” And, with this post, you may now have a better understanding of how this element provides a key characteristic to many wines.