If you’re new to the wine world, you may be unfamiliar with one of the most commonly used terms: tannins. Tannins are essential components of what makes wine special and distinct—what makes wine taste like wine—and understanding and appreciating wine requires knowledge of them.
Tannins are one of the least understood and most difficult aspects of wine to master because they cannot be isolated and smelled or tasted. But you don’t need a chemistry degree to understand what’s going on in that glass of wine. Understanding and recognising tannins will help you get a long way toward becoming a wine connoisseur.
What Are Tannins?
Tannins are substances found primarily in plants, bark, and leaves that give your tongue a drying, rubbing sensation. Wine tannins are derived from grape skins, seeds, stems, and, most importantly, oak barrels.
Tannins are molecules that occur naturally (the technical word for these compounds is polyphenols). These tannins are released when grape skins, seeds, and stems soak in juice. The more tannins they release, the longer they soak.
Where Do Wine Tannins Come From?
The term “tannin” is centuries old and comes from the process of curing leather with plant extracts, which is known as tanning. Some of the same plant extracts that are used in tanning are also used in winemaking.
Plants use tannins to make themselves unappealing to other creatures that might eat them. They exist to deter animals from consuming a plant’s fruit, leaves, or seeds before the plant is fully mature. Tannins are the botanical equivalent of porcupine quills or beaver tails. The presence of tannins is bad news for non-human animals because it means there is less for them to eat, but it is great news for wine lovers.
How Does Climate Affect Tannins?
A warm climate produces hyper-ripe grapes, whereas a cooler climate causes grapes to age more slowly. The difference influences the types of tannins produced.
Shiraz grapes, for example, are abundant in warm Australia and have smooth, lush, rounded tannins.
Meanwhile, cabernet grapes grow more slowly in the cooler climate of Bordeaux, France, producing more subtle tannins.
How Are Tannins Added to Wine?
Tannins are added to wine during the maceration and fermentation processes.
Fermentation is the process by which yeast converts sugar into alcohol. The sugar source in winemaking is fruit juice (typically grape juice). Tannins are extracted during the fermentation process when whole fruits are fermented (with their skin still on). However, not all wines are made by fermenting the entire fruit. White wine, in particular, is typically made from the fermented flesh of grapes rather than their skin. As a result, very few tannins would be produced in the liquid solution as a result of such a fermentation process.
Maceration is the process of steeping fermented wine in a barrel of grape skins. The alcohol in the newly formed wine aids in the extraction of additional tannins from the grape skins and their incorporation into the liquid solution. This process takes place in the presence of heat, but cold maceration is also possible (although that traditionally occurs before fermentation).
7 Ways Tannins Affect Wine
Understanding tannins is more than just understanding how wine is made. Tannins are also intimately linked to the wine-tasting experience. Tannins affect winemaking and wine tasting in the following ways:
- Taste. The majority of liquids are not considered “dry.” Wine, on the other hand, is characterised by dryness, astringency, and bitterness. Tannins are responsible for those distinct sensations; tannins, not acidity, are what distinguishes wine as wine. The more tannins a wine contains, the drier your mouth is after tasting it. Tannins produce the sensation of puckering your lips after drinking red wine.
- Texture. Texture, also known as “mouthfeel,” refers to how the wine feels in your mouth and throat. Tannin is the most important texture contributor. Tannin can have velvety, silky, firm, or astringent properties.
- Structure. When people talk about structure in wine, they’re referring to the overall picture that a wine creates on your palate. And much of the structure is determined by the textural impression created by the tannins in your mouth, though overall harmony between body, tannins, and acidity is also important.
- Quality. Structure and depth are created by ripe, well-judged tannins. An overly tannic finish, on the other hand, will dry out the mouth and leave the consumer thirsty.
- Strength. Many wine enthusiasts believe that a little tannin can go a long way. Allowing wine to breathe means allowing air to dilute tannins, making them smoother and more understated rather than bold or even overwhelming.
- Age. Tannins are preservatives. Winemakers will sometimes overburden a bottle of wine with tannins to make it last longer and have a longer shelf life. Tannins often become more subtle as they age, which is why aged wines are highly sought after—and costly.
- Balance. The ideal wine has balance, with acid, tannin, and fruit all working in unison. An unbalanced wine is one in which one element, such as tannin, acidity, or alcohol, is noticeably higher than the others.
What Are the Pros of Tannins in Wine?
Tannins not only protect the plants from animals, but they also act as a natural antioxidant to protect the wine after the grapes have been harvested and processed. This is one of the reasons why certain red wines, such as Cabernet Sauvignon, age so well.
What Are the Cons of Tannins in Wine?
Even in small doses, tannins can cause headaches in some people. The best way to find out if you’re prone to tannin headaches is to try other tannin-containing substances, such as:
- Dark chocolate
- Apple juice
- Strong black tea
Can You Remove Tannins From Wine?
Yes, tannins in wine can be removed through a process known as fining. Fining a wine is uncommon, except in the following circumstances:
- If a wine is thought to be too astringent—containing too many or too strong tannins—manufacturers can remove the tannins creating these problems.
- If a winemaker believes that a wine is too bitter, they can balance out the body of the wine by removing some tannins while leaving others in.
- If a wine contains an excessive amount of proteins, the winemaker may choose to remove some of the tannins to reduce or prevent cloudiness.
What Wines Don’t Have Tannins?
Most white wines are fermented without their own skins, which results in a much lower tannic content—this is why white wine is less dry than red wine. There are a few exceptions: some white wines may be more tannic if aged in wooden barrels. This is true, for example, of Chardonnay.
While tannins are commonly found in red wines, there are some that are more tannic than others.
What Wines Are High in Tannins?
- Cabernet Sauvignon
- Petit Verdot
- Petite Sirah
What Red Wines Are Low in Tannins?
- German Riesling
- Pinot Noir