When I do wine tastings, one of the most frequent comments I hear is, “I don’t like dry wines, especially red wine. It’s too bitter.”
What Causes A Red Wine to Taste Bitter?
Not to be mistaken with dryness (that's a measure of sugar levels in the wine), the bitter component in dry red wines comes from something called tannin. I’ll try not to get too technical, but tannin is a natural plant polyphenol (bio-chemical) that exists, in part, to protect a plant from predators.
In red wine grapes, tannin exists predominantly in the grape skins and the seeds.
To really experience tannins, you can buy some seeded table grapes from your grocery store and remove the little seeds. Eat just the grapes first, then bite into a seed or two.
Yikes! You mouth will pucker, feel fuzzy, and your teeth, sticky. That is tannin. Bitter, green (like an unripe tomato) and astringent. Tannins also exist in tealeaves: If you’ve ever brewed your tea too strong, you’ll get the same result. And when Autumn leaves sit in a puddle of water in your driveway and the water turns brown: Yup, tannin. Just don't drink that, OK?
How They Get There and Why
Tannins get into a wine during crushing and fermentation. A certain portion of the seeds will break and release their bitter oils into the juice. Even more tannins come from extracting color and flavor from the skins. Lastly, the Oak barrels that the wine is stored in have tannins in them. Yes, Oak trees have tannins too!
So why in the world would a winemaker want tannin in their wines? Well, when used in the correct way, tannin actually adds flavor, structure and longevity to a wine. Think of how using bitter chocolate adds depth to a bowl of smokehouse chili or to a molé sauce. A little bit o’ bitter in the right proportions makes a wine feel balanced and savory. It also allows the wine to age for years without degrading too quickly.
In some parts of the world, if a winemaker feels their grapes don’t have enough tannins, he or she may opt to throw in whole grape clusters (with the stems still attached) during the crush. The stems have tannins in them too.
Give Tannins a Chance (and Time)
Tannins, like all organic substances, decompose over time. So, an aging wine sitting in your cellar is basically going through a controlled, graceful decomposition in the bottle. Drinking it at the right time is a matter of finding the window of opportunity where all of the degrading elements in the bottle are in perfect harmony.
A wine that starts out with strong tannins will, over time, soften and lose its astringency. That can take anywhere from a few years, to decades. You can sometimes tell how young or old a wine is by the condition of its tannins. If they’re bitter, green, and astringent tasting, it’s probably a young wine that needs time in the bottle (or, it was not made with great care and the winemakers pressed the grapes too hard). If the tannins are smooth, slightly dusty or even sweet, it’s probably an older, more expensive wine made with great care.
By the way, white wines can also have tannins in them. If the winemaker does not crush his grapes with care (or maybe even does so intentionally) certain white wines, like Sauvignon Blanc from France can have a slight grip to them as well.
Tannins and Food
Scientifically speaking, tannins bind with proteins and can alter their composition. That means wines higher in tannins work really well with red meats and cheeses, beans and other high-protein foods. So a red wine that may be too astringent on its own, might be completely palatable with a nicely charred Hangar steak.
Embrace The Bitter!
So, maybe this will help you to appreciate the aspect of tannin in wine and encourage you to revisit the more challenging dry wines you might otherwise write off. Humans have been perfecting the art of winemaking for millennia now, and tannins are still in there for a reason. See if you can learn to appreciate why!