Tannin – Providing Depth and Interest in Red Wines

We are headed into warmer weather when refreshing, chilled whites begin to dominate our picnics and family gatherings [Likely smaller ones as we observe social distancing and keep our groups under 10 people]. So, while the days and nights are still chilly, perhaps it is time to bring out a couple of bottles of red wine before warm weather comes. One of the major reasons those styles of wine are so popular with many is the complexity evidenced in Cabernets, Pinots, and Bordeaux blends. In nearly every bottle, much of the appeal comes from a substance naturally occurring called tannins. Tannins exist in the seeds and skins of red grapes and are extracted during the fermentation process.

What are ‘tannins’ and what do they contribute to wine other than depth in bigger reds?

A non-wine example helps explain its characteristics most easily. Imagine an extraordinarily strong cup of tea. One sip fills your mouth with a dry, slightly astringent sensation. The liquid chemically robs your saliva of its slippery properties. The astringency and ‘puckerness’ are memorable….and offensive. Tannin is what you are imagining. Like the strong tea example, very young, highly tannic red wines are harsh and rather unpleasant. Overly tannic wines – and over-brewed tea – can be quite bitter.

However, given time, patience and appropriate cellaring conditions, big tannins contribute to making good wines great.

Tannins are present in many, although not all, red wines. To make a traditional red wine like Cabernet Sauvignon, grapes are picked and gently crushed.* The pulp, including seeds and skins, is put into large, open vats. The winemaker adds a strain of high-quality wine yeast. The entire concoction is thoroughly mixed and is then called ‘must.’ During the process that follows, nature takes over: color is transferred from the skins to juice, and the conversion of natural grape sugars into alcohol begins. Depending on the variety of grape and the stylistic decisions made by the winemaker, the time of skin contact can last from a few hours to a week or more. Tannin is extracted from the seeds and skins during this initial phase of fermentation. If high-acid grapes are used, tannins are accentuated. Sweetness helps soften the impact of tannins in lighter wines.

Along with alcohol and natural acidity, tannins act as a preservative and help give red wines their long life. [That $1000 bottle of old French Bordeaux was probably, in its youth, so tannic it would have been undrinkable.] It also affects smell and helps to provide a full ‘mouth feel.’ Over time, either in a barrel or in the bottle or both, tannins soften, meld together with the many other components present, and contribute mightily to what experts call ‘complexity.

Different grape varieties contain varying levels of tannin. Cabernet Sauvignon seeds and skins contain many more tannins than those of a lighter variety like Merlot. If you drink either of those wines, imagine how each tastes different from the other. The ‘Cab’ is heavier, has more mouth feel, and is generally more complex. The Merlot is lighter with more fruit ‘up front.’ If you look at the label, the Cab is probably older than the Merlot as often, Cabs are aged for several years before their release to the public.

So, on a cool spring night, if Riesling just does not seem to fit your mood, consider a lovely glass of a great big Cabernet with your grilled steak.

* [Some winemakers practice ‘whole berry’ fermentation, where the entire bunch is put into vats for the preliminary fermentation process. That is fodder for another whole column.]