“Wow, that’s just a little toooo dry for me,” I said recoiling from the bitter, astringent jolt of a young Cabernet Sauvignon. That unpleasant experience, as I was later to learn, had nothing to do with “dryness,” which is the opposite of sweetness. What it was related to was something entirely different. That harsh, mouth-puckering feeling was caused by a high level component in red wines known as “tannins.”

While most of us, I believe, can easily relate to the weight of “body style” and the crispness of “acidity,” things get a tad perplexing when it comes to tannins. But if you’ve ever crunched on a grape seed, chewed the skin of red plum or a portion of banana peel, or more likely, sipped strongly brewed tea, then you’ve experienced the eye-popping reaction to high level tannins. Your mouth feels like it has no moisture, and it’s been lined with scouring pads. Hence, the confusion with dryness.

Tannins are to red wines what acidity is to white wines. They’re a vital, life-giving component that supplies texture, structure and balance. While acidity has been called the “nervous system” of whites, tannins can be called the “backbone” of reds. It allows them to age and develop flavor and aroma nuances far beyond primary “berry” and “plumy.” And just as there are seasoned wine enthusiasts who are “acidity freaks”, so too are there those wine veterans who like the distinct, textural “grip” and strength of character derived from well integrated tannins.

Why mainly reds? The source of tannins is primarily from grape skins, (think crush and the long soak of fermentation), as well as the oak barrels used during the aging process. Tannin levels are also directly related to the type of grape, the duration of skin contact during fermentation, and the age of the wine. Pinot Noir grape skins, for example, yield lower tannins while Cabernet Sauvignons generally impart a more aggressive style. A very short soak on Zinfandel skins will produce that forward, fruit laden White Zinfandel, while a longer infusion will yield the more traditional, muscular Red Zinfandel. And if you store it for several years, those tannins will fall away and you will perceive a wine with a distinctly different taste and bouquet.

 Without an adequate level of tannins, reds would taste one dimensional, flabby and lifeless. With too much, they would taste unbearably sharp and bitter. With the right balance, they are described as “silky.” And just as acidity tolerance levels vary with each person’s palate, so does one’s reaction differ with various tannin levels. Also, much like acidity in white wines, tannins in reds refresh the palate between bites of crusty, grilled meats and thereby, in the context of accompanying food, genuinely fulfills its intended function.

— Tom Barras