Velvet or Velcro?

If you’ve ever taken a sip of red wine and felt your lips stick to your gums, you know what tannins are. Tannins dry out the mouth by combining with and coagulating the proteins in saliva creating that sticky, drying sensation (too gross?). The intensity varies depending on the quantity and the quality of the tannins. This sensation you experience is astringency.

Astringency is important because it provides structure to wine. Without it, red wine can seem flabby or too much like, well, juice. Moderate levels of astringency allow salinity, bitterness, and sweetness to coexist in harmony. Astringency isn’t a component of taste, but it does change our perception of it. 

Bitterness and astringency are associated with high levels of tannins. In red winemaking, phenolic components are derived from the skin and seed of the grape, grape skins, juice, and pulp which contain friendly tannins, whereas seeds and stems contain the bitter tannins that impart an overly harsh sensation on the palate.

But the grape is not the only source of tannins. Tannins can be extracted from wood during barrel ageing if new-oak barrels are used. Tannin levels are also affected by how the cap is managed during fermentation. The cap is the collection of grape solids that accumulate at the top of the barrel during fermentation. Punching the cap down allows tannins to be extracted gently and dispersed equally within a vessel.

Tannin development begins on the vine. Exposure to sunlight and correct water levels establish how well the berry (aka the grape) extracts tannins. Fluctuating temperatures have the potential to over ripen vines thereby limiting the berry’s ability to acquire tannins.

Tannin levels also affect a wine’s ability to age. A higher level of tannin allows wine to age for a longer period of time. Through oxidation, tannin levels decrease while simultaneously enhancing other characteristics which softens the wine so that it becomes more nuanced.

Tannin levels are higher in grapes that are more sought after, like Cabernet Sauvignon, Merlot, Sangiovese, and Nebbiolo. This is because the potential for ageing is far greater with these varietals. Through oxidation over time, tannin levels decrease. This creates a more complex wine. As red wine ages, tannins and proteins bind which naturally clarifies the wine. This is why aged wines often appear more translucent. 

I’ll stop with the chemistry lesson there. But if you’ve ever been on the fence about tannins, or unsure of what they are, you might check out some of our sturdier reds like the Negro Lorenzo, Langhe Nebbiolo or the Inteus, Rioja Graciano. And if you’re really brave, try the Aglianico di Baal, but make sure you’ve got a nice piece of meat searing on the stove before you take a sip!