The Real Reason A Wine Tastes ‘Dry’ (or Not)
We hear it all the time, but what are we really talking about when we call a wine “dry”?
From a winemaker’s technical perspective, “dry” means that a wine has little or no residual sugar –virtually all the sugar that nature packed into the grapes was converted to alcohol or CO2 in the fermentation process. But when wine drinkers use the term in casual conversation, they might unwittingly be referring to something else entirely: tannins.
Tannins are naturally occurring chemical compounds in plants whose impact on the palate is readily familiar to any tea drinker who has ever forgotten they had a cuppa brewing, and let it steep too long. That astringent quality, the sense of the mouth being dried out by the beverage – that’s tannins at work, as they interact with proteins in the saliva, literally reducing the lubrication of the mouth.
Tannins in grapes, as the Oxford Companion to Wine explains, “are predominantly in the skins and seeds of each berry and also the stems” – no matter the color of the grape. So why do we only notice tannin in red wines? That’s where winemaking comes into play.
Red wines are generally fermented with the skins, seeds, and sometimes even some stems mixed in with the juice – altogether, this is called the “must” – and in the process, tannins are imparted into the wine. With white grapes, the juice is pressed off from the skins and seeds before fermentation, thus keeping the wine relatively tannin-free.
These practices have developed because red wines can both handle and benefit from tannins. In concert with lush fruit, just the right amount of astringent tannin, along with acidity, can bolster a wine’s complexity. Tannin can also help clarify and preserve wines. But in white wines, tannins would be too harsh, so acidity alone is the great balancing component.
While different grape varieties can come with more or less tannin, the winemaker still has a lot of influence over how tannins play out in a particular wine – and that influence begins well before the grapes are crushed.
Harvesting grapes too early can result in “green” tannins that can be overly harsh. This is a particular point of focus for the protea winemaking team, since the intention with the Red blend is to make a wine that has good structure, but that foremost can be enjoyed early and that has the versatility to go well with a wide range of foods.
Depending on how ripe the tannins are and how they’re fitting in with the rest of the wine, a winemaker can then adjust the fermentation – temperature, length, amount of mixing – to extract more less of the tannin component. Oak barrels can impart their own tannins to wine, as well, so the considerations continue through the maturing process until bottling. In fact, it doesn’t even end there, because tannins continue to evolve in the bottle! Indeed, their ultimate story isn’t told until the bottle is open, poured, tasted and – we hope – enjoyed.