I think you might discover that there is a lot more to this question than it appears. Wine is, after all, fermented grape juice. But in the conversion of the juice into the wines we love there is a lot happening. Wine is made up of some key elements that are known as components. And it is these components that give it its taste profile, its scent, its color, its age-worthiness and, to my mind, its magic. So lets take a little swim through the liquid together. And like most of the swimming we do we need some water!
The single biggest component of wine is water. This is water from the juice of the grapes, not the tap, and wine is anywhere from 80 – 90% water. Now this water wont hydrate you, because that juice undergoes fermentation in order to be turned into wine, and we know what that means – alcohol.
Alcohol is the second largest component of wine and to find out how much is in there all you have to do is look at the label. What you’ll generally see is anywhere from 10 – 15%, but dessert wines and fortified wines like port go even higher. Alcohol gives the wine depth and mouthfeel. It seems to add weight to the wine that you can both taste and see. When you taste higher alcohol wines there is a noticeable fullness to the sip and sometimes it might even seem a little hot. By the way – Good wine doesn’t need to be highly alcoholic and one criticism I have about some California winemakers is an over-reliance on too much alcohol to give the wines some “punch” or make the them more robust.
You can actually see the alcohol in wine when you swirl it and look at the tears or legs on the side of the glass. Slower moving legs indicates higher alcohol because alcohol is volatile and it evaporates faster that water, resulting in those slower legs but also wafting the aromas up to your nose when you stick it in the glass and take a good whiff. (See Sips Approach to Wine Tasting). And here’s your Sips Warning: Alcohol is intoxicating – don’t over-consume and don’t drink and drive – call Uber or Lyft instead.
Then there are sugars. Sugar in the grapes are the fuel for fermentation. Fermentation is the conversion of those sugars into alcohol by the action of yeast cells. The yeast are like little Pac-men gobbling up the sugar and spitting out alcohol! Wine contains less than 1% sugar. When the sugar is below our ability to taste it then the wine is considered Dry. When there is some sugar we can taste the wine is generally considered Off Dry and this can range considerably. This is known as the Residual Sugar and winemakers specifically make some wines to give us the little hint of sweetness that many folks like in wines like Riesling or Chenin Blanc. Noticeably very sweet wines are typically found as dessert wines and they have marvelous viscosity and beautifully present tastes of honey – like yummy Ice Wine from Canada or the great Sauternes of France.
Acid is key to a wine’s balance. There are a number of acids present in wine but the main ones are tartaric, malic and lactic. We wont get into the chemistry but acidity in wine can give it a little zip, make it taste fresh, add some taste notes like green apple or that buttery quality of chardonnay, and even influence the color. Lighter colored red wines tend to have more acidity than darker purple wines; pale yellow or greenish white wines tend to be more acidic than mellow yellow ones.
And finally we have the fun stuff – the phenolics. These are the compounds that give wine everything from its color and the vibrancy of its taste, to longevity and age-worthiness. For example, these are where the color gets from the grape skins into the wine, or the flavonoid that give white wines from warmer climates a golden glow. Tannin is a phenolic from the skins and seeds giving red wine a noticeable astringent quality and are critical to aging. And vanillin, with its vanilla bean smell, appears from interaction with oak barrel aging.
So What is Wine? It’s water, alcohol, sugar, acid and a bunch of magic beans called phenolics. But most of all…
“Wine is bottled poetry.” Robert Louis Stevenson.