How do you determine whether a wine is” good”?

The first rule of thumb is to drink what you like. If you enjoy it, then it must be good!

However, if you want to gauge the technical quality of wine, there are five major structural components to assess. After you examine those levels, you can determine if and how they balance each other and lead to an intense or expressive wine with complexity on the nose, palate and finish.

Here are the five most important structural components of wine and how to understand them in the glass.

Sweetness

Just because a wine is fruity doesn’t mean it’s sweet.

Sweetness indicates the amount of residual sugar in wine. So, when people say they prefer a “dry wine,” it’s not to say they don’t enjoy fruity wines, just wines without any real sugar content.

There’s no direct correlation between sweetness or dryness and quality. Sure, you would be hard-pressed to find a 100-point White Zinfandel on Wine Enthusiast, but there are plenty of 100-point sweet wines, like Port and Tokaji, that are some of the most sought-after wines in the world.

Acidity

You know that mouthwatering feeling you get when you bite into a fresh pineapple or sip freshly squeezed lemonade? That’s acidity, and it’s one of the most important components of wine.

Derived from grape pulp, acidity accounts for less than 1% of the composition of wine. (Water comprises 80–86%, and alcohol typically 11–16%.) Acidity helps to make cool-climate white wines zippy and refreshing and helps rich reds, like Saint-Estèphe in Bordeaux or Rioja Gran Reserva, to age gracefully for decades.

While acidity will tend to be lower in red grapes than white, without medium to high acidity in a wine, it will appear as flabby or flat and it will be nearly impossible for it to exhibit balance or harmony.

Tannin

A great exercise to understand tannin is to peel the skin off a red grape and eat it by itself. That drying feeling in your mouth that sucks your cheeks in is from the tannin.

Extended maceration, in which winemakers press the grapes with their skins intact, is one way to impart tannins to wine. Since most white wines are produced without skin contact, the vast majority has little to no tannins.

However, tannins can also come from oak aging, so you will notice a bit of tannin in those big, buttery Napa Chardonnays and gloriously complex Sauternes.

Tannins are more prevalent in red wines because there is more skin contact with the juice during fermentation and when the juice is pressed, or when liquid is separated from solids. The more contact the juice has with the skins, and possibly stems, the more the tannins can be detected in a wine.

Without a healthy dose of tannins, it’s very difficult for a wine to improve and evolve over time. Conversely, a wine that is oversaturated with tannins, and that doesn’t possess enough fruit or acidity to balance it out, will feel astringent and come across as particularly bitter on the finish.

Alcohol

The cat’s out of the bag: Wine has alcohol, and it’s a critical component of the body and weight of your pour.

Alcohol is a byproduct of the fermentation process. The more sugar in whatever grapes are fermented, the higher the wine’s potential alcohol. Grapes develop sugar as they ripen, which explains why high-alcohol wines can come from generally warmer regions like Barossa in Australia, Priorat in Spain and many regions in California, while cool-climate white wines from Vinho Verde in Portugal or the Loire Valley in France tend to have lower alcohol levels.

Lower or higher levels of alcohol are not surefire signs of quality in wine, though. There must be a minimum level of around 8% alcohol by volume (abv) for even the lightest of white wines. And, for those big, high-alcohol reds that exceed 15% abv, there should be a hefty dose of fruit, ample tannins and at least moderate acidity to keep everything balanced.

Body

Residual sugar, tannin and alcohol work in tandem with fruit concentration to determine the body or weight of a wine. The denser the fruit and higher the alcohol, the heavier and fuller-bodied a wine will feel on the palate.

A great way to judge body is to think about water and milk. A light-bodied wine like a New Zealand Sauvignon Blanc will have a consistency similar to water, whereas a full-bodied wine like an Argentine Malbec will be closer to heavy cream. The collaborative effort of all these structural components leads you to determine whether you’re drinking a light-, medium- or full-bodied wine.

So, What Makes a ‘Good’ Wine?

Once you have made your assessments of all these structural components, you can then determine how they complement one another. Does the acidity balance out potentially high tannins?

Does the alcohol complement the high fruit concentration, leading to a long and pleasing finish? Does the combination of these components then culminate in an intense, expressive and potentially complex wine?

If the answer to all these questions is yes, you probably have a good, or possibly outstanding, wine on your hands.