If you are handed a plate of sea bass that was pulled off the grill on a summer day, do you grace it with a splash or two of lemon juice? Refreshing, crisp acidity is a burst of excitement in your food and wine. Without acidity, wine would taste flabby and lifeless, as might that lovely sea bass. Acid contributes the tart, zippy, and/or sour flavors you experience in wine. The level can range from low to high, depending on the grape variety, growing conditions, climate, winemaking, and a host of other factors.

​Acid also performs a useful function: it inhibits the growth of bacteria and unsavory microbes. In other words, it acts as a preservative. If you enjoy the classic Italian dish, beef carpaccio, you understand the role of lemon juice or balsamic vinaigrette, aka acids, to protect the raw steak from bacteria and brighten up the flavor.

Low-acid wines taste fuller in the mouth, giving you a soft, round, mellow experience. Wines with high acidity deliver a leaner, more bracing adventure, like taking a vigorous run in cool weather. Wines with high acidity can help improve the wine as it ages, while those with low acidity can cause the wine to lose vibrancy. That is why collectors look for medium to high acidity in the wines they plan to age (along with substantial tannins, alcohol, fruit concentration, and possibly sweetness). A low-acid wine has less protection from contamination so it is customarily drunk young. Sometimes low acid wines, with their sensitivity to oxidation, develop a hazy appearance, though this can be avoided by the winemaker with the addition of sulfur dioxide and/or filtering.

Don’t restrict yourself to either low-acid or high-acid grape varieties; try them all. Many times I have made the mistake of thinking a wine did not have the right resumé only to be surprised and thrilled by the wine’s magnificence. In fact, I made the same mistake when a man who was a few years younger than me (wrong resumé) working at the same firm (double wrong resumé) dropped by my office to “chat” some years ago. That man later turned out to be my husband, Peter.

Once in awhile, you run across a white wine with a surprising mouthfeel or flavor, something that takes you aback and causes you to pay attention. Wines with phenolic bitterness may be among them. Certain grape varieties are known for producing wines that finish with a subtle and pleasant bitterness reminiscent of the sensation you get after eating a young almond or a grapefruit pith. This bitter aspect refreshes and dries out your mouth in preparation for the next drink. Phenolic bitterness causes polarities among drinkers as most people either love it or hate it.

A difference of opinion over phenolic bitterness can occur between happily married couples who have developed a habit of sharing a bottle. Peter and I typically open a bottle with dinner, and the talk sometimes turns to a discussion of the wine that has been poured. I might ask, “What do you think of this Cabernet Franc?” To which he might respond, “Give me a minute,” and take an assessing drink. His answer: “There’s just not much there for me. It just doesn’t do it for me.” It’s a real head-scratcher when your partner does not share your zest for something you find completely scrumptious.

For example, this very morning I got around to tasting a white plum that I had picked up at the farmers market on Sunday. It was so delicious that I felt I had to share it with Peter as part of our marital contract. I cut off a generous portion of the plum with my Japanese pairing knife and offered it to him as though I was the Eve to his Adam. Peter took a bite. To my surprise, his face took on a pained expression and he said, “It’s too sour!” To which I responded, “The tartness is the best part!” I understand intellectually that we are each entitled to our own opinion of what we like and don’t like, so I refrained from explaining that the tartness of the plum was balanced by the fruit’s sweetness and flavor elements. I took back from Peter what was left and consumed the balance of the plums, guilt-free.

Tannins, to me, are the absolute magic of red wine. They contribute longevity, color, flavor, body and overall textural richness. While I adore tannins, I am simultaneously and confusingly captivated by grape varieties that are known to be low in tannins, such as Grenache, Frappato and Gamay. Just when I think, “Ah, ha! I have finally discovered my Holy Grail of wine characteristics,” plenty of opposite examples have me re-thinking my earnest declarations.

​This leads me to believe that there are no hard-and-fast rules about what makes a wine great. Maybe instead of seeing a bottle of wine as possessing specific attributes that you either chase or run away from, it is more open-minded and adult to view each bottle as an individual whose secrets are yet to be revealed. But I digress, so let us explore the world of tannins and why they are a subject of fascination and delight for drinkers, scientists, and industry insiders.

Tannins provide structure to a wine, just as your skeleton supports your body. Without tannins, red wine would be cloyingly sweet. That is why tannins are one important element of a wine’s balance, along with acidity, fruit concentration, sweetness, alcohol, and texture. You eat and drink tannins as a matter of course because they are present in coffee, tea, dark chocolate, walnuts, cranberries and other plant-based foods and beverages. Oak can also contribute tannins to a wine, especially new oak. Producers sometimes use additives such as oak powder to increase the perception of tannins; this practice is associated with large-scale, low-end wines. Seriously, can you see yourself drinking anything that contains oak powder?

Tannins are responsible for the astringent, mouth-puckering sensation of dryness you get in the mouth when drinking wine. When a red wine with firm tannins enters your mouth, it binds to the proteins in your saliva and washes much of the saliva away, leaving your mouth with a feeling of dryness and astringency, even bitterness. To determine whether a wine is high or low in tannins (or something in-between), pause to consider how dry your mouth feels during and after a drink. The dryer your mouth feels, the more tannic the wine. When you drink a delicious wine that is generous with tannins, even while the wine is still in your mouth and yet to be swallowed, why hurry? Experience wine's aromas, flavors and sensations. Much of wine tasting is thoughtfully paying attention to what is in the glass and your mouth. Drink plenty of water between sips to help your body hydrate and to produce more lubricating saliva. Pace yourself.