14 of your most embarrassing questions about wine answered with science

You're in a liquor or grocery store, trying to pick out wine with a group of friends when, inevitably, some unexpected member offers up their expert opinion.

Truth be told, there's a whole lot of science behind wine. Genetics, chemistry, microbiology, and even psychology all play a role in everything from how wine is produced, to which bottles we buy and when.

To get a better sense of what goes into making that glass of red or white, in 2016 we chatted with James Harbertson, a Washington State University professor of enology — that's the study of wine. In honor of National Wine Day, here's everything you need to know.

Is cheap wine bad for you?

No way. Last year, rumors of a lawsuit that claimed that cheap wines had high levels of arsenic in it began circulating. One small detail the rumors left out: The lawsuit compared the levels of arsenic in wine to that of drinking water. To have any kind of negative experience as a result of this, you'd most likely have to drink about 2 liters of wine — a little more than 13 servings' worth.

That's an awful lot of wine.

What's the difference between a wine that costs $50 and a wine that costs $500?

The short answer? Not a lot — so long as you're just drinking it.

The price comes from a number of different factors — the maker, the type of grape, how long it's aged, etc. But if you're just looking for a solid bottle of wine, an inexpensive bottle could taste just as good if not better than a thousand-dollar bottle.

If anything, there's a bigger psychological component at play. A study that conducted a blind taste test in which people were given samples of wine found that they did not get any more enjoyment from a more expensive wine compared to a less expensive version. In another study, researchers found that untrained wine tasters actually liked the more expensive wines less than the cheaper ones.

If you're collecting, on the other hand, of course the price tag will make a difference.

What are tannins and what are they doing in my wine?

You know that dry feeling you get in your mouth after a sip of red wine? You can thank tannins, naturally occurring chemicals that are found in wine and other beverages, like black tea.

Tannins give wine its weight — what makes it more milky than watery — so they're integral to all red wines,

Is it bad if I like $3 wine?

I can't deny it: I love spending only $3 on a bottle of Trader Joe's Charles Shaw wine. And

ome studies have shown that knowing that an increased cost correlated with a more pleasant drinking experience, and there might be some corners cut when making bulk wine, but if it appeals to your taste buds stick with them.

How am I supposed to be able to tell if a wine is floral or fruity, and do these adjectives matter?

Wines tend to include a lot of different aromatic notes, which can be really pleasant if you know what you're doing. I, on the other hand, do not.

Harbertson suggested doing the following exercise to sharpen your senses before the next time you try a glass of wine:

Why is there so much emphasis on smelling wine?

Half the fun of drinking wine is the smell. In one glass of wine, there can be any number of fruity, floral, or earthy smells. And that can change depending on how long the wine is left out in the open. A glass of wine can contain thousands of chemical compounds, which are ready to react at any time.

What's the story with yeast in wine?

All those chemical compounds in your wine likely have to do with yeast, a microscopic fungus responsible for digesting sugar and spitting out alcohol. Yeast is added to wine during the fermentation process. Once it's done eating up all the sugar in the bottle, it dies.

Interestingly, as the University of Hawaii's botany department points out, the skin on grapes already contains a fair amount of yeast that could help with fermentation. But since the winemaker doesn't have a lot of influence over what that yeast does, specific strains of yeast are sometimes added to ensure a level of control.

What's a sulfite and what is it doing in my wine?

Sulfites are a compound prevalent in most wines. Together, the sulfur and oxygen in sulfites act as a powerful preservative to keep the wine from oxidizing too quickly, which can change the flavors of the wine for the worse.

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In fact, yeast actually makes some of these sulfites. Harbertson said that different colonies of yeast in wines will sometimes fight each other by creating sulfites that some strains are more sensitive to. Some people are sensitive to sulfites — which are also found in other foods as a preservative — in which case the best thing to do is avoid them.

What does decanting do?

It all has to do with smell and solids. Especially in older wines, chemical reactions in the wine can end up creating solid particles — everything from dead yeast cells to proteins and other organic compounds. Leaving the wine in a decanter for a while can help ensure those fall to the bottom.

Decanting can also help tone down a strongly aromatic wine.

Why do we cork our wine?

Cork, which is made from bark, is a renewable resource, and its ability to form to the shape of a wine bottle is incredibly helpful at storing wine.

But there's a drawback: Occasionally bad cork can get into the wine, something called "cork taint." It's not going to harm you necessarily, but it will make the wine taste a little funky, like moldy cardboard. Some people are fine drinking that wine, but others — like

Do screw tops mean my wine is cheap?

Nope!

Even though the lack of cork has the stigma of cheap wine, countries like New Zealand have been transitioning to the twist-off style in recent years after getting fed up with bad cork. Not only do you avoid cork taint, but it's also ideal for when a corkscrew isn't handy. Harbertson said that the screw-top is just as effective as cork at keeping air out.

Do genetics play a role in what wine you like?

Definitely. Genes influence whether we prefer sweet, bitter, savory, etc. And that can play a big role in our wine selection.

TAS2R38, is thought to be responsible for making some people incredibly sensitive to bitter tastes while others can't get enough. Other taste genes, like the ones for savory tastes, can also play a role in determining whether or not you prefer a certain type of wine.

Why do I sometimes get a headache even if I've had only one glass of wine?

Most often,

Are there any wines I should avoid?

14 of your most embarrassing questions about wine answered with science

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