Photo by Flickr user Evan Wood, Creative Commons
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Science proves that the shape of the glass enhances the flavor or wine.
Photo by Flickr user Evan Wood, Creative Commons
The Plate

When It Comes to Wine Glasses, Size and Shape Matter

A spiffy new camera set-up devised by scientists in Japan indicates that glass shape–just like the wine snobs have been telling us all along–affects the flavor of wine.

In a recent study, Kohji Mitsubayashi and colleagues at the Tokyo Medical and Dental University topped wine-filled glasses with a mesh impregnated with alcohol oxidase, an enzyme that converts alcohols and oxygen into aldehydes and hydrogen peroxide. Also added to the mesh were horseradish peroxide and luminol – the kicky chemical that makes bloodstains glow blue at crime scenes. Together, these produce a color change in response to hydrogen peroxide.

All this chemical interplay enables a camera, peering down at the mesh-covered glass, to map the concentration distribution of ethanol vapor rising from the wine glass’s surface. What the Japanese are doing, in effect, is snapping pictures of a wine’s bouquet.

And why do we care about a wine’s bouquet? A quick lesson: Most wines contain somewhere between 10 and 15 percent ethanol–the spirit-lifting alcohol that makes wine such a welcome addition to parties. It’s not ethanol, however, that gives wine its complex aroma and flavor. In fact, according to food scientist Harold McGee, when it comes to taste and smell, alcohol actually gets in the way.

For one thing, alcohol is sharp, pungent, and irritating to the nose and mouth. Bartenders point out that people generally find less alcoholic drinks to be tastier and more aromatic.

McGee explains that alcohol literally traps aroma: Aroma molecules, due to chemical similarities, tend to cling to alcohol molecules, which means that the higher the alcohol content of a drink, the fewer aroma molecules are released to the drinker’s all-important nose.

For this reason, high-alcohol wines are often described as “hot” and unbalanced because the invasive (though generally desirable) alcohol component overwhelms flavor and aroma. Alcohol also tends to accentuate bitterness and to suppress the fruity and floral notes that make the wine-drinking experience so rich.

One solution to this problem is to add water–which, wrong though it sounds, just may work, as recently explored in Just Add Water on the Kitchn blog.

Another, for those who value every undiluted drop of their ethanol, is to drink wine out of the proper glass.

Given the right temperature and the right glass–say, 55oF (13oC) and a deep-bowled glass of Bordeaux–Japanese camera images show a neat doughnut of ethanol vapor around the wine glass rim and a decreased concentration of alcohol in the glass’s center. That vaporous doughnut and hole represent an ideal intersection of physics, chemistry, and geometry. A sip from such a glass will deliver the maximal dose of flavor and aroma molecules with the least interference from volatile alcohol.

The wrong glass, on the other hand, delivers no such thing. When the researchers tested red wine in a martini glass or in a highball glass, of the sort used for serving Scotch on the rocks, ethanol vapor swarmed messily over the glass’s entire surface, indicating an aroma and flavor swamp-out.

So what does this mean for those of us whose cupboards aren’t stocked with eighteen different types of wine glasses – or who, God forbid, have been known to sip chardonnay out of paper cups?

Pending more results from the Japanese, wine experts do offer a few general rules of thumb, although their opinions vary. Wine glasses with stems are preferable, because this keeps your hand from inadvertently warming up the wine. (Stemless wine tumblers, on the other hand, are a lot less easy to smash.)

Clear glass is better than colored or etched because it allows drinkers to get a good look at their wine. Large bowls generally allow for better aeration of the wine, which in turn releases more aroma and flavor.

And as for those intimidated by the dozen or more types of wine glasses, the Wine Folly blog boils them down to a pair of bare necessities: a set of red wine glasses, which are versatile enough for practically everything, and a set of champagne flutes for anniversaries, birthdays, miscellaneous celebrations, and New Year’s Eve.

And should you be heading out for a picnic, wine out of paper cups may not be technically ideal – but it can taste just fine.