I’ve never actually attended one of the infamous Riedel seminars at which a sleek Riedel representative demonstrates the magic transformative power of their varietal-specific glassware – living in a small town has its limitations – but I can’t say that I see much point. I would go for the sake of curiosity, but we all already know the outcome. Wine smells and therefore tastes better in nice, spacious Riedel glasses than in stingy standard international tasting glasses. Even when the comparisons are a bit more fair – Riesling in a Riesling glass versus Riesling in a Cabernet glass, perchance – it’s hard to trust judgments that come out of a tasting seminar. The power of suggestion (and all of that Riedel marketing) is too seductive. Observing the same issue, plenty of wine bloggers have tried to escape that influence by taking the experiment home to their kitchens or living rooms, with mixed effects.

Georg Riedel presents a tasting seminar in 2010. Photo: Brian Reider

Georg Riedel presents a tasting seminar in 2010. Photo: Brian Reider

But all of these more or less interesting ways of approaching the question of whether and how glass shape influences wine smell and flavor are missing something: the clinical approach of a trained sensory chemist, and preferably one with a well-equipped biochemistry lab at her disposal. The sensory scientist will still approach the question from the point of view of what real live human tasters can observe; in the end, it’s easy to argue that what really matters is not whether a machine can detect a difference, but whether someone with a nose can perceive a difference. So the sensory scientist will still employ the basic sniff test, but will do so more… well… scientifically.

Instead of just asking guinea pigs to describe how a wine smells or tastes in their own, ad hoc terms, the sensory scientist will be more specific on a few different levels. She’ll likely try to tease out different elements of “taste” – different elements of aroma, and possibly also mouthfeel; acidity, sweetness, and bitterness (real tastes as opposed to smells), and intensity. The tasting panel might be a group of one-time volunteers. But if it’s a trained panel, panelists will probably be trained to fit their descriptions into a particular scale, which means that they’ll spend a few hours – sometimes quite a few hours – sniffing and/or tasting (depending on the study) exemplar wines as a group. They’ll learn things like what “floral” smells like for the purpose of this study. Everyone on the tasting panel will start off with their own ideas about “floral” in wine, but they should all end the training time with the same locked-in definition of “floral.” They are, effectually, calibrating their way of describing their perceptions to a common standard.

There have been plenty of such sensory studies investigating the effects – or lack thereof – of glass shape on aroma, but their results have been inconclusive. That’s hardly surprising when you think about how many decisions the sensory scientist needs to make about the experiment, how those decisions influence the study results, and how many other variables need to be held constant to isolate just the effect of glass shape by itself. First, who does the smelling? Random untrained sometimes-wine drinkers? Or enology students who have participated in multiple trained tasting panels? (Studies have been conducted with both, though not at the same time as far as I’ve read). Second, what kind of wine do you use? Not only are different components of wine aromas differently affected by space – something plenty of studies have shown – but wine aromas change at different rates after pouring; one study threw out all of the Chardonnay data because the Chardonnay aromas changed too much between a first and a later sniff. Third, do you let everyone sniff on his own, or do you try to standardize everyone’s sniffing experience? If you’re aiming for standardization, really, how do you ensure that everyone’s sniff is the same? The study with the Chardonnay-related issues used a remarkably complicated contraption consisting of a padded headrest (similar to the cage-like business the optometrist uses to keep your head still), a moveable platform so that differently sized glasses could all be held at the same distance from the smeller’s face, a vortex – a shaking platform often found in molecular biology labs – underneath the glass to mimic swirling, and a blindfold so that the smeller didn’t see any of this.

No matter, some variables can’t be controlled. The biggest: humans. Every taster/sniffer is different. There’s no getting around it: the individual is often one of the biggest sources of variance in a sensory study; in other words, when we see differences between data points that suggest that different conditions in a study (like the use of different wine glasses) might be different, we can explain a lot of that difference by looking at who was doing the tasting that generated that data point.

Still, all of this isn’t to say that we should just throw the idea of performing a study into the glass recycling along with our superlatively specific wine glasses. The results of such studies can be useful and informative; they just won’t be The One Answer for all time. This past year, the superb sensory folk at UC Davis applied themselves to considering what happens in the headspace – the air held above the wine inside a part-full glass – as wine sits for a while in differently shaped glasses. An important question: the air in the headspace is what we sniff when we sniff and most of what our nose contacts when we sip, and we usually let wine rest in glasses for a bit during normal drinking conditions. This study differed from others by letting the wine sit – equilibrate – in the glass for measured amounts of time instead of having sniffers smell immediately or ignoring the time factor. It used trained panelists who we can assume were pretty savvy about wine – students, staff, and faculty of the UC Davis viticulture and enology department – and looked for chemical differences (using solid phase microextraction; really not part of the story here) in addition to applying the sniff test.

The sensory team poured the same Gewürtztraminer into five “glasses”: a Zweisel Bordeaux glass, an IKEA white wine glass, an IKEA red wine glass, a standard INAO tasting glass, and an Erlenmeyer flask. Each of these, after sitting for zero or five or ten minutes, was held up against the upper lip of a blindfolded panelist for twenty-five seconds. Panelists then ranked the strength of the aroma by fruity, floral, chemical, alcohol/hot, and total aroma intensity; no resmells. Generally speaking, the Bordeaux glass and the INAO glass tended to emphasize the fruity and floral elements of the Gewürtztraminer, while the IKEA red wine glass emphasized hot and chemical qualities. The IKEA white wine glass ended up somewhere in the middle, and the Erlenmeyer flask data was tossed out (for sniffing, not for the chemical analysis), because the panelists could tell the difference between the thick, rolled rim of the Erlenmeyer and the thin rim of the wine glasses; they couldn’t distinguish between the feel of the other wine glasses by upper-lip touch alone. Likewise, chemical analysis showed significant differences in the concentration of multiple aromatic molecules in the glass headspace; in other words, glass shape alone caused different aroma compounds to emerge into the air (thereby becoming smellable) in different ways.

An Erlenmeyer flask.  Photo: Creative Commons - Lucasbosch

An Erlenmeyer flask. Photo: Creative Commons – Lucasbosch

Discussing their results, the sensory team was quick to point out that their experimental conditions don’t mimic normal drinking – there was no swirling here – and that they say very little about actual drinking experiences. They do, nevertheless, provide evidence that glass shape changes the ways in which aromatic compounds come up into the headspace of a glass over time, and that we’re capable of smelling at least some of those differences.

Even if the exact same experiment were to be repeated with every glass in the world so that we could make a map of what sensory characteristics each glass emphasized – a splendid idea, now that I think about it – we’d still have plenty of questions to answer. None of the studies I read addressed the tactile element, for one. Common knowledge says that wine tastes better out of a thin-rimmed glass than out of a thick-lipped one, and I agree; nothing is worse than drinking wine out of a coffee mug. And yet, coffee is great out of a coffee mug, and the idea of drinking even iced coffee out of a wine glass isn’t very appealing. And beer is usually served in pretty solid glasses, with which I’ve never thought to have a problem even when I’m drinking serious attention-grabbing beer. Are thin-rimmed vessels always better for tasting everything, excepting when hot temperatures make a little more lip-protection necessary? Or is there something about the sensory properties of wine that call out with especial necessity for thinness? There are probably studies about this question, but it isn’t a factor I see being incorporated into tests of different wine glasses.

The bottom line: Does glass shape matter, absolutely? Yes. Will one glass emphasize certain aromas in a different way than another glass? Yes. Are those differences significant for you, at your dining room table, with your Washington cabernet blend, in your Bordeaux glass versus your zinfandel glass? No study will tell you that save the one you do yourself at your own table.

[Ed.- For a review of one particular new glass designed for a specific varietal, readers might enjoy Riedel Graffigna Malbec Glasses, also posted today.]

11 Responses

  1. Dwight Furrow

    Fascinating study. Thanks for bringing it to our attention. My impression is that coffee and beer do not change as much as wine does in the glass suggesting that the aroma molecules are less volatile. Perhaps that is why there seems to be less fuss about the glass with regard to beer and coffee.

    However, in the beer world there are norms that govern glassware–pilsners get their own glass, Belgian ales are supposed to be drunk from a goblet, etc. And some beer connoisseurs use brandy snifters for drinking aromatic ales.

    I too would love to see a study addressing this.

    • Erika Szymanski

      Dwight, agreed about the beer study. I’ll admit that I haven’t yet dug around for one, but I’ll have to do so. I know, for myself, that I do think different beers taste better out of different glasses — I often pour my more aromatic, higher ABV favorites into bulbous red wine stems — but I don’t know how much that’s the ever-powerful power of suggestion working on me.

  2. Two Shepherds, William Allen

    As always, Davis tries to boil everything about wine down to science, thankfully there are many parts of wine, that will always elude that.
    Thats the magic of this living product.

    Is very easy to quickly notice how much a wine glass changes aroma, which in turn is hardwired to your palate for flavor analysis. I have a huge selection of stemware, and just pouring the same wine, in say, Riedel Bordeaux stem no other type, in 3-4 different sizes, and the wine changes dramatically. The overly large glasses can accentuate alcohol e.g. My massive Riedel Sommelier series glasses, gather dust, they too often don’t accurately reflect a wine, or its best, despite the name and price point.

    Pouring a wine side by side into a Burgundy vs Bordeaux glass, which will suffice for 75% off your wine tastings, is also another common exercise and pronounced differential experience.

    And as you start to delve into…no two people have the same sensory analysis tools. You might detect the phenolic that gives the aroma of strawberry at 50 parts per million, and I might not perceive it, until 250.

    And, btw, Microbrew tastes great, in a thin Riedel (or other) stem 🙂

    Invest in decent stems. But you don’t need to do the Riedel 20 different varietal glasses.

    • Greg


      UC Davis, as an institution of research and higher learning, will without a doubt use science to broaden the understanding of wine. That is very different from “boiling down everything about wine to science.”

      The purpose of the study was to look at how the shape of the glass affects the perception of the wine. The experiment (at least the sensory part) was designed to isolate the individual from the glass and to have the smeller (not taster, unfortunately) have no knowledge of the container. This is not an easy exercise 🙂 When isolated from the glass, it was very difficult for the smellers to find differences between the glasses.

      I agree that changing a wine glass changes the perception of the wine. The effect is small and much smaller when you can’t see, feel, or hear the glass.



      • Erika Szymanski

        Agreed, Greg. The Davis approach can appear overly reductionist at times but, taken in context and with an understanding of what a study is attempting to accomplish, Davis (and other research institutes’) studies are one powerful tool among many.

  3. Tom Kruse

    Different compounds have varying rates of volatility and molecular weight and they also have varying rates of Brownian motion. It stands to reason that some will stay in a glass easier and some will escape easier. I find that a wine glass that is covered and shaken and left for several seconds before uncovering can reveal quite a bit. In general swirling alone causes about three to four times as much surface area to be exposed to the air and the molecules that can break the surface tension and become airborne will reveal themselves much more than not doing anything. Also your “rate” of sniffing can affect how different molecules become “available” to your olfactory nerves.

  4. Blake Gray

    I went to one Riedel seminar for the general public. They compared wine in one of their specifically designed glasses to wine in a plastic cup. The Riedel glass won.

    • lizzytosi@gmai.com

      don’t say me??! 😀 I also had this experience with different shapes of glasses, in Kufstein, with Mr.Riedel in person.
      So, since that moment, when I have to face any wine tasting – international competitions included!!! – I wonder … “what are we talking about??”
      Great post, Erika, as usual!