The glass matters, science says so!

We’ve all experienced it, the inevitable barrage of questioning, jovial taunting and understandable confusion upon the expression of revulsion, frustration and dismay toward the choice, or offering, of wine glassware. It’s easy to see how to many this seemingly strange aversion may appear pomp, confusing and unnecessary; however, there’s more to it, stay with me. Anecdotally the majority of us have experienced the enhanced olfactory experience that the ‘right’ glassware can make, but there’s more to this than anecdote. Let’s talk about the science …

I have a family member who loves Prosecco, something I am almost certain you will likely all be able to relate to. The flute is her glass of choice, and from what I see this is an almost universal choice amongst Prosecco drinkers. The reasons for this are broad and varied, I expect tradition, appearance and expectation all play a part. A few weeks ago I initiated a spontaneous experiment of sorts. I poured Prosecco in to her usual glass of choice, the flute, and also in to one of my Gabriel Glas universal tasting glasses. I had her close her eyes, I swirled each glass an equal amount of times, put each to her nose in turn and requested she sniff each. Finally, the eureka moment, she could not believe the stark contrast offered by the different glasses. The Gabriel Glas offered her a Prosecco experience she had not yet been privy to. For the purpose of transparency, my thoughts on the classic flute are that it simply does not provide adequate exposure to oxygen and in essence aromatically ‘shuts’ down sparkling wine.

My friend is a Producer & DJ, he has a captivating and infectious love for music. He has a particular set of headphones; these headphones are incredibly technically able, they are able to adjust the listening experience depending upon the individual listeners hearing. He has selected these headphones because he believes they are most able to best express his music, music which he believes to be deserving of the most suited delivery vehicle. He and I find mutual ground here, his thoughts resonate with me. This is exactly how I feel about wine and glassware, Maximilian Riedel shares this sentiment, he fittingly described his new range of ‘Performance’ glassware as ‘the ultimate loudspeaker for fine wine

A wine glass can be broken down in to 4 core components; the base, the stem, the bowl and the rim, each contributing, arguably not equally, to the overall sensory experience. The base is self-explanatory, it’s purpose is to ensure you’re not left crying over spilled wine. Then we have the stem, the stem serves two distinctive roles; to avoid the temperature of one’s hand providing unwanted warmth to the wine and to keep the hand and all it’s associated aromas as far away as possible from tainting the aromas of the wine in the glass. Next we have the bowl, the bowl forms perhaps the most important component, and relationship between components, that exists in creating fitting glassware. Essentially the bowl is the part of the glass in which the wine settles (in my mind it may also extend to the ‘sides’ of the glass and overall volume) Finally there is the rim, the rim is the point at which the drinkers mouth touches the glass, the rim forms a direct relationship between the wine and the taster.

Variation of style amongst variety-specific glassware

The bowl, the rim, and the relationship between them are of particular importance when discussing the role which glassware plays in the overall sensory experience of wine drinking. Before we talk about why, it may be important to briefly explain wine aroma from a chemical perspective. Wine aroma consists of hundreds of different molecules, including esters, each of these components possesses different degrees of volatility. As wine develops in the glass, a term which in essence explains the relationship between wine and oxygen, these molecules rise and become concentrated in the air above the wine, they become trapped in the glasses ‘head’

The importance of the bowl resides in its primary function where it serves as a mechanism by which the wine is encouraged to interact with the maximum, or most appropriate for the variety, amount of oxygen. The Gabriel Glas universal tasting glass has a shallow bowl, a cone-shaped bottom, this shape means that a smaller amount of wine is able to spread across a much larger diameter, thus exposing a larger surface area to the surrounding oxygen encouraging an enhanced ‘release’ or expression of aroma, RenĂ© Gabriel calls this the bouquet drive. The Gabriel Glas also features a small V-shape curvature at the bottom of the bowl which the makers say creates a ‘push up’ effect which when combined with the glasses conically inward curvature encourages aromas to gather and increases intensity and clarity of expression.

Margaret A. Cliff (2001) found that wine glass shape was able to significantly influence the perceived total intensity of a wine across 18 subjects evaluating a wine against a defined set of characteristics. When it comes to bowl diameter and volume it is the aromatic profile of the wine which will dictate the most fitting size. For a wine like Cabernet Sauvignon which is associated with a more bold, intense and rich aromatic profile a larger bowl diameter and volume would be expected in order to properly expose the wine to an ample amount of oxygen allowing maximum expression of the wines aromas. For a white wine such as Riesling with a more delicate, floral and subtle aroma you may expect a large bowl diameter, smaller volume and more closed opening so as not to expose the wine to too much oxygen thus dissipating the aromas excessively and providing less focus.

Sensory experience is complex and deeply engrained in the human psyche. The feel of a hand-blown glass is undoubtedly a beautiful and heightened sensory experience, one which conveys craftsmanship and art. The incredibly thin, seemingly weightless, lip of a high-quality hand-blown glass allows the drinker to focus more closely on the wine opposed to that of the glass itself. Rim variation varies predominately amongst varietal-specific glassware such as the range offered by Riedel, it was in fact the gently flared lip of their Burgundy Grand Cru glass in 1958 that was thought to be one of the first varietal-specific glasses.

Riedel Burgundy Grand Cru glass showcasing flared lip

To kick the rim topic off I wanted to first tackle a rim-related claim/myth which I have heard more than a handful of times, this being that a flared rim directs the wine toward the tip of the tongue and that where the wine is tasted on the tongue is of particular sensory importance. This segmented-tongue line of thinking echoes throughout the wine community and it’s assessment of tasting. It seems that this line of thinking originates from a misunderstanding of earlier research, there is now broad consensus in modern science that difference in taste perception is minimal across the tongue.

Evidence on the impact of rim variation is limited, the work of Delwiche, Jeannine & Pelchat, Marcia. (2002) does suggest that varietal-specific glassware could have a limited, but subtle, impact upon the olfactory experience of wines. Last year I attended a comparative glassware tasting with Maximilian Riedel, he showcased 4 glasses from his new Performance Tasting range and we tasted the ‘right’ wine in the ‘right’ glass alongside the same wine in the ‘wrong’ glass and albeit anecdotal, and likely influenced greatly by the theatre of the setting, I did record notable difference. I have further noted this sensory difference most drastically in the Zalto Montrachet glass available at 67 Pall Mall, which has a large bowl diameter, extremely wide opening and strikingly short bowl height, this design best suits the elegant, expressive and oaked style of many Montrachet (Chardonnay) wines. It is worth noting that this difference may be less to do with any flaring of the rim and more to do with the relationship between opening size and bowl diameter.

Finally, the relationship between the bowl and the rim (for the purpose of drawing distinction between a flaring or inversion of the rim, specifically the opening size) appears to be perhaps the most important aspect of creating a properly-functioning wine glass (defined by overall impact on intensity of aroma) In her work, Margaret A. Cliff found that where measured by 18 subjects total intensities of a number of wines were highly correlated with the bowl diameter to opening ratio, for the red ( r = 0.99) and white ( r = 0.89) wines. We could deduce from this that the amount of the wine’s surface area exposed (the bowl diameter) to oxygen is of great sensory importance, and in relation to this, dependent on variety, the opening of the rim (the ratio between the two) plays a role in providing a fitting ‘sensory vehicle’ for a particular wine by ‘guiding’ and ‘channeling’ the wines aroma.

So, how do you choose the ‘right’ wine glass? Well, it’s not as complicated as my writing may have made it appear and there is an approach for both the casual wine drinker and the connoisseur. For the casual wine drinker who simply wants to amplify their wine experience at home I would recommend a universal tasting glass from either Gabriel Glas (Standard and Gold Edition) or Zalto. For those who want to take the experience to the next level by purchasing varietal-specific glassware you have a range of options. You could purchase a set of glasses which are intended to suit red wine, white wine and sparkling or you could start with the Riedel Performance Tasting Kit which contains a range of varietal-specific glasses which can be used interchangeably for the aforementioned. Then we have the more expensive side of varietal-specific, Zalto. Zalto offer a range of glassware including their Champagne, Burgundy and Bordeaux glasses which are all fantastic. Personally at home, despite the fact I do own varietal-specific, I tend to use the Gabriel Glas Gold Edition Universal glass, when I go out to a particularly good restaurant (this is where we expect added luxury, right?) I would am left smiling when provided with varietal-specific.

Yale neuroscientist Gordon Shepherd explains in his book Neuroenology: How the Brain Creates the Taste of Wine that counterintuitively taste as a sensory system actually plays a limited role in wine taste and by contrast, smell plays a large role. The importance of sensory experience arguably goes beyond current scientific understanding, whilst we have at our disposal a great deal of psychological understanding, there unquestionably remains a mystery around why a glass can alter our perception of wine. Subtle factors of craftmanship such as the correct weight of the base providing balance in the hand, the length of the stem ensuring a five-finger grip and the mm perfect width of the opening, which go unnoticed but surely contribute to an experience which transcends words, understanding and science, an experience that is able to provide exquisitely-crafted wine with the perfect experiential method of delivery to the drinker.

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