Sensory speculations on the Riedel Coca-Cola glass

The wine news is making hay this week with specialty glassware maker Riedel’s newest custom glass shape designed for Coca-Cola. While the process for selecting the glass sounds pretty empirical — a panel tried Coke out of a bunch of prototype glasses and chose the one they liked best — I can’t help but wonder about the sensory chemical logic behind the design. There’s no sense in being pretentious about this: even if Coke is a mass-produced beverage and a cultural and health nightmare, it’s still very sensorily complex (and unquestionably popular).

The glass recapitulates the wide-shouldered hourglass shape of the old-fashioned glass Coke bottle. That’s simple brand congruity: only the shape of the glass opening and the upper bowl affect the glass’s sensory properties in terms of directing aromatics to the nose and affecting how the liquid hits the palate. The dynamics of how Coke behaves in a glass will be wildly different than wine, with the possible exception of a sweet sparkling. Coke has bubbles, which actively convey volatile aromatics into the head space above the glass. It’s extremely high in both sugar and acid (phosphoric, as opposed to tartaric, malic, and lactic in wine) and contains caffeine, none of which should have a significant affect on aroma save insofar as the sugar increases viscosity. How that compares with the viscosity of wine, where alcohol and glycerol (and sometimes sugar) are responsible for viscosity, I’m not sure.

A spokesperson from Riedel says that the top of the glass is the same shape as the Riedel O-series Sauvignon Blanc glass, which immediately sent me on a search for methoxypyrazines and thiols (two prominent characterizers of Sauv Blanc) in Coke.

No joy, and no surprise: methoxypyrazines are responsible for green bell peppery notes, thiols for various tropical fruit and grapefruit-y aromas. It’s been a while since I had Coke, but I’m pretty confident that neither bell pepper nor passionfruit feature prominently in its flavor profile, even if its citrusy notes are easily agreed-upon. The Open Cola Project recipe, which we might reasonably expect to be in the right ballpark, calls for orange, lemon, and lime oils along with cassia (Chinese cinnamon), nutmeg, coriander, and lavender, and a lot of sugar and acid and caramel color.

From a theoretical perspective, then, I’m going to guess that the glass emphasizes Coke’s spritely and refreshing citrus aromatics first and foremost, leaving the sweet caramel/vanilla and spicy notes to bring up the rear. That testers would prefer that effect is congruent with the famous 1980’s and ’90’s Coke vs. Pepsi trials, which showed that Pepsi tended to win out in sip tests — both because it was sweeter and because it has a heavier initial citrus impression — but that Coke had more lasting fans — because it was less sweet, because Pepsi’s citrus tends to fade after the first few sips, and because Coke has a more robust caramel backbone.

On that basis, the glass should either be really good for a rum-and-coke — if you’re using cheap, sweet rum and want to maintain the refreshing balance of the drink against the extra sugar and body — or really bad for a rum-and-coke — if you’re using decent rum and want to play up the sweet/vanilla/barrel aromas.

If I get hold of a glass, I’ll test the theory — this is worth one small exception to my long-standing boycott of Coca-Cola (as well as Pepsi and a number of other food mega-companies) as a response to the company’s massive funding of campaigns against mandatory labeling of GMO-containing foods (and I can’t stand the stuff in any case). But I’d love to know what characteristics the glass brings out, and to play with fresh vs. flat, ice vs. no ice.

What’s next? A gin and tonic glass? A raw milk glass? An orange juice glass? A Pepsi glass? Tea glasses are apparently in the works, but I can only hope that they’ll differentiate oolong from lapsang souchong from pu ehr.