Stop and Smell the Bubbly

Enough of global warming and toxic waste. Today TheGreenGrok breaks out the champagne.

No, we are not celebrating. We are cogitating on carbonation.

Why do we like to drink carbonated beverages? Maybe because on some level they taste better. But have you ever considered the possibility that your perception of taste has more to do with the bubbles than the liquid?

Compared to most animals, our sense of smell is much neglected and atrophied, arguably the one that gets the least respect among the five traditional senses (oh sorry, six senses for some of you out there). Nevertheless, whether we realize it or not, smell is deeply embedded into our everyday experience. As so aptly described in Marcel Proust’s Swan's Way, the sense of smell is probably the one most closely associated with memory, with taste a close second.

Smell and taste, as you probably know, are closely connected. In the first place they are the only two senses that act as chemical sensors — using the olfactory system in one case and taste buds in the other to identify good chemicals and bad chemicals. When it comes to eating and drinking, the taste buds and the nose work in tandem to separate the edible from the inedible, the safe from the poisonous, the delicious from the rank. (See here.) As we all know, an impaired sense of smell, for example when one has a cold, translates into a highly diminished sense of taste.

Popping Open the Point

So what why the focus on champagne? In a paper published last week in the Proceedings of the National Academy of Sciences Gérard Liger-Belaira of France's Reims University, in Champagne-Ardenne, no less, and his co-authors found that the bubbles formed in champagne pick up a subset of chemicals lining the surface of the liquid. They write, rather poetically for a scientific journal, “As champagne or sparkling wine is poured into a glass, the myriad of ascending bubbles collapse and radiate a multitude of tiny droplets above the free surface into the form of very characteristic and refreshing aerosols.”

The authors, going from the poetic to the scientific in a short span, found that many of the chemicals picked up by the bubbles were of “organoleptic interest.” Organoleptic? Now there is a cool word you don’t come by everyday. It simply means, Merriam-Webster tells us, that they are compounds capable of stimulating the sense organs. Such a feature, again in the authors words, “support[s] the idea that rising and collapsing bubbles act as a continuous paternoster lift for aromas in every glass of champagne.”

In other words, part of the reason that champagne tastes so good is what’s in the bubbles. Those little aerosols that stimulate our sense of smell and taste are concentrated in the fizz rising from the liquid. (Sort of explains why flat champagne is not so enjoyable.)

So that’s it — the intoxicating link between bubbly and smell.

Is that sufficient for a post from TheGreenGrok? Maybe not. So ... even though I promised no serious environmental stuff today ...

The Tie-in With Climate

There is a potential link between carbonation and global warming. The carbonation in our drinks is nothing more than carbon dioxide (CO2) dissolved in liquid under high pressure. Release the pressure by opening the bottle, and the CO2 rushes out, erupting into bubbles that send CO2 into the atmosphere where it acts as a heat-trapper.

Could it be that drinking champagne is another non-green, guilt-inducing pleasure? Does our toasting at weddings and our ringing in the New Year end up adding to our carbon footprint with every sip? Not. Generally, the carbonation in alcoholic drinks, generated by yeast fermenting sugars, is derived from plant material that got its carbon from atmospheric CO2 during photosynthesis — so the release of the CO2 in beer and wine is not a net source of CO2.

But what about carbonated drinks like sodas and artificially carbonated beers and sparkling wines? For these drinks, the CO2 is not generated during fermentation but rather is injected into the drink.

Does the release of that CO2 lead to extra global warming? Probably not. Most of the CO2 currently put in sodas and such is apparently captured as a by-product of other industrial processes that burn fossil fuels and would have gotten into the atmosphere anyway. And in any event, the total amount of CO2 added to the atmosphere from our soft drink consumption looks to be quite small.

If you are concerned about drinking and global warming, a much more important issue is the energy used to produce and transport the product from its source to your mouth. Want to do something about it? Drink local, naturally carbonated spirits and more tap water, and don’t forget to smell deeply when you drink the bubbly.