Many factors effect the actual amount of a standard pour
I fairly often receive what I consider “under pours” when I order a wine by the glass. On a rare occasion, I have even sent the wine back and asked for a standard pour. The Alcohol, Tobacco, Tax and Trade Bureau defines a single serving of wine as 150cc's (5 fluid ounces). Go into any upscale restaurant or shop selling stemware and you’ll usually find a plethora of wine goblets. Not only are there glasses for every grape variety under the sun, but they come in a vast array of shapes and sizes. No wonder even the most ardent wine lover can’t measure accurately a serving of wine.
Researchers from Cornell and Iowa State Universities validated this problem in a recent study. They asked subjects to pour a glass of wine into a variety of different glasses. The amount differences that were actually poured were noticeably different depending upon the size of the glass, as well as the shape, and even the type of wine. Here is what the research unearthed:
- Subjects poured roughly 12% more into a wide glass rather than a standard glass.
- Subjects poured 9% more if the wine was a white versus red wine.
Subjects poured >12% more into a glass that was held in their hand, versus the same glass that was placed on a table.
What’s in a glass? The study showed even the most sophisticated wine drinkers don’t know. In summary, when estimating volume people tend to place a larger emphasis on the glass’s height rather than its width, so wider glasses result in larger pours. Authors of the study also noted that since it is easier to pour into a glass that is being held, that this ease creates over pours.
Next time I order by the glass, I will definitely keep these comments in mind especially for a red wine in a less wide glass that I think is under-poured.