Should you hold a bottle of wine by the punt when pouring?

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
Should you hold a bottle of wine by the punt when pouring?
—Kenneth, via Facebook
Dear Kenneth,
For those who don’t know, the “punt” is the indentation in the bottom of some bottles of wine. Punts originated as a method of ensuring stability and strengthening the structural integrity of blown glass bottles.
These days, improved glass- and bottle-making techniques have made punts unnecessary on that front, but they remain a vestigial feature of most wine bottles. They’re still useful for collecting sediment as wine ages, and a deep punt can add size and weight to bottles for those who consider big, heavy bottles to carry added prestige.
In formal wine service, bottles should be poured with a single hand gripping the lower half of the bottle. Definitely don’t hold the bottle by the neck or shoulders when pouring. Some people find the punt a comfortable place to put their thumbs and hold a bottle of wine a bit like a bowling ball, but this is not a universally accepted part of formal wine service.
Note that I say not “universally.” Some sommeliers are very fond of this technique, and it can add flair to the presentation if you have a strong thumb and can do this with total control. But I believe that in most formal settings, holding the bottle by the punt is frowned upon and not part of standard sommelier training (not all wine bottles even have punts). If you’re serving wine in a restaurant, ask your manager for guidance on the preferred technique.
—Dr. Vinny