The indentation at the bottom of a wine bottle is called a punt. No clue why it's called that, but its shape made sense in the olden days when bottles were hand-fashioned by glassblowers. But there are some good reasons for keeping the punt, including...
- A thin-walled bottom could easily break
- For sparkling wines, the punt increases the strength of the bottle
- Extra weight at the bottom of the bottle gives the bottle more stability