The Punt

    The punt is the dimple in the
   bottom center of a wine bottle.

The name probably derives from the word, pontil.   When glass bottles were hand blown, the point where the hot glass was attached to the pontil for rolling and shaping would eventually leave a scar when the pontil was removed.   This mark could make the bottom of the bottle uneven as well as possibly scratching the surface of any table on which the wine bottle was placed.   The glassblower's solution was to hide the pontil's mark by indenting the bottle's bottom.

This pronounced indentation has several
        practical benefits to winemakers.

Sediment will settle in a ring at the bottle's bottom, helping to prevent it from being poured into wine glasses.

It increases the overall strength of the wine bottle, aiding the glass in containing the higher pressures of Champagnes and other sparkling wines.

It makes the bottle less likely to topple over.   A flat bottom with even a small imperfection can be subject to instability.

It allows bottles to be "coupled" when stacked together.   With each neck lodged slightly inside the bottom of the wine bottle of the row in front, the punt helps prevent rolling and breaking, especially during transport.

The punt also aided Champagne producers in securely seating bottles on their filling machines where, after having gone through disgorgement, the bottles would have the sugary dosage added which initiated the bubble-inducing, secondary fermentation.