Wine · Explainer

Why does a wine bottle have a hollow base?

The hollow base of a wine bottle is called the punt. It forms when the glass is shaped, makes the base sturdier and lets the bottle stand flat. In sparkling wine this base is deeper: European rules require a carbon dioxide pressure of at least 3.5 bar at 20 degrees Celsius. Champagne bottles are built to withstand 20 bar, about three times the natural pressure.

In brief

The key figures

Name The punt, in French piqûre
What it is Hollow dome in the bottom of the bottle
Function Strengthen the bottom and let the bottle stand flat
Sparkling wine Carbonation pressure of at least 3.5 bar at 20 degrees Celsius
Champagne bottle Designed for 20 bar, about three times the natural pressure
Standard measure 75 centilitres; the EU lays down fixed sizes in Directive 2007/45/EC
Depth Varies by bottle model and by glass manufacturer
Size Wine is filled by volume, not by bottle shape

What is the hollow base of a wine bottle called?

The concave dip in the bottom of a wine bottle is called the punt, in French piqûre.

The punt is formed when the glass is shaped in the mould. The glass is pushed inwards at the bottom, so that the bottle stands on a narrow ring instead of the whole base. That ring stays flat, even if the glass shrinks slightly as it cools.

The dome also gives the base a curved shape. A curved surface distributes force better across the glass than a flat one, and that matters as soon as there is pressure in the bottle.

Why is the base deeper in sparkling wine?

Sparkling wine is under pressure, and a deeply domed base bears that pressure better than a flat base.

The European rules require a carbon dioxide pressure of at least 3.5 bar at 20 degrees Celsius for sparkling wine. That is a lower limit; in a bottle ready for sale the pressure is higher in practice.

Bottles are built with a generous margin. The Comité Champagne reports that champagne bottles are designed to withstand 20 bar, about three times the natural pressure in the bottle. Thicker glass and a deep punt are part of that design.

What does the depth of the bottom depend on?

The depth of the punt belongs to the bottle model a producer chooses and differs per glassmaker.

Bottles for sparkling wine almost always have a deep punt, because they are under pressure. With still wine it varies: some models have a pronounced dimple, others an almost flat base.

The amount of wine does not change as a result. Wine is filled by volume, and the nominal quantity is on the label.

Why does almost every wine bottle say 75 centilitres?

The European Union lays down fixed nominal quantities for prepackaged products, and wine falls under that.

Directive 2007/45/EC of 5 September 2007 lays down those rules. As a result, wine comes onto the market in a limited number of bottle sizes, and 75 centilitres has become the usual size.

The volume is independent of the shape of the base. A bottle with a deep punt and a bottle with a flat base both contain the amount stated on the label.

How do you hold a bottle with a deep punt when pouring?

Many pourers put the thumb in the hollow of the base and lay the fingers along the side of the bottle.

The bottle is then held firmly in one hand and the label stays visible. With a magnum or a larger bottle, two hands work better, because the glass is considerably heavier.

Wij verkopen geen alcohol aan wie jonger is dan achttien jaar. NIX18.

From the shop in Bathmen

Which sparkling wines and champagnes are available in Bathmen?

The shop in Bathmen stocks 122 sparkling wines and champagnes from 56 different brands from 9 countries. Prices range from € 3.49 to € 389.99. The alcohol percentage ranges from 2% to 13.5%.

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Short answer

Short answers to related questions

Does every wine bottle have a concave base?
No. With sparkling wine the punt is almost always deep; with still wine it ranges from a clear dome to an almost flat base.
What is the hollow base called in French?
Piqûre. In Dutch and English the word punt is usually used.
Why is a champagne bottle heavier than an ordinary wine bottle?
The glass is thicker because the bottle has to hold pressure. Champagne bottles are designed to withstand 20 bar.
How much wine is in a bottle with a deep punt?
The quantity stated on the label, usually 75 centilitres. Wine is filled by volume and not by bottle shape.

Further

Read more

All about wine at 't Bockjefilter wine by country, taste and priceAll brands at a glanceWhat is the difference between champagne, cava and prosecco?What does dry wine mean?What is the difference between Old World and New World wine?What do AOC, DOC and DOCG mean on a wine label?All questions about wine

The reasoning

Sources

  1. The Champagne bottle, Comité Champagne (accessed 7 September 2026)
  2. Predicting CO2 Pressure Loss in Aged Traditional-Method Sparkling Wine Bottles for Compliance with European Regulations, Beverages (MDPI), Liger-Belair, Thollin and Cilindre (accessed 7 September 2026)
  3. Richtlijn 2007/45/EG tot vaststelling van regels betreffende nominale hoeveelheden voor voorverpakte producten, European Parliament and Council, via EUR-Lex (accessed 2026-09-07)
  4. International Code of Oenological Practices, Organisation Internationale de la Vigne et du Vin (accessed 2026-09-07)

This page was written and checked by ’t Bockje Bathmen, wine & spirits shop at Brink 2 in Bathmen. Last updated on 14 September 2026.

Verkoop van alcohol onder de 18 jaar is verboden. NIX18.