Carbonation (Injected CO2 Sparkling Wine)

Carbonation, also called the bicycle pump method, takes a base wine and injects carbon dioxide into it, the same method used for fizzy canned drinks (Decanter). The Oxford Companion to Wine, published on JancisRobinson.com, describes it as the simple pumping of carbon dioxide into a tank. The OIV's Code defines carbonated wines as special wines produced from wines, so the starting point is wine. Temperature matters: carbon dioxide is more soluble in a well-chilled liquid, and as the temperature goes up the gas becomes less soluble and wants to escape rapidly (Wine Spectator). The OIV Code also lists membrane contactors, a physical technique using hydrophobic membranes, as a way to increase dissolved carbon dioxide to obtain carbonated wines, and says it can replace the use of bubbling devices or venturi-type systems.

• Starting point: a base wine, with carbon dioxide injected into it
• Same basic method as fizzy canned drinks
• Cold liquid holds more dissolved carbon dioxide than warm liquid
• Membrane contactors can replace bubbling devices or venturi-type systems for adding the gas

In fermentation-based sparkling wine the gas is made inside the wine. In the traditional method, yeast and sugar are added to a still base wine sealed in bottle, and the second fermentation produces carbon dioxide that becomes trapped and forms the bubbles. The dead yeast cells form lees, which break down in a process known as autolysis, releasing aromas such as brioche, toast, pastry and cream (WSET). Tank method wines also get their gas from fermentation but spend little or no time ageing on lees, and WSET describes them as having softer bubbles. Carbonation skips the second fermentation: the gas is injected into a base wine. The difference shows in the glass. Decanter says carbonated bubbles are large and disappear quickly, and Wine Spectator's Dr. Vinny notes that a sparkling wine made by an inexpensive, soda-pop style method will probably go flat quickly, while one made by true secondary fermentation will retain its carbonation a bit longer.

• Traditional method: gas from a second fermentation in bottle, then lees ageing and autolysis aromas (WSET)
• Tank method: gas from fermentation, little or no lees ageing, softer bubbles (WSET)
• Carbonation: gas injected into a base wine; bubbles large and quick to disappear (Decanter)
• Serving tip: a well-chilled sparkling wine releases its gas slowly, in a gentle stream of tiny bubbles (Wine Spectator)

Decanter calls carbonation the cheapest method, and the Oxford Companion to Wine calls it the cheapest and least effective method of sparkling winemaking. In the European Union, aerated sparkling wine must be obtained from wine without a protected designation of origin or a protected geographical indication. A lighter category, aerated semi-sparkling wine, covers wines with an excess pressure of 1 to 2.5 bar at 20 °C due to carbon dioxide that has been wholly or partially added. For comparison, WSET notes that tank method wines, whose gas does come from fermentation, are generally more affordable due to faster production and lower labour requirements.

• The cheapest sparkling method (Decanter)
• EU aerated sparkling wine cannot be made from PDO or PGI wine
• EU aerated semi-sparkling wine: 1 to 2.5 bar at 20 °C, gas wholly or partially added
• Tank method wines are generally more affordable due to faster production and lower labour requirements (WSET)

Regulators draw the line at the source of the gas. The OIV's International Code of Oenological Practices defines sparkling wines by an effervescence resulting from the release of carbon dioxide of exclusively endogenous origin, meaning produced within the wine, with an excess pressure of at least 3.5 bars at 20°C. It names two production techniques: secondary fermentation in bottle and secondary fermentation in closed tank. Carbonated wines sit in a separate OIV category, showing physical characteristics analogous to sparkling wines but with carbon dioxide partially or totally of exogenous origin. EU law follows the same logic. Sparkling wine and quality sparkling wine must release carbon dioxide derived exclusively from fermentation, with minimum excess pressures of 3 bar and 3.5 bar respectively. Because consumers are not always aware of how aerated wines are produced, the EU label must state 'obtained by adding carbon dioxide' or 'obtained by adding carbon anhydride'. Method terms are protected too: 'traditional method' and 'classical method' may only describe sparkling wines bearing a PDO (or a third-country geographical indication) or quality sparkling wines that were made sparkling by a second alcoholic fermentation in the bottle, stayed on the lees for at least nine months and were separated from the lees by disgorging. In the United States, federal standards of identity separate 'sparkling grape wine', made effervescent with carbon dioxide resulting solely from fermentation within a closed container, tank or bottle, from 'carbonated grape wine', made effervescent with carbon dioxide other than that resulting solely from secondary fermentation.

• OIV sparkling wine: carbon dioxide of exclusively endogenous origin, at least 3.5 bars at 20°C
• OIV carbonated wine: carbon dioxide partially or totally of exogenous origin
• EU: the 'obtained by adding carbon dioxide' wording is not needed when the language used already indicates that carbon dioxide has been added
• US: carbonated grape wine is Class 3; sparkling grape wine is Class 2

Facts in this article were checked against the regulatory texts and reference pages listed below. Last verified 2026-09-24.

• https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32013R1308
• https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32019R0033
• https://www.oiv.int/node/2172/download/pdf
• https://www.oiv.int/public/medias/7713/en-oiv-code-2021.pdf
• https://www.ecfr.gov/api/renderer/v1/content/enhanced/current/title-27?part=4&section=4.21
• https://www.wsetglobal.com/knowledge-centre/blog/2026/a-guide-to-sparkling-wine-production-methods-and-regional-styles
• https://www.decanter.com/learn/winemaking-the-facts-2-54064/7/
• https://www.jancisrobinson.com/ocw/detail/carbonation
• https://www.winespectator.com/articles/ask-dr-vinny-2879
• https://www.winespectator.com/articles/dr-vinny-s-valentines-day-tips-bubbly-basics-and-beyond-51202