Why does champagne bubble?

The effervescent charm of champagne lies in its lively bubbles that dance and rise to the surface, creating an enchanting spectacle. But have you ever wondered why champagne bubbles with such exuberance? In this article, we will unravel the science behind the captivating fizz and explore the factors that contribute to champagne's effervescence. Let us explain how it works:

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  1. Secondary Fermentation:

Champagne owes its effervescence to a unique winemaking process called secondary fermentation. After the initial fermentation, a mixture of yeast and sugar, known as the liqueur de tirage, is added to the base wine. This addition triggers a second fermentation within the bottle, producing carbon dioxide (CO2) as a byproduct.

  1. Trapped Carbon Dioxide:

During secondary fermentation, yeast consumes the added sugar and produces alcohol and CO2. Unlike regular still wines, champagne bottles are sealed with a crown cap or cork, preventing the CO2 from escaping. The carbon dioxide becomes trapped inside the bottle, dissolving into the wine and creating pressure.

  1. Nucleation Sites:

The release of carbon dioxide from the wine occurs when the bottle is opened or poured into a glass. The presence of nucleation sites, which are microscopic imperfections or particles on the glass surface, initiates the bubble formation process. These sites provide a surface for the CO2 to gather and form bubbles.

  1. Surface Tension and Bubble Formation:

Surface tension plays a crucial role in bubble formation. As the carbon dioxide reaches the nucleation site, it creates a tiny bubble due to the surface tension of the wine. The surface tension allows the bubble to maintain its shape and rise toward the surface, defying gravity.

  1. Heightened Pressure and Dissolved Carbon Dioxide:

The pressure inside a champagne bottle is typically around six atmospheres (approximately 90 pounds per square inch). This heightened pressure, resulting from the trapped CO2, enhances the dissolution of carbon dioxide in the wine. The dissolved CO2 remains in the liquid until the bottle is opened or the pressure is released.

  1. Glass Shape and Bubbles:

The shape of the glass can significantly impact the formation and presentation of bubbles. Champagne flutes and tulip-shaped glasses, with their elongated design, help concentrate and guide the upward movement of bubbles, enhancing the visual appeal of the sparkling wine.

  1. Temperature Influence:

Temperature affects the release and perception of bubbles in champagne. Lower temperatures retain more dissolved carbon dioxide, reducing bubble formation and creating a softer effervescence. As the temperature increases, more CO2 is released, resulting in a livelier and more vigorous bubble display.


The captivating effervescence of champagne is the result of a complex interplay between secondary fermentation, trapped carbon dioxide, nucleation sites, surface tension, and pressure. These factors come together to create the mesmerizing bubbles that make champagne a symbol of celebration and luxury. Next time you raise a glass of champagne, take a moment to appreciate the scientific marvel behind those effervescent bubbles that enhance both the visual allure and the sensory experience of this iconic sparkling wine.

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