Whether it is the sweet taste of ripe grapes or the dry flavour of crisp apples, often the first thought that comes to mind when considering champagne are the bubbles, that sparkling signature of facetiousness. What you might not think about is where champagne comes from and its production. What is really in a bottle of champagne and how did this signature drink come to be?

The term champagne comes from the Latin term campania, which is used to describe the open countryside north of Rome (Robinson, 2006). Champagne gained popularity in the mid-to-late 18th century when workers began to replace breakfast with a glass of brandy or white wine (Phillips, 2000). At this point in time, only a few thousand bottles were produced, many of them breaking due to the pressure inside. Such ‘sparkling wines’, as scientists called them, sparkled because they had been trapped in a bottle before completely fermenting (Robinson, 2006). The goal then became to allow the wine to effervesce without provoking an explosion. In 1838, a professor named André François developed an instrument that was able to accurately measure the sugar content and determine the resulting bottle pressure (Bassett, 2017). As a result, over the 19th century, over 36 million bottles of champagne were produced in France (Phillips, 2000).

Effervescence: gas discharging from liquid in the form of bubbles (Liger-Belair, 2005).

The quality of champagne is typically measured by the size of the bubbles produced in effervescence. Smaller bubbles are preferred over larger ones due to the amount of CO₂ released (Khaireh et al., 2021). This can greatly impact the taste and mouth-feel for the consumer (Khaireh et al., 2021; Liger-Belair, 2005). To determine the amount of CO₂ in a closed bottle of champagne, a ¹³C magnetic resonance spectroscopy (MRS) technique is employed. This method is nondestructive to the bottle or the wine, and it does not intrude upon the contents of the bottle (Liger-Belair, 2005). MRS detected three compounds in champagne, shown in Figure 1.

The ethanols do not exist with dissolved CO₂ due to the pH of champagne, which is approximately 3.2 (Liger-Belair, 2005). Due to this relatively low pH, carbonated species would not coexist with CO₂. When the bottle is uncorked, the liquid quickly attempts to regain equilibrium. For a classic champagne flute of ~0.1 L, approximately 0.6 L of CO₂ bubbles escape from it for the champagne to return to equilibrium (Liger-Belair, 2005).

Each bubble is approximately 500 μm in diameter, indicating that approximately 10 million bubbles escape your champagne once in the flute (Liger-Belair, 2005). Considering that a champagne bottle is approximately 6 atm, or six times more pressurized than the pressure outside (Phillips, 2000), aren’t you glad champagne bottles are thick-walled with deep punts (Figure 2)?

While champagne is certainly an enticing drink for many, it did not come without its problems. Quite literally, the bottles were explosions waiting to happen. The pressure was on for a solution, and due to the fabulous minds of scientists, everyone can enjoy their bubbly with the right amount of bubbles, sparkles, and pop!

Works Cited

Basset, G., 2017., Know-it-all wine: the 50 essential topics, each explained in under a minute. Wellfleet Press.

Khalreh, M. A., Angot, M., Cilindre, C., Liger-Belair, G., 2021. Unveiling carbon dioxide and ethanol diffusion in carbonated water-ethanol mixtures by molecular dynamics simulations. Molecules, 26, 1711. Available at: 10.3390/molecules26061711 [Accessed on 12 November, 2021].

Liger-Belair, G., 2005. The physics and chemistry behind the bubbling properties of champagne and sparkling wines: a state-of-the-art review. Journal of Agricultural and Food Chemistry, 53(8), 2788-2802. Available at: 10.1021/jf048259e [Accessed on 11 November, 2021].

Lytle-Barnett, 2020. The Anatomy of Lytle-Barnett Sparkling Wine Bottles. Available at: https://lytle-barnett.com/blog/PRODUCTION/The-Anatomy-of-Lytle-Barnett-Sparkling-Wine-Bottles [Accessed 20 November, 2021].

Phillips, R., 2000. A Short History of Wine. New York: Ecco.

Robinson, J., 2006. The Oxford Companion to Wine. Oxford; New York: Oxford University Press.