What makes drinks bubbly? The science is pretty simple: Carbonation is a solution of carbon dioxide gas in liquid water. If kept under pressure, the carbonation is maintained—normally, the bottle or natural spring serves this purpose.
Why it’s tasty is even cooler. When the bottle is opened, the carbon dioxide gas reacts with water to form carbonic acid. This reaction gives the drink a light acidity, but it's often eclipsed by adding stronger acids. Bubbles within the drink also convey aromatic compounds up to the drinker’s nose, thereby creating a heightened perception of flavor. The bubbles rising through liquid in the mouth also create a pleasant, tingly sensation on the tongue.
When confined, the air around the liquid and the solution itself contains the same amount of carbon dioxide. If a bottle is opened or the liquid leaves the spring, the liquid is no longer in a state of equilibrium with its surroundings.
At this point, the liquid contains an excess of CO2 compared to the air around it. To restore equilibrium, the dissolved carbon dioxide will escape into the atmosphere directly through the liquid’s surface or through the bubbles that rise up. When most of the gas is expelled, the solution reaches a new equilibrium—flat.
One of the biggest factors in the rate of dispersal is the glass. Using a wider mouth glass like a coupe increases the surface area of the liquid exposed to air which allows more of the carbonation to escape quickly. On the other hand, a thin champagne flute minimizes the amount of exposed liquid, preserving the carbonation.
Within the glass, bubbles are formed through a process called heterogeneous nucleation. Nucleation means a phase change (liquid to gas) that happens at tiny, pre-existing points, which are the gas pockets. These pockets are formed by imperfections in the glass or by pieces of debris stuck to its insides. Utilizing a scratched, dirty or flawed glass will, therefore, create more bubbles.
Making a Fizz
In nature, carbonation either arises naturally (as seen in some famous natural springs) or through the process of fermentation. Since carbon dioxide and alcohol are both natural products of fermentation, many alcoholic beverages become carbonated in the bottle.
In forced carbonation, carbon dioxide is forcefully dissolved into water with pressure. Most mass-produced sodas and sparkling waters are made this way, but some beers and sparkling wines are as well.
Interestingly, few guidelines for ideal levels of carbonation exist. Sodas tend to be highly carbonated, but champagnes can often be up to 1.5 times stronger.
Hit the Lab
One of the most famous fizzy cocktails is the French 75. Depending on who you believe, this cocktail was originally made with gin or brandy. Either way, it packs as much of a wallop as its namesake, a rapid-firing and extremely accurate WWI cannon.
This beverage was most likely named by a Parisian bartender around 1915. Aside from that, its history is pretty murky. Some origin stories suggest that someone substituted champagne for soda water in a Tom Collins. Other assert that it was created some time in the 19th century when a bored member of the upper class spiked the popular champagne punch.
However it happened, the resulting cocktail most likely existed for decades before it was actually named. As a result, many different recipes and variations on it exist. Try out different styles—swap brandy for gin, serve it over ice, use different sparkling wines, and drink it out of different glasses to experiment with its carbonation.
0.5 oz simple syrup
0.5 oz fresh squeezed lemon juice
1.5 oz gin
Combine all ingredients in a cocktail shaker. Add ice and shake vigorously for 20-25 seconds or until well combined. Strain into a chilled champagne flute and top with one or two ounces of champagne (or the sparkling wine of your choice).