Carbonation explained: how fizzy should your drink be?
How fizzy a drink should be depends on its style: crisp seltzers and sodas usually carry a lot of carbonation, while juice-forward, creamy or wine-like drinks taste better with a softer bubble. Beverage developers measure fizz in "volumes" of carbon dioxide, and small changes in that number change how a drink tastes, smells and holds up in the can. Here is what volumes mean, how carbonation shapes flavor, and how to choose the right level for your product.
What does "volumes of CO2" mean?
A volume of CO2 is a simple idea. If a drink has one volume of carbonation, it holds an amount of carbon dioxide gas that, measured at a fixed reference temperature and pressure, would take up the same space as the liquid. A drink at three volumes holds three times its own space in gas. More volumes means more fizz.
Most carbonated drinks fall roughly between two and four volumes. Gently sparkling drinks sit at the low end, and sharp seltzers and many sodas sit toward the high end. Your developer and co-packer (the manufacturer who fills your drink) will set a target and a tolerance, then measure it during production with dedicated equipment.
How does carbonation change the taste of a drink?
Carbonation is an ingredient, not just texture. When CO2 dissolves in water, a small part of it forms carbonic acid. That affects flavor in several ways:
- Bite and tingle. The prickly feeling on your tongue comes partly from that acid, not just the bubbles.
- Sharper acidity. Higher carbonation makes a drink taste tarter and drier.
- Lifted aroma. Bubbles carry aroma up out of the glass, which helps unsweetened drinks taste more flavorful.
- Lower perceived sweetness. The bite of CO2 cuts through sugar, so the same drink can taste less sweet at higher carbonation.
- Exaggerated bitterness. Bitter botanicals can feel harsher under a big bubble, which matters for functional sparkling tonics.
How do temperature and packaging affect fizz?
Cold liquid holds CO2 much better than warm liquid, which is why drinks are carbonated and filled cold. A warm can holds the same gas but at higher internal pressure, and when it is opened warm, more of the fizz escapes at once.
Packaging matters too:
- Aluminum cans hold carbonation well and block light and oxygen. They are rated for certain internal pressures, so very high carbonation and hot storage need to be checked against the can spec.
- Glass holds carbonation well but is heavy and breakable.
- PET plastic lets a small amount of CO2 pass through over time, so drinks in PET can lose fizz faster.
- Headspace, the small gap at the top of a package, affects how much gas leaves the liquid after sealing.
Heat processing interacts with all of this. Tunnel pasteurization warms sealed, carbonated cans, which raises pressure inside them, so carbonation targets and processing are planned together.
What is the difference between nitro and CO2?
Nitrogen and carbon dioxide do very different jobs:
- CO2 dissolves readily, forms carbonic acid and creates the sharp, prickly bubbles of soda and seltzer.
- Nitrogen barely dissolves and does not form an acid. It creates tiny bubbles, a creamy, velvety mouthfeel and that cascading look in a glass. That is why nitro cold brew and nitro lattes feel so smooth.
Canned nitro drinks usually rely on a small dose of liquid nitrogen at filling, and some use a widget, a small insert that releases gas when the can opens. Nitrogen also has a quieter job: it pressurizes still drinks in cans so the cans stay rigid on the shelf, even though the drink inside is not sparkling.
How do you choose the right carbonation level for your drink?
Treat carbonation like any other formulation decision and test it:
- Make bench samples at several levels, for example low, medium and high, using the same base.
- Taste them at serving temperature, since that is how customers will drink them.
- Taste after time in the final package, not just fresh from the lab.
- Match the bubble to the brand. A crisp, aggressive fizz says something different from a soft, elegant one. Our guide to flavored sparkling water covers how this ties into differentiation.
How do I start?
If your drink tastes great flat but falls short once carbonated, or you are not sure what level to give your co-packer, we can help you test and lock it in. To talk it through, book a call with Nicolas and the team.