The fastest way to decarbonate a drink is to pour it into a wide container and stir it vigorously for one to two minutes. This forces dissolved carbon dioxide out of the liquid far more quickly than simply leaving a can or bottle open. Several other techniques work too, and you can combine them for even faster results.
Why Carbonation Leaves (and Why It Stays)
Carbon dioxide stays dissolved in a sealed drink because the container is pressurized. Once you open it, the gas slowly escapes into the air. How fast it escapes depends on three things: how much surface area the liquid has, how many disturbances push the gas out, and the temperature of the drink. A cold, still drink in a narrow bottle will hold its fizz for days. A warm, agitated drink in a wide bowl will go flat in minutes.
NIST solubility data shows that water at freezing temperature holds roughly twice as much dissolved CO2 as water at room temperature. By the time water reaches boiling point, it can hold only about 15% of what it held when ice cold. That relationship is the basis for the warming technique described below.
Stirring and Shaking
Stirring is the simplest and most effective hands-on method. Pour your drink into a large, open glass or bowl and stir briskly with a spoon or whisk for 60 to 90 seconds. Each pass of the spoon creates turbulence that pulls CO2 bubbles out of solution. Industrial beverage labs use the same principle, just with mechanical stirring equipment.
Shaking a sealed bottle also works, but you need to release the pressure carefully. Tighten the cap, shake for a few seconds, then slowly crack the cap to vent the gas. Repeat this shake-and-vent cycle three or four times. Each round removes a layer of dissolved gas. Opening the cap slowly is key, otherwise you’ll spray soda everywhere.
Pouring Between Containers
Pouring the drink back and forth between two glasses or pitchers forces the liquid through open air, creating a large surface area and plenty of turbulence at the same time. Five or six transfers will noticeably flatten most sodas. This technique also works well for sparkling water and beer. You will lose some volume to splashing, so pour over a sink or into wide-mouthed containers.
Warming the Drink
Raising the temperature drives CO2 out because warm liquid physically cannot hold as much dissolved gas as cold liquid. Setting your drink on the counter at room temperature will speed things up compared to leaving it in the fridge. For faster results, pour the drink into a microwave-safe container and heat it gently for 15 to 30 seconds. You are not trying to make it hot, just warm enough to lower the gas solubility. Combine warming with stirring and the drink will go flat in well under a minute.
For comparison, an opened can of soda kept in the fridge will still retain much of its carbonation for two to three days. The same drink left on a warm countertop will be noticeably flatter within a few hours without any effort at all.
Adding Sugar, Salt, or Other Solids
Dropping a pinch of sugar or salt into a carbonated drink triggers a rapid burst of bubbles. The tiny grains create what scientists call nucleation sites: microscopic rough surfaces where dissolved CO2 can gather and form bubbles much faster than it would on smooth glass. This is the same principle behind the famous Mentos-and-soda eruption, just on a smaller scale.
A quarter teaspoon of table sugar or salt stirred into a glass will release a visible rush of fizz. The downside is that you are adding flavor. Sugar makes the drink sweeter, salt makes it saltier. If you do not want to change the taste, stick with stirring or pouring methods instead.
Using a Wide, Shallow Container
Surface area matters. CO2 can only escape where the liquid meets the air. A narrow bottle traps carbonation because very little liquid is exposed at the top. Pouring the same drink into a wide soup bowl or baking dish dramatically increases that contact area, letting gas escape passively much faster. Leave it uncovered for 20 to 30 minutes at room temperature and it will be mostly flat.
Combining Methods for Speed
Each technique on its own works, but the fastest approach stacks several together. Pour the drink into a wide bowl (more surface area), let it sit at room temperature or warm it slightly (lower CO2 solubility), stir vigorously for a minute (mechanical release), and optionally add a small pinch of sugar or salt (nucleation). Done this way, you can flatten most sodas, sparkling waters, or beers in under two minutes.
Why Some People Need Flat Drinks
This is not just a preference question. People recovering from weight loss surgery are typically told to avoid all carbonated beverages for weeks or months afterward, because the gas can cause abdominal discomfort and may stretch the reduced stomach. Johns Hopkins nutrition guidelines for bariatric patients recommend only non-carbonated beverages through at least the first eight weeks post-surgery.
People with acid reflux, irritable bowel syndrome, or general bloating also find that flat versions of their favorite drinks are much easier to tolerate. If someone hands you a sparkling water and you need it still, any of the methods above will get you there quickly without wasting the drink.