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2 Ways to Keep the Fizz in an Opened Carbonated Soft Drink

Having a soft drink go flat before you are done with it can leave you with a bad taste in your mouth. Literally. Whether you want to save a soda for later or just are a slow drinker, it’s common to wonder if it’s possible to keep the fizz inside longer.

The best way to keep carbonated soft drinks fizzy is to transfer the soda into a bottle with a lid. The second best option is to cover the top of the can to help prevent the carbonation from leaking out. Whichever method you opt for, soda will still usually go flat within 2 to 3 days after opening.

I recommend using silicone stretch lids like these, found on Amazon. I bought some a couple of years ago and now use them all the time. It’s nice to have my soda still fizzy the next day!

The rest of the article will explain how carbonation works in soda and give you tips on how to keep it fizzy longer.

How to Keep the Carbonation Inside

The most important thing is to find a way of closing it back to prevent the gas from escaping. And that’s what fizz is – carbon dioxide. It’s lighter than air, and it will rise above and disappear into the ether.

The best choice would be to transfer the soda into a bottle with a lid, but you can get away with finding something to cover the top of the can.

Luckily, in the past couple of years, several manufacturers have come out with silicone covers designed to fit over aluminum cans. Though most of them are supposed to only keep your drink fizzy while you’re drinking it.

The good news is that I actually found a brand that does an excellent job of keeping the fizz inside. I tested it overnight a couple of times and found that my can of Mountain Dew (or Sprite) were both still reasonably fizzy the next day.

They didn’t quite have the same bite as when the can was first opened, but it was definitely good enough to imbibe. If you want to check it out for yourself, you can pick them up on Amazon. (Please click the link to see the listing)


There actually is another option that works for 2-liter bottles, but I don’t recommend it. It’s a novelty item that is designed to keep the bottle upside down, which means that the gas that keeps the soda fizzy moves up and away from the bottle’s opening. And since it’s away from the opening, it can’t escape, and the fizz stays in the drink.

However, it only works for 2 liters, and they have a cap anyway. So why not just leave the lid on?

Related Is it Safe to Drink Soda Left in a Hot Car?

How Long Will a Can of Soda Stay Carbonated?

As long as the seal holds and the gas is contained within an airtight seal, the soda can stay carbonated indefinitely since it has nowhere to escape.

But if you open the container and close it back again, you’ll keep a good amount of carbonation for the next 2 or 3 days. If the container is stored in the fridge, you could get an extra day of fizz.

The exact time frame depends on the manufacturer and the drink itself. The type of container will be a major factor as well.

Can of Soda and Glass With Soda Next to It With Carbonation Escaping

What It Means if You Open a Can of Soda and It’s Completely Flat

If a can of soda is completely flat when opened, it means that the seal was compromised at some point. There’s also a high chance that the soda has spoiled as well.

Best-before dates don’t mean much with soft drinks as long as they are still bubbly. But if it’s flat on top of “expired,” dump it down the drain.

Which One Stays Carbonated for Longest – Glass Bottles, Plastic Bottles, or Cans?

Soft drinks in cans stay carbonated the longest, while the second place goes to glass bottles. This is in case the containers are still unopened. If they are already opened, plastic bottles win.

Does Squeezing a Soda Bottle Keep Carbonation?

Squeezing a soda bottle to keep it carbonated does not work. In fact, it can actually push the gas (and maybe your drink as well) out.

When you open up the bottle of a soft drink, you will find a rubbery layer inside of the cap. That’s there to create a seal that keeps the carbonation in. Once the seal is broken, even if you screw the cap back on tight, you will still lose some of the gas because the bottle is not closed airtight anymore.

The only thing that you can do is to replace the old cap with a vacuum one.

Some home vacuum sealing systems come with caps that should fit all standard bottles, Or you can splurge and get a good champagne stopper.

Silicone stoppers are cheap and easy to find, but they can be a bit of a mixed bag when it comes to effectiveness.

Can You Add Carbonation to Flat Soda?

Carbonation can be added back to flat soda if you have the right equipment. This can be accomplished with either a siphon or a soda maker. A siphon is more versatile, and you can use it to make whipped cream or a mousse. But, it uses small cartridges that are not refillable, and that can get a bit pricey.

Soda makers are an investment and complete unitaskers, but you can easily re-fill the cartridge at your local gas station.

Related 9 Best Non-Carbonated Alcoholic Drinks When Not Feeling Fizzy.

Is It Ok to Drink Flat Soda?

It is usually ok to drink flat soda, assuming it hasn’t spoiled.

In fact, it may also be healthier for your teeth. Carbonation strips the enamel off of your teeth, just for them to be exposed to the sugary soft drink.

Carbonated liquids can remove stains from a carpet or lift dead skin cells, and they are perfectly capable of lifting tooth enamel as well. So, if you are worried about your teeth, drink your sodas flat or through a straw.

What’s the Difference Between Flat and Stale Soda?

Flat soda only lost the fizz. Stale soda might have gone bad and not be safe to drink. If there’s no fizz and you don’t know how long the soda was open, pour it down the drain.

Since soft drinks are high in sugar, they provide a good environment for microbial and fungal growth. And with a little bit of heat and enough time, sugar can turn into alcohol and, eventually, vinegar.

Final thoughts

The inspiration for this article came from the fact that my wife is always leaving open cans of soda in the fridge. They will sit there for days and then, invariably, not be touched again. However, there is a happy ending.

I bought her a pack of the silicone stretch lids that I mentioned earlier for Christmas, and it instantly solved the problem.

They do look weird, but you get used to them.

Thanks for reading!

For more, check out Top 20 Mixers For Alcoholic Beverages