Shaking it increases the amount of surface area between the gas and the air, which lets the CO2 in the liquid reach equilibrium with the gaseous CO2 more quickly. If you shake a bottle that's been sitting sealed for a few days, and let the bubbles rise back to the top before opening it, it will be the same as if you hadn't shaken it.

If there are a lot of bubbles still in the liquid when you open it, those will expand, and increase the surface area for more CO2 to come out of solution, causing the drink to spray everywhere and go flat very quickly.

do u mean when u open it up right after shaking? it should remain fuzzy if u just leave it. has to do with Co2 and equilibrium.

https://www.youtube.com/watch?v=K-Fc08X56R0&t=743s should hlep u understand it a bit more. specifically the part with the bottle of soda.

"Bad" is relative. I love flat cola, I bet many others do too.

Some small pharmacies sell "Coke Syrup" which is literally Coca Cola without the seltzer. It's been used for decades as a medicine to settle your stomach.

Carbonation adds that zing, making it way more enjoyable.

Cause of bubbles pop pop pop

If you only drank coke with no carbonation, you would likely assume it was better than coke with carbonation because it’s what you’re used to. Vice versa

Letting pop go flat means letting all of the carbonic acid turn into water and CO2, and letting all the CO2 leave.

It impacts the taste two ways - you lose the acid, which balances the sugar in the pop, and you lose the fizz, which impacts how it feels in your mouth.

Gasses compress a lot easier than liquids. When the bottle is full the bubbles pop and fill the small amount of space in the top of the bottle, until there is enough pressure to prevent further bubble popping. When the bottle is nearly empty there is a lot more room for the gasses to expand into.

More air in the bottle means more room foe the carbonation to dissipate in to it.

the air in the bottle

The ratio of liquid to air in the bottle at that point is very low. Air compresses; the soft drink doesn't (not in any meaningful measure, as far as this is concerned). So when the bottle is full, only a little bit of carbon dioxide can escape before the pressure is high enough to keep the rest of it in the drink. But as the volume of drink gets lower, more and more escaping CO2 is required to reach that level of pressure. Eventually, you run out of CO2

Before you open the can, there is carbon dioxide gas under pressure on top of the liquid, and it's in equilibrium with carbon dioxide gas dissolved in the liquid.

If you open the can without shaking it, that CO2 just escapes directly into the air, and the gas dissolved in the liquid can only really come out at the existing liquid-gas boundary.

If you shake the can first, you get a ton of bubbles inside the liquid that expand when you release the pressure, and if that wasn't enough, it also provides more surface area for the CO2 dissolved in the liquid to transition into gas, growing the bubbles further.

If you shake the can, and then wait a couple minutes before opening it, those bubbles will rise back to the top, and you can open it without issue.

Shaking the can before it's opened does not significantly change the temperature or pressure.

Flicking the side of the can will help dislodge bubbles there, but it's not relevant to shaking a can, as the shaking will dislodge those bubbles even better than flicking the side of it will. The bubbles form there when changes in temperature make the liquid unable to hold onto as much gas. (if you've opened a can of soda that's hot, and it sprayed everywhere even without shaking it, this is a big reason why)

Bubbles like to form around surface defects or by enlarging existing bubbles. Shaking adds lots of existing bubbles.
Fun fact: mentos have lots of surface defects, which is why mentos make cola fizz up.

Solubility of gasses is affected by temperature. Shaking a fizzy drink increases temperature enough duo to friction to allow gas to come out of solution.

Additionally mixing the drink with thr bit of air in the top adds little bubbles that can act as nucleation spots for more gas to be pulled out of solution.

When you shook it it fizzed up, it expanded but it's contained. When you open it it has somewhere to expand to.

It was already fizzed just couldn't move.

Shaking spreads tiny bubbles all through the liquid. When you open the bottle, the pressure inside drops suddenly, and those bubbles give the dissolved carbon dioxide gas an easy place to escape. The gas rushes out, pushing liquid with it, which is why it fizzes and can overflow. If the drink isn’t shaken, there are fewer bubbles for the gas to collect on, so it escapes more slowly.

It's kind of like letting 10,000 hungry weasels loose in a giant ball pit in the basement, behind a closed door. Of course, when you open the door a bunch of weasels will get loose, but not ALL of them, just the ones who happened to be near the door at the time, rolling around in the ball pit. Every time you open the door, more weasels will get loose in your kitchen, but not all of them at once, because they can't all fit right by the door, they scamper around at random. As more get loose as you keep closing and opening the door, there will be fewer and fewer weasels left, and your soda will be flat, all balls and no more weasels.

If you get them all riled up and open the door, more weasels will get loose at once, and a bunch of balls will probably spill out on the floor too.

There are about 10,000 molecules of water for each molecule of CO2 in soda. And there are two mechanisms that CO2 leaves soda, as individual molecules on the surface, or through visible bubbles that form inside the liquid. Either way, the CO2 molecule has to get past quite a bit of water molecules to either get to the surface, or get to a bubble, where it will be ejected.

It starts to immediately, just takes time... unless you put a mentos in it. Then nucleation points allow all the gas to escape quicker

It is mixed in and compressed. It keeps releasing with each bubble- basically.

I decided to pop this into google and there was a link on physics stack exhange that provided a very in depth explanation - I’ll try to summarize it here, but I’d recommend going there for a deeper explanation.

Basically CO2 leaves because as mentioned by the ccii_geppato, it’s mixed in and compressed and gets slowly released when the pressure decreases upon opening

The gas diffuses though the liquid slowly however, and there is an energy barrier that needs to be overcome in order to form a bubble at all. Often because the can is imperfect it lends itself to forming these bubbles. These are the reasons for the “slowly” part and not all at once.

Edit: I assume if everything was perfect and there was no uneven distribution or imperfections you might just have an open can that sits there with all of the CO2 inside of the soda in a supersaturated state. But the world is imperfect and constantly moving, and an open can is pretty easily disturbed.

Your title implies it's a constant rate of loss.

That won't be the case - hence the wording in the article.

> a loss of some 15–16% of gas may be expected to occur within 8 weeks of bottling.

Not every 8 weeks, just the first 8.

One is too long and technical for anybody to care about, the other simplifies it so that it fits the sub. Idk why everything needs to be so technical with trivial fun facts like this. “Plastic soda loses CO2 because of plastic” “cool learned something today 👍🏼”

My grandparents used to stock 2 liters of soda in the pantry for when we would visit as kids. Loved them dearly but it was always flat by the time we got there.

Can for permeability, glass for flavor.

But what is lost in carbonation is gained in microplastics.

I FRIGGIN KNEW IT.

Give me glass coke every day

>Shelf-life of carbonated drinks in PET is shorter than for products packaged in glass or cans. This is due to the loss of CO2 through container walls. For a typical 2 l PET bottle weighing 43 g, a loss of some 15–16% of gas may be expected to occur within 8 weeks of bottling. For a 250 ml bottle, this loss may be expected to occur within 6 weeks. CO2 loss may be further minimised by incorporating into the PET, at a cost premium, other polymers with better gas retention characteristics. Oxygen ingress can also occur with corresponding deterioration of product.

That's not at all what it says.

You open the container you bought it in, and pour the soda into a container that can be vacuum sealed for longterm storage. Retail soda containers such as cans or bottles cannot store carbonated beverages indefinitely, as the CO2 leaks out slowly within a few years.

What package?

Soda in cans can usually end up leaking. Soda in plastic bottles usually contorts. Glass bottles stay about the same.

Eventually the carbonation will break down.

If you want to keep a can looking sealed make two holes in the bottom. One to let air in and one to let soda out.

With plastic bottles you might be able to try making colored water a similar color as the soda.

Glass bottles can probably last forever. I have a bottle of Dr Pepper from 1969 and it looks about the same, just somewhat lighter in color.

Great question. Have you always lived in the same place? I ask because b/c I notice Coke having different characteristics (carbonation, bite, etc.) in different parts of the US. Perhaps that is intentional, perhaps that is a variation driven by different bottlers or production lines. I also notice a carbonationbdifference between Coke that comes from a can vs. a plastic bottle.

It depends on the residue of what the glass was washed with. That is a serious "release" reason for the CO2.

Yup. Im hour drive from the states. I notice all the drinks from Walmart. Cokecola, Pepsi, 7up all taste different and flat. Soda are still ok at my Canadian Walmart.

They halved the bubbles in each bottle. Shrinkflation......

They may have had one of those nitrogen widgets in it like a can of Guinness. Either that or your brother snuck an alka seltzer in there when you weren’t looking.

i need to know why