You ever seen one of those trucks drive? They are bouncing up and down the whole way. But if I even transport a beer in my pocket shit is done
In: Chemistry
Because you open it after shaking it up. If you leave it closed it will renormalize and the gas will dissolve back into the beer
The violent shaking you do with the beer in hand is MUCH more aggressive than the vibrations it will experience in transit. The truck has tires, springs or airbags, the body of the trailer, the pallet that the cases of beer are packed on and the case itself to absorb all of the shocks and bumps of driving down the road. By the time the bump gets to the can, it’s a little buzz, not a big whack.
Also, if a can isn’t opened right after getting shaken up, the carbonation will settle out and blend back in with the beer and be able to escape at a normal speed with the can is actually opened.
When you shake a carbonated drink, the gas tries to get out. If the gas cannot find a way out of the liquid, it will dissolve back into the drink over time.
When drink cans or bottles are closed, there is enough pressure in the can/bottle to prevent the gas from escaping into the air. So if you just wait a while, it will be safe to open again.
When you open a can while the gas is excited, the pressure in the can evens out with the pressure of the air, and now all the gas is able to escape (bringing some liquid with it) causing the fizz that explodes out of the can.
Gas needs two things to remain in solution (simply speaking, it’s likely more complicated scientifically): cold liquid – gas dissolves better in cold liquids than warm – and pressure. The beer in the truck is not cold, but the cans are sealed and pressurized. The pressure prevents the CO2 from escaping into the can’s head space (the small volume of empty space at the top). When the can is shaken, everything is disturbed but the gas has nowhere to go, so it settles back into solution because the can wants to equalize – the head space won’t just fill continually with gas, the beer will take it back until equilibrium is found. When you shake a can and then open it, gas is agitated and actively escaping already, so beer volcanoes out.
Beer is carbonated at a brewery to a higher level than required for the finished product. When the beer is canned, the tops of the cans are dropped on after the beer is injected into the open can. The beer is filled nearly full, and then passes quickly under a small jet of sterile water that causes the beer to foam (“fobbing” – Foam On Beer). The foam ideally pours a little over the sides of the can, or at least reaches over the top of the can. This causes the oxygen/ambient air to be pushed out the top (oxygen is bad for beer). Then the cap is dropped on and sealed. The extra CO2 escapes the beer into the head space, and this is how the can becomes pressurized. If all is done correctly, the beer in the can is at the right level of carbonation after this process, and remains so until you open the can. It’s a balancing act.
Source: am pro brewer.
Edit: not really explained like you’re 5 but I think it’s interesting.
If you took one of those beers right off the truck and opened it, it would explode. It doesn’t matter how hard you shake it. It’s how long after shaking the can is opened.
The foaminess isn’t permanent. When you shake it the carbonation comes out of the liquid and makes foam and pressure. If it then sits still, the gas dissolves back into the liquid and it’s fine.
When you open a beer from your pocket, it only foams because you’re opening it before the gas has a chance to dissolve back into the liquid. If you opened a beer right off of one of those trucks, it would explode foam too. But then the beer from the truck gets to the store and after even a few hours sitting still, the gas all goes back in. If you transport a beer in your pocket and then let it sit for a few hours, that won’t explode either, even though it was shaken in the past.
What do you mean it’s done? If you dropped one or shook it REALLY badly just leave it alone for a few minutes. The CO2 will reabsorb into the liquid as long as the pressure is there.
If it’s just shaken a bit from you walking, that really shouldn’t be enough to alter the flavour enough to matter.
Long story short. It’s all about the pressure inside the can/bottle.
Airride suspension is a helluva thing. My brother drove long-haul for a living and told me he once left a full cup of orange juice in the trailer and drove 300+ miles. When he arrived, the cup was still nearly full.
Your beer has prob sat on a shelf for 3 or 4 or 24 or 48 hours before you open it… I’d bet a “just delivered” , right off the truck might be fairly foamy
Follow-up question:
Why does shaking disturb the equilibrium?
There’s no relevant change in temperature, and the pressure at equilibrium isn’t affected by surface area.
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