Beer + Liquid Nitrogen: Why Does It Foam & Popcorn?

[YaroslavVB]

1. If you take beer out of the fridge, dip it for 30 seconds in liquid nitrogen, then open it, it will foam up. Skipping the LNO2 cooling stage, it doesn't foam up, why?

2. Pouring a bottle of beer into Dewar of liquid nitrogen, then letting LNO2 evaporate leaves pieces that are shaped like popcorn. Other substances like grain alcohol leave chunks that look like chunks of water ice...why?

 

[mgb_phys]

Difficult to know without more detailed tests and a tasting!
1, Does the beer can have a 'widget' - a little gas cylinder inside to simulate the head of a draught pint? It might be that the thermal shock is breakign that open before the can is opened.

2, If you pour foaming beer into LN2 the foam will freeze into a solid foam. The ice left from gain alcohol is either ice, because the alcohol didn't freese or is just frozen grain alcohol+ water mix dependign on how quickly it cooled.
This used to be a way distilling stronger alochol. You would put eg cider/wine outside in freezing weather, ice would form from the water in the drink leaving a higher concentration of alcohol behind. You discard the ice and repeat.

ps Iassume you mean liquid nitrogen LN2 not liquid nitrogen dioxide LNO2!

 

[Andy Resnick]

Now this is some experimental physics I can really get behind...

For the first question, since the submersion time is less than needed to freeze the beer or make a beer slushy, I would guess that small ice crystals nucleate near the walls of the beer can, forming nucleation sites for gas bubbles upon opening and releasing the pressure.

As for the second, I'll go with mgb_phys.

 

[YaroslavVB]

Thanks, the solid foam explanation makes sense, since boiling corn substance exploding would also be a foam in a sense.

BTW, here's the picture of "solid-state beer"
<img src="http://yaroslavvb.com/pictures/lj/08-03-ln2/-10.jpg">

 

[lewdtenant]

so did you taste the solid state beer or what?