Re: Is there an upper limit to how much champagne can explode out of the bottle

I would say that the upper limit would be the entire contents, but the 
likelyhood of all the liquid gushing out of a bottle on its own is pretty 
low.  So, without a single quantitative answer to give you, let me talk a 
little about why the champagne is gushing in the first place.

Gushing, which can happen in any carbonated beverage, is caused by the 
carbon dioxide trying to escape too quickly from the liquid.  Your shaking 
the bottle before opening just makes the problem worse.  A warm temperature 
also encourages gushing because it increases CO2 expansion.  Small 
particles in the beverage or imperfections in the glass will also make the 
gushing worse because they facilitate bubble formation.  But the carbon 
dioxide is by far the driver of this behavior.

CO2 is soluble in water, but not very.  The manufacturers of carbonated 
beverages use chilling and increased pressure to 'encourage' the 
dissolution of higher than normal concentrations in their beverages.  In 
most champagnes, the CO2 is produced naturally and is retained by sealing 
the container.  In any case, the conditions under which the carbonation is 
added and bottled are different than those when you open the bottle back 
up.  The CO2 wants to escape and will form bubbles faster than normal on 
rough surfaces or particulates.  Shaking forces the air/gas usually present 
at the top of the bottle into the rest of the beverage and the CO2 joins up 
with those bubbles for a free ride to the surface.  The quanitity of CO2 
initially in the beverage will affect the force with which it wants to 
escape into the atmosphere.

Rather fuzzy answer to your question but I hope I've helped you understand 
the mechanism behind the behavior you have seen.  Let me know if I can help 
explain this any further.

Kieran