Yeast Explosion Facts

Hi Matthew, Ummm... Yes and no. I have no idea what 2l plastic bottles are meant to hold pressure wise, but I doubt it's 90 PSIG and that is the maximum pressure a sparkling wine is fermented to. The standard rule of thumb for pressure vessels (as I recall from memory) is use a vessel with 2 times the working pressure rating and 5 times the burst rating; both apply. I have made the mistake of overfilling carboys and even when the airlock comes off it is a huge mess. Mount Vesuvius comes to mind; ceiling, walls, floor _everywhere_; it's a bad day.

To answer the question yeast is affected by pressure from what I have read, yes. No one goes higher than 90 PSIG on wine (on purpose) that I am aware of and most yeasts (other than champagne, imagine that) can get there. I don't think that is the max it can go to or you wouldn't have to be as concerned with the amount of sugar you add for the second fermentation if you wanted a sweet wine.

Don't take this wrong but you may be playing with fire. The chances of it literally blowing up with shrapnel and such may be mitigated by the amount of liquid. Usually liquid filled containers that are breached by internal pressure just split and the energy is wasted by the liquids mass as it leaves. It doesn't go very far and the damage potential is in the immediate area. Gas explosions are another matter, that is how a hand grenade works, literally. This is partially a gas container, it will behave more like that than a solid liquid container.

Airlocks are cheap, you should consider using them instead of the loose cap method. They plug too but the tapered stopper makes sure the explosion goes up, not out. Now if your eye is in the way, it's still bad.

Matthew Suffidy wrote:

I doubt that would happen, the yeast would act like a seal and more likely hold th cap on.

Also, the fill level and outside temperature are factors. A couple of weeks back, I had 2 capped sparkling bottles that were inverted for disgorging pop up their caps. I filled them up in winter and didn't leave much space and when this happened, we had a bout of hot weather for about a week (no air conditiong). No damage in this case, just loss of wine.

Pp

I'll second that, I overfilled some bottles with cold wine and when the wine warmed up to normal room temperatures in the 70's the head-space is about 1/4 inch. It's fine unless you leave it in a car... Synthetic corcs don't tolerate that as well as regular corks, they move easier making for a mess.

Joe

pp wrote:

I don't know about arbitrary pressure, but absolutely enough to detonate a 2L soda bottle.

In my case it wasn't even intentionally wine, it was 2L reserved as fresh grape juice, that for some reason did not get put back in the 'fridge and was left to sit on the counter before leaving for the weekend. Natural yeast was enough to do the job.

The 2L bottle itself split and didn't go very far. I only found small pieces of the cap.

It takes a long, long time and a very sore arm to get the dried sugar off everything. The counter. The Floor. The Wall. The fridge. The Ceiling. The Opposite wall (14 feet away).

____________________________________________________________________ A regular schedule is an assasins best friend.

Well I have never had a 2L coke container explode. The real question was like at a certain pressure like that would be the 'max' pressure from the organic mechanisms. Thanks for everyone responses.

BTW: I did have a situation with boiled grated chunks when I was experimenting with them. They would clog a bottle, and I opened one and it just like went everywhere but I cleaned it up. But yeast really really like boiled potatoes.. !

BTW: I don't have spill over with concentrate and lalvin 1118. Just some sediment at the bottom and hardly, you wouldn't even know it was doing anything really.

If the 2L bottle is filled with liquid and the bottle fails in a significant way (like more than a pinhole), then once the pressure gets too high, a small shot of liquid will fly a long way, but most will make a pretty good puddle right where the bottle was. Since liquid is mostly incompressible, there's just not that much volume change in the liquid to throw it all over the place. The CO2 in the liquid will just bubble out after it opens.

If it fails by making a small hole, a small crack or around the cap, then you can get quite a spray, as the decreasing pressure in the bottle will allow the CO2 in the liquid to expand out of solution and make a great propellant for a while.

You can take a 2L bottle and make an impressive noisemaker (think small bomb sound) by putting in some dry ice, sealing it, and walking away for 5-10 minutes. But you didn't hear it here.

To make your own soda water you usually add enough CO2 to make the bottle 55PSI and normally it will withstand the pressure but at around

Matt, I just came across the answer to this in Birds Wine Technology book. He states 7 pressures at the approximate pressure the yeast suffocate at. I can get you the real title and the page reference if you want to read up on it.

Joe

Joe is sounding cryptic or well-relaxed.. can't quite figger out which....

Did u mean 7 ATM (atmospheres) pressure (i.e. approx 103 psig)?

Gene

Joe Sallustio wrote:

Oops. I did mean atmospheres, around 103 PSIG (PSI Gauge); which means referenced to the general surroundings. PSIA is PSI Absolute, which is referenced to vacuum, like in outer space. I just too geeky sometimes, sorry.

I have the book with me, I'll get the reference out to all.

Joe

Joe Sallustio wrote:

The book is 'Understanding Wine Technology', by David Bird. Page 76. He equates the high pressure to "effectively suffocating" the yeast but then goes on to say if the pressure is reduced, fermentation continues. Sounds like it makes the yeast dormant, not dead.

Joe