My first PET plastic bottle bomb

[BrewingWisdom]

Last night it was around 2 am when I was sleeping like a baby , a loud explosion literally like a bomb blast woke me up lol.
First I though robbers are in my house or a war between india and Pakistan has started
When I recovered from a shock and came to my senses I looked towards my wooden cupboard and a liquid was coming out of it. Then I got it. I opened the cupboard and it was a mess inside. One of the eight bottles of my sugar cane wine was exploded , the 1 litre bottle of coke was torn into two and not just that it also broke into two the empty fermenting plastic bucket next to it. Fortunately I am still left with a spare fermenting bucket and the blast didn't affected the rest of the wine bottles. It took me good half an hour to clean up the mess.
I was surprised to know it was so intense that literally the force of Co2 broke not just the highly resistant psi bottle but also the thick plastic bucket. I am sure if there were metal sharpnels in the bottle it wasn't any less than a hand grenade.
The silly mistake I made was during pitching the yeast. The bucket was filled to the top and there was no space left for the lid to close and the airlock to operate freely so to make a space I put the extra liquid in a empty coke bottle that went through the whole fermentation process. After few days i released the CO2 pressure by opening the bottle but it somehow accumulated again. The yeast was a high tolerance 18% abv wine yeast and I ended up with a 10.36% abv batch so you can imagine the amount of CO2 generated inside.
It was a good lesson learnt lol and my advice to all of you here to start taking PET plastic bottles seriously as I've seen some people talking here that pressure rated plastic bottles can't explode like glass bottles. They maybe less dangerous than glass bottles but still they can inflict a serious body damage.
Cheers

 

[doug293cz]

Those fermenting PET bottles are are dangerous, and you are in danger if you try to move them without wearing heavy protective gear: strong goggles, a strong full face shield, all of your skin covered by very heavy clothing, including your head, neck, and hands. You would be safer leaving those bottles in the cupboard, and waiting for them to explode, rather than trying to handle them, and not even opening the cupboard until they all explode. Yes it will make a huge mess, but that beats serious bodily injury.

You should never, ever, do primary fermentation in a sealed container, even one that is pressure rated. A 20 liter fermentation going from 1.050 OG to 1.010 FG will produce about 450 liters of CO2. So, your 1 liter fermentation could produce about 22 L of CO2 at atmospheric pressure. If you constrain that CO2 in about 0.1 L of headspace, the pressure will be about 220 atmospheres or more than 3000 psi (220 bar.)

PET soda bottles can handle somewhere between 50 and 100 psi. This is fine for bottle conditioning (carbonating) but not fermenting when sealed.

Brew on

 

[BrewingWisdom]

Those fermenting PET bottles are are dangerous, and you are in danger if you try to move them without wearing heavy protective gear: strong goggles, a strong full face shield, all of your skin covered by very heavy clothing, including your head, neck, and hands. You would be safer leaving those bottles in the cupboard, and waiting for them to explode, rather than trying to handle them, and not even opening the cupboard until they all explode. Yes it will make a huge mess, but that beats serious bodily injury.

You should never, ever, do primary fermentation in a sealed container, even one that is pressure rated. A 20 liter fermentation going from 1.050 OG to 1.010 FG will produce about 450 liters of CO2. So, your 1 liter fermentation could produce about 22 L of CO2 at atmospheric pressure. If you constrain that CO2 in about 0.1 L of headspace, the pressure will be about 220 atmospheres or more than 3000 psi (220 bar.)

PET soda bottles can handle somewhere between 50 and 100 psi. This is fine for bottle conditioning (carbonating) but not fermenting when sealed.

Brew on

The rest of the bottles are just fine. They completed their primary fermentation in the bucket and moved to bottles only after the gravity was dropped below 1.000 so with no further sugar to eat , there won't be any CO2. Though that wine will be very dry.

 

[IslandLizard]

We've all made unintentional (and occasionally even intentional) submissions to the Darwin Awards at times.

I'm really glad to hear you can talk about this without sustained injury. It could have ended much, much worse.
You are one lucky guy!

 

[BrewingWisdom]

We've all made unintentional (and occasionally even intentional) submissions to the Darwin Awards at times.

I'm really glad to hear you can talk about this without sustained injury. It could have ended much, much worse.
You are one lucky guy!

Yeah man I almost won a Darwin award last night

 

[doug293cz]

The rest of the bottles are just fine. They completed their primary fermentation in the bucket and moved to bottles only after the gravity was dropped below 1.000 so with no further sugar to eat , there won't be any CO2. Though that wine will be very dry.

Sorry, I didn't realize that the other PET bottles weren't being used for primary fermentation.

Brew on

 

[IslandLizard]

Sorry, I didn't realize that the other PET bottles weren't being used for primary fermentation.

I had to reread the OP a few times to figure that out too:

The silly mistake I made was during pitching the yeast. The bucket was filled to the top and there was no space left for the lid to close and the airlock to operate freely so you make a space I put the extra liquid in a empty coke bottle that went through the whole fermentation process. After few days i released the CO2 pressure by opening the bottle but it somehow accumulated again.

I reckon there must have been quite some blow off with such little headspace in the fermenter.

 

[BrewingWisdom]

I had to reread the OP a few times to figure that out too:

I reckon there must have been quite some blow off with such little headspace in the fermenter.

Yes the fermentation in the bucket was vigorous.
But I think the headspace was good enough.
Finally sorry if my broken English is causing you native English speakers a difficulty.

 

[IslandLizard]

Yes the fermentation in the bucket was vigorous.
But I think the headspace was good enough.

If you didn't have any blow off, yes, the headspace was indeed adequate.

We usually want to leave a minimum headspace equal to 1/4 of the batch's volume. For example an 8 liter batch would require a minimum of 2 liters of headspace, so a 10 liter vessel would be the bare minimum.

With some yeasts, such as true top fermenters and others known for being very active, producing large amounts of krausen, a roomier headspace may be a wise decision. Same reasoning when fermenting at higher temps.

Finally sorry if my broken English is causing you native English speakers a difficulty.

No need to apologize. You're doing very well, and not just with English! We always appreciate the extra efforts non-native English speakers need to take to communicate here.
The forum format itself is not the most conducive for getting exact details across. For one it lacks real-time interactivity. Maybe, one day...

 

[TomSellers]

Years ago I was fermenting in a glass carboy in a closet, using a simple blow-off valve consisting of tubing in the middle of a rubber stopper bubbling into a bottle of metabisulfite. We went out for the day, and I did not realize the krausen was up past the shoulder of the carboy and starting to form in the neck. EG: it was running out of head space for the krausen to expand into. When it did run out of space, the krausen plugged the narrow neck of the glass carboy. We had just arrived home, and heard an explosion. It did not take long to realize what had happened when entering the room and seeing 5 gallons of wort seeping out from below the closet door. When I opened the door, there were large shards of glass embedded into the back of it, and the wall. I immediately ordered 2 All Rounders with spunding valves. Needless to say, that was the last time I ever fermented in a glass carboy with a narrow neck. Carpet had to be torn out and discarded. I see from this post PET is also not without it hazards, so I think the main advantage of using a wide mouth PET fermentation vessel would be 1) due to having more head room than a traditional glass carboy with respect to fermenting a standard 22l batch, and 2) cleaning is easier. Now I can place digital hydrometers into my ferments, and ironically most of my brews now are pressure fermented, including ciders. I can see why the days are numbered for narrow neck glass carboys since modern times have given us more sensible alternatives.

 

[BrewingWisdom]

Years ago I was fermenting in a glass carboy in a closet, using a simple blow-off valve consisting of tubing in the middle of a rubber stopper bubbling into a bottle of metabisulfite. We went out for the day, and I did not realize the krausen was up past the shoulder of the carboy and starting to form in the neck. EG: it was running out of head space for the krausen to expand into. When it did run out of space, the krausen plugged the narrow neck of the glass carboy. We had just arrived home, and heard an explosion. It did not take long to realize what had happened when entering the room and seeing 5 gallons of wort seeping out from below the closet door. When I opened the door, there were large shards of glass embedded into the back of it, and the wall. I immediately ordered 2 All Rounders with spunding valves. Needless to say, that was the last time I ever fermented in a glass carboy with a narrow neck. Carpet had to be torn out and discarded. I see from this post PET is also not without it hazards, so I think the main advantage of using a wide mouth PET fermentation vessel would be 1) due to having more head room than a traditional glass carboy with respect to fermenting a standard 22l batch, and 2) cleaning is easier. Now I can place digital hydrometers into my ferments, and ironically most of my brews now are pressure fermented, including ciders. I can see why the days are numbered for narrow neck glass carboys since modern times have given us more sensible alternatives.

These CO2 fermentation explosions are no joke brother.