Bottles are just randomly exploding...?

[McBrewski]

So I made a Pirate Ale recipe posted on here which is pretty much a dark brown/black ale with 1.5L of coconut rum added prior to bottling. I added 5 oz. of priming sugar mixed with boiled water to the 5 gallon batch prior to bottling. I read on here a couple days ago that yeast may die/have trouble carbonating at unusually high abv levels so I went down in the basement to rouse the yeast in the bottles.

I went down today (two days later) to check it out and there was the neck of a broken glass bottle just sitting in the middle of the floor. Apparently one of the bottles just sporadically exploded. Before I had even roused the yeast in the bottles, there were a few broken as well, but I had just assumed that was due to stacking heavier bottles on top of them or something.

Did I use too much priming sugar? Is it because of the high alcohol content? Has the beer been contaminated? Could it be because of the pressure inside my basement? I filled all the bottles uniformly, and all have the same exact space from liquid to cap.

 

[BreWirfel]

your coconut rum also had sugar in it, which may make your carb levels too high??

 

[ChshreCat]

From what I've read there are carbs but no sugar left in the rum, but nutritional information on bottles are listed by 1oz serving and if something is below a gram, they list it as zero. So, maybe there's enough in an entire bottle to cause you problems. I dunno for sure.

What was your FG?
Was your FG stable?
How much headspace do you have in the bottles? Too much can cause overcarbonation.
Did you make sure the priming sugar was completely mixed in your bottling bucket?
And why are you rousing yeast in the bottles?

 

[McBrewski]

Didn't take an FG just cause the rum was going to **** the true reading anyways. It spent a week in primary and 2 in secondary. I don't know if the FG was stable or not - I assumed it was.

Headspace is 1-2", I use a bottling wand, so I fill it up to the top then remove the wand and thought that was sufficient space for the carbonation. Yes, I siphoned the beer softly on to the priming sugar so it mixed in evenly.

I explained that I was rousing the yeast because I read on here that high alcohol levels can cause problems with carbonation, so I figured it would help. However, the bottles were exploding even before I roused the yeast.

I just opened up a bottle that I took for a sample, and it is extremely over-carbonated...

=(

 

[ChshreCat]

I'd say odds are it's overcarbed and exploding because it wasn't finished fermenting. Using your hydrometer will help you avoid these sorts of problems.

You want to get your FG so you know if it's finished, not just for the sake of knowing what it is, so having the rum change it wouldn't be an issue.

Next time, check your FG and make sure it's in the target range. Then wait a few days and check it again to make sure it's stable.

As for this batch... you could try uncapping them all and recapping them to let off some pressure, then getting them all in the fridge to stop them from fermenting further. When yo uncap, wear some protective clothing, gloves and eye protection in case one explodes in your hand. It happens.

I wouldn't rouse the yeast in the bottles unless you have a problem with them not carbonating. It's not really a standard procedure to be performed on every batch. It's more of a fix in the event you do have a problem.

 

[McBrewski]

Alright, cool thanks man. The beer still tastes really good. There wasn't activity in the airlock for at least one and a half weeks - I thought that was good enough proof that fermentation was done. I guess not.