BlueHouseBrewhaus
Well-Known Member
I very rarely post questions because I can almost always do a search to find my answer. But this one has me stumped. Here's the story ...
In my rash, youthful, early days of brewing (last year) I used to always bottle one 24 oz PET bottle along with my glass bottles when bottling a batch. This was my "carb check" bottle. When the bottle got firm I knew the batch was carbonated (now I just wait 3 weeks and trust the yeast). Somewhere along the line I would eventually drink this bottle but sometimes "eventually" could be longer than other times.
Well, tonight I noticed that a PET bottle I had in the fridge from a batch I bottled 8 months ago (Old Peculier clone) had a bit of a bulging top. I opened it expecting a gusher but it stayed in the bottle. I poured it and found it WAY over carbed. It had the spritely fizz of 3.2 volume Belgian even though it was carbed at 2.4 volumes. It also tasted puckeringly sour. No gusher, no ring inside the bottle neck. I dumped it and immediately grabbed a glass bottle of the same brew, which I have been drinking happily for the last 6 months. It was fine, as all the others have been.
So my first thought was that maybe 8 months in plastic had allowed either oxidation or some synthetic off flavor to develop. None of the glass bottles of this brew suffered this fate. I figured if it was an infection, the whole batch would have been infected. I tend to be quite anal about sanitation and have never had an infection so I don't know what that tastes like. I also don't know (or at least have never identified) the taste of oxidized beer.
At this point, my best guess is that the PET bottle had at least one persistent bug tucked away somewhere inside. Maybe it was hidden in one of the little dimples they have in the bottom of the bottle or in some scratch in the plastic that somehow escaped Oxyclean and iodophor.
Has anyone experienced anything similar? Does this sound like oxidation or infection? Do PET bottles have issues with either of those? The good news is that it was only one bottle but it definitely has me stumped.
In my rash, youthful, early days of brewing (last year) I used to always bottle one 24 oz PET bottle along with my glass bottles when bottling a batch. This was my "carb check" bottle. When the bottle got firm I knew the batch was carbonated (now I just wait 3 weeks and trust the yeast). Somewhere along the line I would eventually drink this bottle but sometimes "eventually" could be longer than other times.
Well, tonight I noticed that a PET bottle I had in the fridge from a batch I bottled 8 months ago (Old Peculier clone) had a bit of a bulging top. I opened it expecting a gusher but it stayed in the bottle. I poured it and found it WAY over carbed. It had the spritely fizz of 3.2 volume Belgian even though it was carbed at 2.4 volumes. It also tasted puckeringly sour. No gusher, no ring inside the bottle neck. I dumped it and immediately grabbed a glass bottle of the same brew, which I have been drinking happily for the last 6 months. It was fine, as all the others have been.
So my first thought was that maybe 8 months in plastic had allowed either oxidation or some synthetic off flavor to develop. None of the glass bottles of this brew suffered this fate. I figured if it was an infection, the whole batch would have been infected. I tend to be quite anal about sanitation and have never had an infection so I don't know what that tastes like. I also don't know (or at least have never identified) the taste of oxidized beer.
At this point, my best guess is that the PET bottle had at least one persistent bug tucked away somewhere inside. Maybe it was hidden in one of the little dimples they have in the bottom of the bottle or in some scratch in the plastic that somehow escaped Oxyclean and iodophor.
Has anyone experienced anything similar? Does this sound like oxidation or infection? Do PET bottles have issues with either of those? The good news is that it was only one bottle but it definitely has me stumped.
