27 January 2012

"Beer oyster" explained


This question was posed at Reddit:
At an engagement party last weekend, my husband enjoyed a Beck's. He decided he would like to enjoy another and so opened this bottle, took a sip and cringed. His beer tasted awful and he wiped off what looked like dirt from the bottle cap. He held the beer to the light and the liquid was murky through the green glass there was something floating in it. We go in to the kitchen, pour the beer down the sink and something slipped out. I turned it over and it kind of looked like a mushroom and smelled a whole lot like shit. This image is the bottle and the offending object.
Answer below the fold (it's not offensive - just giving you a moment to ponder...)
Two of the comments:

That's a Beer Oyster. It was caused by a pasteurization failure, the beer was not heated to the right temperature. Leftover yeast/bacteria were able to use the leftover air in the top of the bottle to survive and make a slimy, stinky mess. Source: My mother and brother work for major beer companies.
Close. At 2-3 minutes the pasteurization of 140F isn't going kill the yeast. Also through fermentation the environment is already inhospitable to the yeast. It has fermented out and can ferment no more. If it isn't fermenting it isn't reproducing. It isn't building yeast cake. Even so this would appear as a light film on the bottom as in a bottle conditioned beer.
What you are seeing is most likely a plate filter failure. It's going to be a mix of proteins, yeast and hop matter. Filter probably let loose a clogged bit at the end. It's unlikely to be an infection if the others were unaffected. Source: Homebrewer for 15 years, have brewed at a micro brewery.

13 comments:

  1. Thanks :P Just as I am actually drinking from a bottle of beer, you'll have me examining the contents of the next 6!

    My guess was in improper seal of the cap and somehow a mold or fungus had grown inside> Had that happen before, but was smaller than a pea.

    ReplyDelete
  2. I wonder what's worse - almost swallowing one of these, or almost swallowing a cigarette butt some idiot has doused in your beer!

    ReplyDelete
  3. I never confirmed this but saw in a documentary that pasteurization was invented with beer in min, not milk

    ReplyDelete
    Replies
    1. It's easy to confirm with a few clicks.

      http://en.wikipedia.org/wiki/Pasteurization#History

      Delete
    2. Wikipedia confirms nothing.

      Delete
  4. Who was it that said that humanity would have perished from their own filth if it weren't for beer (fermentation, which kills most harmful bacteria) and tea (boiling, ditto)? All kidding aside, there's probably a good measure of in this premise.

    ReplyDelete
  5. Just came in from getting another batch of home brew into fermentation, and this must be part of the reason we're told to always drink our beer in glasses. Bottles can be scary!

    ReplyDelete
  6. I would like that tan line explained. Why do people still artificially tan... and in January?

    ReplyDelete
  7. proto-marmite, -vegemite?

    Speaking of:

    Eli- You have a point, but that's an Aussie Bewb. It's summah down undah.

    I can't even do accents when I'm typing.

    ReplyDelete
  8. If it were just a mix of proteins, yeast and hop matter it would smell fine. That is bacterial and it wouldn't grow in a beer with any significant (2 or 3%) alcohol content, pasteurized or not. I once cleaned a gelatinous blob like this from someone's filthy plate filter machine but anything visible to the naked eye won't pass though the filter pads. Most likely it was dried and caked to the bottom of the bottle making it resistant to the automated washing system. It slowly re-hydrated and loosened itself. Makes me glad I brew my own.

    ReplyDelete
  9. looks like a SCOBY to me

    ReplyDelete
    Replies
    1. clarification: "Symbiotic Colony of Bacteria and Yeast"

      Delete

Related Posts Plugin for WordPress, Blogger...