I've noticed what I describe as a "plastic bag burp" property in some beers. In short, beer burps after drinking the beer have a slight plastic-y aftertaste.

I notice this most often in home brew and in some less-than-stellar craft beers, but I also notice it in some (but not all) of the classic bavarian hefes (e.g. Weihenstephan, Paulaner). Given that weissbier connection I'm wondering if it's a sign of a specific ester or phenolic byproduct, specifically sought for in the bavarian beers, and accidentally produced in the home brews.

I'd love to know what specifically that taste might be coming from, and for bonus points how to avoid it when it's not true to the beer style's taste profile.

  • I voted to close this ? because the effect is highly specific to one persons gut physiology. I've never had plastic bag burp when consuming these types of beers. Its a little off topic.
    – brewchez
    Commented Feb 15, 2011 at 13:19
  • 1
    Perception of flavor has everything to do with one persons physiology. Everyone tastes things differently and has different descriptors for what they are tasting. For example, not everyone can perceive diacetyl but it doesn't mean it's not there. I think this question is on topic and relevant to off flavors in beer. Commented Feb 15, 2011 at 15:39
  • Actually I was re-reading the question and I am back on track. I thought at first pass this question was why do these beers make my burps taste like plastic bag. That question should get closed, but NBChris is right, this is a decent question about a flavor in certain beer styles. I don't care for the plastic bag burp descriptor, but to each his own. Sorry
    – brewchez
    Commented Feb 16, 2011 at 13:01

2 Answers 2


It seems to me that you are describing phenols when you talk about the "plastic bag burp" taste. Phenol production does vary quite a bit from one yeast strain to another with the Bavarian weizen yeasts and many Belgian yeasts producing more desirable phenols. Unwanted phenols produce a medicinal, band-aid, smoky, or plastic aroma and flavor. These are often caused by chlorophenols in the water, improper rinsing of chlorine sanitizers, oversparging, sparging with a pH over 6.0, poor yeast health, and wild yeast contamination.

To avoid these flavors you should use a block carbon filter or campden tablets to remove chlorophenols from your water, use a healthy yeast strain, proper sparging while monitoring temperature and pH, and employ a good rinse of chlorine sanitizers or use a non-chlorine sanitizer.

Using a large yeast starter and controlling your fermentation temperature will also decrease phenol production.


I also detected this plastic burp off flavor. I have a vienna lager with this problem. I encountered with it earlier in a german roggenbier. I found it as "styrene" off flavor I think it is more or less meet your decription. I found a referance stating, that it is produced some of the yeast strains for example wheat beer strains. And it can be caused also by defective carbon dioxid gas supplies or a wild yeast contamination. Here is a link, you can find it on the second page.

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