We brewed beer (Double IPA) for the first time, and we bottled the beer 1 week ago. Now when I look at all my bottles, they all have that white film on the top and I was wondering what it could be? Is it something temporary, or an ingfection? Here's a photo, hard to take a good photo, I hope you'll see what I mean.


EDIT: As asked by Scott, here's a quick run down of sanitation on bottling day:

  • We first washed the bottles with that pink powder soap, then rinsed
  • We sanitised all the equipment with "Aseptox", as well as the table on which stuff was on
  • We boiled water with the dextrose in it, then let it cool down before adding it to the beer
  • the caps were in a sanitized solution
  • Bottles were sanitised before filling them

White film on top

  • Could you edit your question with a quick run-down of your sanitation practices on bottling day?
    – Scott
    Oct 15, 2013 at 4:02

1 Answer 1


While it is difficult to see in the photo, if you're certain that you see a film on the top of the beer, it is with little doubt an infection. There isn't much you can do at this point other than to chill the beer and drink it quickly.

Because it's infected, it's also likely that they'll be over-carbonated. Bacteria like to ferment more than regular yeast can, so they'll consume more sugars than you want, causing over-carbonation (gushers and geysers). By chilling it, you'll slow down this process, (hopefully) buying you a few extra days/weeks before the bottles become gushers or undrinkable.

Because it's over-carbonated, you want to be careful opening them. Try cracking the first bottle in the bathtub or the back porch. Some place where it won't be a complete mess to clean up should you have a geyser. If you do notice that more than one of them are no-joke geysers, I'd recommend storing your bottles in a container to prevent bottle bombs from blowing glass shrapnel into your walls, carpet, dresser, children's eyes, Fido, etc... Tupperware container, large cooler, anything that can contain an exploding bottle. If it's a geyser, it's not far off from exploding, and bottle bombs kill.

As an aside, now would be a great time to look over your sanitation practices. If this happened at bottling, it means something that your beer came in contact with has bacteria in it, be it your siphon, bottling bucket, spiggot on the bucket, hoses, racking cane, bottles, caps, etc... I'd recommend giving your plastics a thorough bleaching (and rinsing), as well as a light scrub with a sponge or something else that's not abrasive and will scratch plastic (giving the bugs a nice little cubby to safely settle into).

  • Could it be a layer of foam caused by the CO2 being produced?
    – mdma
    Oct 15, 2013 at 12:28
  • With bottle conditioning, I've never seen a krausen, and always thought that if I did, I probably overcarbonated. With that said, I also don't stare at my bottles daily to inspect them, rarely pulling them out before the 2-3 week mark. OP, did it appear to be a film, or was it more of a foam? One week is about the tail end of when there would be a krausen, so if it lingers and is still present at the two or three week mark, it's probably not a good sign.
    – Scott
    Oct 15, 2013 at 13:42
  • It really seems to be a film, that stays on the borders of the bottle when inclining it. Oct 15, 2013 at 17:07
  • Doesn't sound optimistic. Try and refrigerate as many of them as possible to slow it down, and (carefully) open one in another week to see how it tastes.
    – Scott
    Oct 15, 2013 at 17:48
  • Tasted it, and it is very good! Now let's see if I am sick tomorrow :) I will risk keeping the bottles at 20°C for another week to get them more carbonated! Oct 17, 2013 at 1:27

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