Besides forcing me to clean a lot more stuff than I would generally do, will a boil over harm my beer?

I suppose I will loose a lot of the break material and according to brewstrong the break material has proteins vital for head retention, so I would probably have issues with that. Any others?

  • 1
    +1 for the podcast link. Learned something new. I'm not qualified to answer the question, but my research isn't showing any negative effects to the beer...Have fun cleaning. Feb 21, 2013 at 16:03
  • Ditto, I always just thought it was messy, never realized it could actually affect the beer!
    – thanby
    Feb 21, 2013 at 16:19
  • I've contemplated doing a Controlled Boilover to remove the hot break somehow. Like set up a lip in the rim of the kettle to funnel the overflowing foam down away from the sides of the kettle.
    – GHP
    Feb 22, 2013 at 19:54

2 Answers 2


It's no problem for the foam to loose the hot break, since that's made up of denatured (coagulated) proteins. Once the proteins have denatured they don't contribute to the head of the beer - they're insoluble and just fall out and sit at the bottom of the fermentor or keg. (This is covered in the podcast - Jon mentions not boiling the wort too hard to avoid denaturing many of the proteins.)

Depending upon how much beer/hops you loose, you could have these problems:

  • undershooting OG to hit expected post-boil volume, or
  • hitting OG but with smaller post-boil volume
  • reduced IBUs, both from the possible loss of hops, but also decreased efficiency with a smaller volume of wort

But I think you'd have to have one serious boilover for it to make any noticable difference.


You can also lose hops as the liquid boils over, which could affect your final IBU's.

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