After finishing the boil and chilling the wort for my all grain batches I find I always have a large volume of gunk left of the bottom of the pot. I'm sure it's just spent hops and other solid bits from the mash, but it's so thick yucky looking I have not been adding it to the fermenter. The problem is it's a significant part of the batch, ends up being around 4l of a 19l batch.

My question is should I just dump it all in the fermenter and let it settle there, or is leaving it behind the right thing to do?

  • Do you notice a good 'hot-break' about 10-15 minutes into your boil? It will be visile as white-ish flakes of roughly 1 cm. floating in the mostly-clear wort? Or does the wort stay fairly cloudy throughout the boil? It could be a matter of a non-optimal wort pH, both during mashing and boiling. Commented Feb 23, 2015 at 18:45
  • I wasn't looking specifically but I dont recall any white flakes. The wort is cloudy during the boil but quickly clears when the boil stops and the chiller goes in
    – Joe Lipson
    Commented Feb 25, 2015 at 23:24

1 Answer 1


This gunk is what's known as "trub", and it is proteins left over from the hot and cold breaks.

The experiment conducted here: http://brulosophy.com/2014/06/02/the-great-trub-exbeeriment-results-are-in/ seems to show that it doesn't really matter whether it's included in the fermenter or not, but most people still remove it/don't add it.

  • 1
    Leave it behind and account for this kettle loss when you design your recipes. I.E. brew more. Commented Feb 23, 2015 at 16:40
  • 20+% loss of post-boil volume is an absurd thing to build into your recipes, in my opionion. Commented Feb 23, 2015 at 18:26
  • 1
    Excellent link! That should pretty much settle the matter for most of us (sorry, couldn't resist).
    – Glasseyed
    Commented Feb 24, 2015 at 16:37

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