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~6 hour break between mash and boil

Discussion in 'Homebrewing' started by Brewblues, Aug 24, 2012.

  1. Brewblues

    Brewblues Zealot (95) Massachusetts Nov 25, 2008

    Looking to brew tomorrow while I've got the day off, and planning on trying out the BIAB method, as I'm looking for a smaller batch than would be efficient with my mashtun. Only hangup is that I have to be out of the house for a good chunk of the middle of the day. I was thinking of 'mashing' in the morning, before heading out, and then boiling when I return in the late afternoon. Would likely just cover the pot in the meantime and leave on the stove.

    I've heard that if taking a long break between mash and boil, I should at least bring the mash up to a boil to stop the enzyme conversion. I could certainly make time to do this if need be (or better yet, use my wort chiller to pull the mash back down out of the conversion zone). Does anyone have insight as to:

    A) Whether this is a bad idea in the first place?
    B) If not, is it necessary/recommended to boil/cool the mash after 'sparging', before the wort sits for 6 hours or so?

  2. You don't need to bring the mash to a boil. 10 or 15 minutes at 168-170F would be enough to stop conversion. You should be fine if you remove the grain bag and leave the wort covered on the stove.
  3. mugs1789

    mugs1789 Savant (265) Maryland Dec 6, 2005

    I see no problems with this.

    I often mash overnight for 5 or 6 hours and sparge in the morning. It never hurt my beer and don't think it poses any sanitation issues because it is preboil. I figure that meaningful enzymatic activity is almost complete after the first hour of mashing. The only danger I can think of is that you might get a slightly higher efficiency.

    However, I might think twice if I were using a large amount of heavily roasted grains (black patent, chocolate malt), just in case I get an overdose of that acrid flavor that these grains impart.