Ducatiboy stu said:
Bacteria and other various organisms can produce toxins. Sometims its not the organism that is harmfull but the toxins produced. Boiling will kill the organism but the toxin remains. I have read that moulds tend to produce harmfull toxins.
Its just something to keep in mind.
Whilst the above is true in nature. What about in a mash?
Is this speculation or you know of toxins formed in a mash and harmful to whom?
I ask because it is kinda counter-intuitive when you think of sour mashes and Berliner Weissbier - many of which are no-boil.
I would imagine the L. Bacillus would dominate and not give much of a chance for anything else in there.
I have mashed, drained, cooled to 45-50c in the kettle and inoculated the wort with a lacto culture made from raw grain (trying yogurt next). Within 3 days the wort drops to around 3.5pH (L. Bacillus produces lactic acid).
My point being, with the presence of the fast propagating L. Bacillus and the acidity of the wort, human pathogens wouldn't survive and any present would have a hard time taking hold in an overnight mash.
As indicated, an overnight mash
may lead to sourness due to lactic acid, but in my experience it takes longer to form, the bacteria (like yeast) need to propagate. If it has soured (albeit a small amount in a short time) it will remain in the beer but may even be undetectable.
I would simply do a pH test and a taste before running off.
