Author Topic: Making yeast starter "wort" in bulk  (Read 1715 times)

Offline denny

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Re: Making yeast starter "wort" in bulk
« Reply #15 on: September 03, 2021, 01:54:34 pm »
It is also the reason why Clostridium botulinum and other pathogens do not grow in finished beer.

Hmm... I usually adjust my mash water to around 5.1 (or whatever my $50 meter thinks is 5.1). I've not measured the pH of my harvested slurry so not sure it's really at 4.6. Should this be something I need to be concerned with when refrigerating yeast for re-pitch?

No.  Only for canned starter wort.
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Offline chinaski

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Re: Making yeast starter "wort" in bulk
« Reply #16 on: September 03, 2021, 05:45:32 pm »
Use a pressure canner, 250 degrees for 15 minutes, 15 psi, nothing survives that. 

Or adjust the wort to have a pH below 4.6 because growth of Clostridium botulinum and the production of its toxin is inhibited below a pH of 4.6.
I would choose the pressure canner as the most conservative method.  I'd hate to find out the hard way that my pH meter was reading high.