As you mentioned, Botulism won't grow in foods with a pH ≤ 4.6.   So  I
didn't think to mention it in regards to fermentation as it is a high acid
process.  

 I should have mentioned that I use a pH meter to determine when my ferments
are done processing.     I have this one because it is waterproof.
http://www.amazon.com/Oakton-EcoTestr-Waterproof-Tester-Range/dp/B004G8PWAU/
ref=sr_1_1?s=industrial&ie=UTF8&qid=1374458194&sr=1-1    I like to wait for
mine to get under 4 just to be safe.  My anecdotal observation is that most
seem to level out at about 3.7 .   My hypothesis being is that this is the
bacteria's ideal environment. 

If you really want to get deeply into the modern science of it, this is what
my professor used as a text in my  global environmental health because many
of these methods are still being used around the world today.
http://www.fao.org/docrep/x0560e/x0560e00.htm#con    There is some
interesting  history and a lot of good information for performing various
traditional ferments but of course, no period reference for the material so
I didn't think to share it.  But it is a good idea to have handle on the
safety issues, if you are thinking of getting into it.   I think it is the
chapter on bacterial fermentation that covers it the issue with aerobic
bacteria getting into anaerobic fermentations.     There was a more recent
study done on water kefir that you can find if you have JSTOR access.   

-----Original Message-----
From: Historical Recreation in the Kingdom of Calontir
[mailto:[log in to unmask]] On Behalf Of Gary and Virginia Phillips
Sent: Sunday, July 21, 2013 8:02 PM
To: [log in to unmask]
Subject: Re: [CALONTIR] pickles

Your local food safety person chiming in, here:

The biggest risk with pickled foods comes from the anaerobic environment,
not one in which oxygen gets in.