Canners: pH testing?
Submitted by murph on 28 October 2007 - 1:32pm. diy | food
Typical recipe collections for canning include a warning, often in bold, all-caps print, along the lines of, "Follow these recipes exactly exactly exactly or you will die of botulism." Now, clearly, what they mean is, "don't adjust recipes in ways that push the pH high enough that botulism can grow," but they don't want the liability of telling people how to make up recipes.
So, can one simply pick up some pH test strips at the friendly local hardware store and use those to make sure that recipes come out to an appropriate acidity? It seems the magic number for botulism is 4.6. Is "pH lower than 4.6" prior to processing sufficient, or is there some buffer needed to account for changes during processing? (Me = not a chemist.)