The answer to the question is, as they say, somewhat complicated. One of my favourite recipes in my cookbook, the Canadian Craft Beer Cookbook, is not really a recipe at all. It’s more of a process – three in fact – for turning good beer into excellent vinegar.
I go through the why’s and how’s in some detail in the book, but the short version is something like this: just as there is a microbial action that converts the sugar in wort to the alcohol and carbon dioxide in beer; there is also one that further metabolizes that alcohol into acetic acid. Different microbes and different results, but they are similar. (more…)