I think the area of fermentation is an under-explored genre of food manipulation. At our recent visit to Akelaŕe, a dish described as "milk and grape, cheese and wine in parallel evolution" promised to explore the subject, but while the concept was there, I thought the execution was somewhat lacking.
I've always generally understood how the fermentation process works with wine, with yeast acting to convert the sugars in the grape juice into alcohol. I understood it less with regard to fermented vegetables (i.e., kim chee) and meats (i.e., sausages) until doing a little research. My naive understanding now is that it is in most respects essentially the same process, but instead of sugar converting to alcohol, it is the conversion of carbohydrates into lactic acid by means of beneficial bacteria. It is this lactic acid which both acts to preserve the foods and helps eliminate bad bacteria.
In any event, here's an interesting little interview with Sandor Katz, fermentation maven, on the topic of home fermentation, which in turn led me to his website, Wild Fermentation. I suspect I've had some unintentional home fermentation projects going on at one time or another - this suggests a more purposeful approach.