A few weeks ago I was watching "Food Science" on PBS. (A television show that is a broadcast of food science lectures at The University of Wisconsin-Madison) On this particular day they explained in detail the fermentation process of sauerkraut. The professor named the particular species of micro-organisms that are involved and the method used to ensure that those are the micro-organisms that you end up with. This is what I remember; 1. Salt eliminates those that are salt intolerant. 2. Keeping the sauerkraut at room temperature causes to gain predominance those micro-organisms that can flourish at that temperature. 3. Cutting off the air eliminates those that require it. 4. One of the micro-organisms that remains produces acid until it expires. 5. the last micro that remains is anaerobic, salt tolerant, room temperature flourishing, and acid tolerant. I was unable to remember which particular micro-organisms were involved, so I e-mailed UW-Madison to see if I could get a transcript of what I saw on television. This is the response I recieved: Hi Gregory Schultz I am answering your question based on info. that i got from a book. <italic>Enterobacter cloacae Erwinia herbicola </italic>These are Gram negative bacteria (rods) that decrease in number with time of fermentation <italic>Leuconostoc mesenteroides </italic>It is a heterotroph that produces lactic acid, Carbon dioxide and flavor and compounds that stimulate the other Lactobacillu (bacteria that produce lactic acid ) <italic>Lactobacillus plantarum </italic>These are the homofermentative bacteria (that produce only acid) that produce 1.7% lactic acid and dominate the microflora as fermentation progresses. Reference: Introduction to Food Fermentation (Text for fermentation course at Kansas State University) by Daniel Y. C. Fung.