Eli5: How did humans first manage to collect the bacteria used for fermentation?

Question

Like acetic acid bacteria

In: Biology

Answer 1

It is oftentimes naturally present. For example, sauerkraut is made by chopping cabbage and salting it. You don’t need to add any bacterial cultures. This bacteria is already there on the cabbage, you just need to prepare an anaerobic environment to let it do its work.