––––––––
There are two main types of fermentation:
(1) Wild Fermentation. This type of fermentation does not require external introduction of yeast or any similar cultures. Fermented vegetables such as kimchi, sauerkraut, pickle, sourdough bread and some alcohols are all produced through wild fermentation. This involves a simple process of transforming foods into a more appetizing variety through acetic acid fermentation, lacto-fermentation, and ethanol fermentation. As a result, these products cannot be infected by harmful bacteria strains because of the production acetic acid, lactic acid and alcohol respectively.
(2) Starter Fermentation. Unlike wild fermentation, starter fermentation requires the introduction of the appropriate yeast, bacteria, or mold in creating the desired product for instance: fermented dairies such as kefir and yogurt. Cheese, kombucha, wine and beet all require a starter.
There are different kinds of cultures that can be used for fermentation, and each of which is used for producing specific products. For example, a specific strain of bacteria is used when producing beer.
When preparing cultured vegetables, there are several choices of starter cultures. In this case, in fact, starter cultures can be used repeatedly in different batches while there are some that can be taken from the resulting product for later use.