The fermentation process has been used on a wide variety of foods to augment their taste and provide better health by bolstering the digestive process. Lacto-fermentation (also known as Anaerobic fermentation) is arguably the oldest and most widely used of all fermentation processes. Basically, it is the beneficial bacteria, known as Bifidobacterium and Lactobacillus, along with other lactic acid bacteria that breaks down the sugars in plants and converts them to substances that are now easier to digest.
When you walk through an apple orchard and smell the apples that have ripened and fallen from the trees, that is the lacto-fermentation process in action. Other examples include raw milk turning into kefir and raw cabbage into sauerkraut. In essence, any fruit or plant that has sugars is subject to lacto-fermentation.
Lacto-fermentation is really a variation of wild or natural fermentation which happens to ripened food from plants that continue the fermenting process. The difference in this fermentation process is the presence of Lactobacillus which is naturally occurring and found in certain plants. For example, in raw cabbage lactic acid is a byproduct of the lactobacillus which feeds on the sugars in the food.
For the process to work, it must be in an anaerobic or non-oxygen environment, such as inside the skin of an apple. Carrots will also ferment using the lacto-fermentation process, especially when a little salt is added. Because the fermentation uses a specific type of bacteria, it is separate from other forms of fermentation which also use their own types of bacteria.
Fermentation itself is as old as the plants found on Earth. Since life sprang up on Earth over 3 billion years ago, plants that are sugar-based have undergone a form of lacto-fermentation as soon as the lactobacillus bacteria formed.
In human terms, the fermentation process itself was arguably discovered by accident, as most things are, when someone perhaps a hundred thousand years ago or more decided to consume an apple, raw cabbage, carrot, or other plant that had undergone lacto-fermentation. When they discovered how good it tasted and that it did not upset their stomach, these early humans went about finding fruits and vegetables growing in the wild that had undergone this process.
When civilization started sweeping across humanity several thousand years ago, many cultures began to carry fermented fruits and vegetables around because they were still good to eat. One of the many benefits of lacto-fermentation is that it helps preserve certain foods for a long time. As the process became more developed, people began to store fermented food for the winter months. To augment the process, pottery was created with sealed lids so the fermentation process could continue. Quite often, they were buried underground which limited contact with oxygen to an even greater degree. In Africa today, fermentation of different foods is done by placing them in bags and burying them underground.
Today, lacto-fermentation is still quite popular with people creating their own versions using the fruits and vegetables that can undergo the process. In some cases, it is combined with other forms of fermentation, such as culturing to creating new types of foods. Because the process offers benefits to digestion, it is commonly used for those who want to improve their overall feeling of health and well-being.