Lacto-Fermentation

All fruits and vegetables are naturally covered with a layer of microorganisms. These microorganisms will start the fermentation process when the vegetable or fruit begin the break down. For this to happen, certain criteria need to be met, such as the right temperature, the right amount of salt, and an anaerobic (oxygen-free) environment. From a culinary point of view fermentation is an amazing way of preparing the food, changing its texture, and intensifying and enhancing its flavors and aroma. On top of this the nutritional value of the food will increase and it will become more digestible, helping us to feel good after a meal rather than too full and bloated.

Scientifically, fermentation is a spontaneous microbiological metabolic process by which the microorganisms covering the vegetable will start to break down carbohydrates or sugars in the food and turn them into an organic acid, alcohol, or gas. Vegetables and fruit are naturally high in lactic acid bacteria which turn the sugar in the vegetable or fruit into lactic acid (hence lacto-fermentation) which in turn reduces the pH level of the ferment. The salt added to the ferment is also loved by the lactic acid bacteria, and not many other bacteria can survive in those conditions (high acidity plus high salinity).

This lacto-fermentation happens in two stages:

  1. Firstly, a bacterium called Leuconostoc Mesenteroides breaks down the sugars in the vegetables and starts to create lactic acid, lowering the pH, and changing the environment inside the fermentation container.

  2. At the second stage, the pH is so low that the Leuconostoc bacteria are less able to thrive and instead other lactic acid bacteria start to take over (like Lactobacillus Plantarum, Lactobacillus Curvatus, and Lactobacillus Brevis). Other products apart from bacteria are also being produced now, like acetylcholin, B-vitamins, vitamin K, and various enzymes. At this stage, the pH will be around 3.8 and can go down as low as 3.4. In this acidic and salty environment, lactic acid bacteria are pretty much the only bacteria that can survive.

Despite having such a low pH, the ferment has no acidifying effect on the human body; when it’s broken down it actually has an alkalizing effect. These two stages take approximately 4 weeks in total.