Fermentation is one of the oldest forms of preservation and has been used since the New Stone Age from around 10,200 BC. More recently fermented foods have regained popularity. Not only are fermented foods tasty, they bring a variety of health benefits and their preparation is a fun DIY project.

You’re likely already eating fermented foods in the form of sourdough bread, sauerkraut, kefir, beer, pickles and many others. Increasing your intake of these fermented foods could be beneficial to your health.


Fermentation promotes the growth of good bacteria, yeasts and molds. These good bacteria, yeasts and molds make food more digestible as they break down complex molecules in more simple substances, transforming the chemical composition of food, improving digestibility and therefore nutritional intake by the body. Fermentation also stimulates probiotic functions, which benefit gut flora development which will again aid digestion.

These days, many traditionally fermented foods have been replaced by processed and or highly pasteurized foods. For example, processed breads have replaced homemade sourdough breads and highly pasteurised yoghurt have replaced traditionally fermented yoghurt. Unfortunately processed and highly pasteurized foods are often nutrient stripped. Processing and pasteurization are mainly used for convenience by increasing the speed of production or safety reasons by destroying bad bacteria (sadly also destroying good bacteria in the process).


There are two types of fermentation; first, natural fermentation which occurs naturally from bacteria, yeasts and molds in the air and second, starter fermentation in which bacteria, yeasts or molds are introduced to a food. Starters, otherwise known as fermenting agents, encourage safe fermentation and are easy to use. Fermenting agents come in various forms; packaged starter cultures, salts, alcohol, wild yeast, to a name a few.

Both natural and starter fermentation can take two forms: alcohol or acid fermentation. In alcohol fermentation, yeasts convert sugars into alcohol. Acid fermentation is either acetic acid fermentation where bacteria convert sugar, starch or alcohol to acetic acid or lactic acid fermentation where bacteria and yeasts convert sugar and starch into lactic acid. These fermentation processes preserve fermented foods by creating an environment too acidic for bad bacteria to survive and foods to spoil.

In summary, fermentation offers health benefits, changes the texture, taste and nutritional value of foods and the fermenting process makes for fun DIY projects.

Keen to do some fermentation DIY? Try out this water kefir recipe.