With the fermentation craze growing fast, by now perhaps you’ve seen kombucha or kefir - but what actually are fermented foods and what does the science say?

What is fermentation?

Fermented foods have been altered by the action of ‘friendly’ bacteria and/or yeasts, usually with a little help from us. Wild fermentation occurs when we let the bacteria that are naturally present on vegetables do the work. Lactic acid bacteria (LAB) feed on the nutrient source and in the process create lactic acid, which acts as a preservative. Meanwhile, they produce a host of vitamins, minerals, and bioactive compounds, and manage to be delicious, too.

This process preserves them, but also changes the flavour too, giving it tangy, strong and slightly sour flavours. Things like beer, yoghurt, sauerkraut, sourdough, pickles, kombucha and vinegar all get their distinctive flavours from different kinds of fermentation.

In many countries, people have a long tradition of using vinegar and sugar to preserve fruit as jams, relishes, and chutneys. In Eastern European and Asian cultures, they have been fermenting vegetables a few centuries ago.

“Fermentation is a wondrous form of not only creative expression but also a life long skill," said Tash, the co-founder of AvantGardenLife. "It shows us how beautiful transformation can be, to be patient and to care for the food and drinks we ingest, connecting us on a deeper level to nature."

How to get started

Despite the rumours, fermenting is surprisingly little effort – once you’ve prepared it, you just leave it and allow the microbes to do all the hard work. You can later return to a dish that’s transformed and ready to serve. Some fermented foods (such as kimchi or sauerkraut) do require more love and care, but there are plenty of time-efficient options, including kefir and yoghurt.