Beginner’s Fermentation: The Basics

What Is Fermentation?

Fermentation is the name given to the action of bacteria, yeasts or other microorganisms. During the process carbohydrates are converted into either alcohol or organic acids under anaerobic conditions.

Fermentation will sometimes happen spontaneously, and can also be encouraged!

Types Of Fermentation

There are broadly 2 types of fermentation – Wild ferments and culture-based ferments.

Wild fermentation, is where you let natural bacteria and yeasts do the work for you. These are simple, as you don’t need to any any kind of starter culture. Examples are sauerkraut and sourdough bread.

Culture-based ferments require the addition of a live starter culture of some kind in order to introduce the desired bacteria and/or yeast colonies. Examples are kefir, kombucha and yoghurt. Technically, starters that are a mixture of yeasts and bacteria in solid form like kombucha mothers or kefir grains are called SCOBYs which stands for Symbiotic Colony Of Bacteria and Yeast.

Benefits Of Fermentation

The chief benefit of consuming live fermented food is the bacteria themselves. These so called ‘friendly’ bacteria work in our gut to digest food and absorb essential nutrients. Gut bacteria play an important role in immunity, and have also been shown to effect our mood an stress levels.

In order to get the benefits of these live bacteria, it’s important not to heat or cook your fermented food or drink, as bacteria are easily killed. Most of the good bacteria will die at something like 55C (around 130F). They don’t mind the cold, though – it’s fine to chill or even freeze your ferments.

In addition to the healthful effects of consuming live foods, fermentation also has a host of benefits that remain if the end product is cooked and the bacteria are killed. The process of fermentation essentially ‘predigests’ food, making it easy for us to process and absorb the nutrients. It also nutralises some poisons, and even creates new nutrients.

That’s the reason that it’s so good to ferment grains and legumes before eating – it unlocks the nutrients, makes them easier on the stomach, and removes unwanted phytates (more on this coming soon)

A good example of this is sourdough bread which (unlike normal commercial bread) has a long fermentation period. It makes the finished product way more digestible, and more nutritious to boot.

Getting Started

If you’d like to get started with fermentation, here are my recommendations for where to start:

Water Kefir


  • Quick turnaround time – Your water kefir is ready to drink in just a few days
  • Versatile, with many flavour options
  • Tasty, even for those who don’t like the flavour of strongly fermented foods and drinks


  • Quick turnaround time – Which means you need to attend to your ferment at least once per week
  • You’ll need to get hold of some water kefir grains to get started

Click for more info: How To Make Water Kefir



  • Extremely easy to make
  • Very cheap
  • No starter required
  • Endless variations of veg, herbs and spices


  • Not many! I suppose this is not the ferment for you if you really can’t stand cabbage…
  • Occasional batches of kraut go mouldy and have to be discarded, but this risk is reduced to (almost) zero if you choose the right kind of cabbage – see note in sauerkraut post.

Click for more info: How To Make Sauerkraut



  • Extremely hardy and tough to kill
  • No equipment to buy


  • Strong flavour, not to everyone’s taste
  • You’ll need to get hold of a starter scoby (‘kombucha mother’)

Click for more info: How To Make Kombucha

Recommended Reading

I highly recommend both of the books by Sandor Elix Katz, and ‘Cultured Club’ by Dearbhla Reynolds. You can read my reviews of them, here:

‘Wild Fermentation’ Review

‘The Art Of Fermentation’ Review

‘Cultured Club’ Review