Everything You Need to Know About Food Fermentation

Everything You Need to Know About Food Fermentation

Ever wondered why health nuts promote yoghurt, kombucha and kimchi, and why food that is cultured (i.e. fermented food) is supposedly good for you?

We’ve teamed up with nutritionist and food scientist Martolis Pieters from @truebitenutrition to tell you everything you ever wanted to know, and some things would never have guessed, about fermentation.

In this blog, you will learn:

  1. What is food fermentation?
  2. The types of food fermentation.
  3. The benefits of fermented food.
  4. Can you ferment food at home?
  5. How to incorporate fermented foods into your diet.
  6. What to look for on the packaging when buying fermented food.

1. What is food fermentation?

Food fermentation is an ancient method of preserving food. It uses bacteria or yeast to break down carbohydrates into acids, alcohol or carbon dioxide, as well as anti-microbial metabolites, which preserve the food.

For example, wine, beer and cider are the fermentation of sugar into ethanol. Sourdough bread is the fermentation of carbohydrates into CO2, which causes the bread to be spongy and slightly tart. Sauerkraut, kimchi and yoghurt are the fermentation of carbohydrates into lactic acid, which preserves the food.

Fermentation, in some cases,  also leads to the growth of good bacteria, aka probiotics, which are good for gut health. Fermented foods tend to have a tart taste.

Did you know?
The oldest known record of fermentation is beer residue that was found in a cave in Israel and is about 13,000 years old.

2. What types of food fermentation are there?

There are two types of fermentation – aerobic and anaerobic.

Soy Sauce

Aerobic fermentation

Aerobic fermentation uses bacteria that thrive in the presence of oxygen and includes alkaline and fungal fermentation. Foods such as soy or sake are started with fungal fermentation. Alkaline fermentation is mainly practiced in Southeast Asia and some parts of Africa and includes foods such as Japanese natto.

Anaerobic fermentation

Anaerobic fermentation is the more common form of food fermentation and includes lactic acid fermentation, alcoholic fermentation and brine ferments.

Alcoholic fermentation is a complicated biochemical process that converts sugars into ethanol (and a few other things). Examples are alcoholic beverages, such as wine and beer.


Lactic acid fermentation (lacto-fermentation) is the most common and easiest method of fermentation and includes foods like kimchi, sauerkraut, sourdough, yoghurts and kefir.

Brine ferments
are usually vegetables with salt or a saltwater mix added to draw out the water in the veg. The salt then dissolves in the water forming the brine. An example of this is fermented brine cucumbers.

3. The benefits of fermented food


A delight to the senses

Fermentation enhances the organoleptic properties of food. The what? Pieters explains that organoleptic “refers to sensory properties, such as the smell, taste, texture, and colour of foods. Think of yeast-raised bread vs. sourdough bread. Sourdough has a distinct ‘sour’ taste, and it has large air pockets giving it a less dense and more spongy texture.” So, basically, fermentation makes a very satisfying sensory explosion in your mouth.

Good digestion

It takes the effort out of intestinal absorption

There’s a yummy thought. Our bodies need to absorb the vitamins and nutrients from the food we eat for biochemical processes (bodily functions) to be possible. Fermentation helps this absorption process by starting to digest the large proteins and sugars for us, so that we can more easily absorb all the goodness.


Potentially packed with probiotics

Probiotics are healthy bacteria that keep your gut functioning at an optimal level. Some fermented foods are high in probiotics and these aid your digestive function and could even help with digestive issues, such as IBS. Probiotics are also known immune boosters, so a cauldron of kimchi or a serving of sauerkraut could help you ward off colds and recover more quickly.

Just note: not all fermented foods have probiotics.

If they have been put through high pressure or high temperature, they won’t have probiotics. Some fermented food has been pasteurised to preserve shelf life and then has had live cultures added to give you active probiotics.


PRO TIP: A good guideline is that if they are in the fridge, they probably have live active cultures. If they are on the shelf, they probably don’t. Be sure to check the label.

4. Can you ferment food at home?

Yes, you can. You do have to be careful though as you need a clean and sterile environment to ensure your fermentation doesn’t get contaminated.

There are ways to avoid this, such as following the recipe you are using to a tee, checking your pH levels (most dangerous bacteria can’t grow at a low pH), checking for mould growth, releasing CO2 by ‘burping’ your mix, and refrigerating as soon as it’s fermented.

We will cover this in our next blog when we give you a step-by-step guide to home fermentation.  


5. How to incorporate fermented foods into your diet

  • You can replace your usual bread with sourdough.
  • You can add yoghurt to your morning smoothie or muesli.
  • You can use tofu or tempeh as a protein for your meals.
  • You can add sauerkraut, kimchi or fermented veg to salads or use them as sides for meals.
  • You can replace soda with kombucha.
  • You can make fermented sauces to add to food, such as a fermented tomato sauce.
  • You can have an ice-cold beer or a nice glass of wine. (Kidding! Alcohol is a by-product of the fermentation of grapes and doesn’t have much nutritional value.)  

Did you know?  

Coffee is (sometimes) a fermented product. The wet method of producing coffee involves the fermentation of the coffee bean. And the first part of the process of making chocolate is, you guessed it, the fermentation of the cocoa bean. Pieters notes, “Dark chocolate has a lot more of the cocoa solids, which have more nutritional content.”

6. What to look for on the packaging when buying fermented food

Not all fermented food is created equal. Look for active cultures in or added to the product, and for products low in preservatives (those pesky E-numbers – refer to our blog on How to Read Nutritional Labels). The label should say ‘active cultures’ or ‘live cultures’.


Fermented foods are yummy, good for you and last for a good long while. Get some culture in your life and your gut and palate will be singing and zinging.

You can ferment foods yourself, but you need to be careful to do it right. To help you with that, look out for our next blog on A Step-by-Step guide to Home Fermentation.


Share on facebook
Share on twitter
Share on linkedin
Brand New Packages!
Click image to view packages

Lisa Parsons

Lisa is a content writer and strategist with experience across many platforms. She is also a personal trainer and has a keen interest in holistic health encompassing physical, mental and emotional wellness. She enjoys travel, books, puzzles, learning languages, and a buttery Chardonnay.

This Post Has One Comment

Leave a Reply