Digestive Health Fermentation Nutrition

What are fermented foods and why are they so popular?

Kefir, kombucha and kimchee – we answer your questions about the best fermented foods, why they're so good for us and how you can start fermenting foods at home.

During the past few years fermented foods have risen to fame across the UK and are accessible from most common food stores. But what is fermentation and why should you try fermented food?

What is fermentation?

Fermentation is a popular food process where microorganisms such as yeast and bacteria break down a food’s sugars. The initial aim of fermented foods was to increase shelf life, however now people choose to eat fermented foods for their flavour and digestive health benefits.

Without knowing, you’ve probably already eaten plenty of fermented foods such as chocolate, bread and cheese. However,  just because a food is fermented, it doesn’t make it a healthy choice to add to your diet (if only!).

So, which fermented foods are lauded as superfoods, and what can they do for your digestive health?

Some fermented foods act like a natural probiotic supplement, packed full of beneficial bacteria that contribute to the health of the gut’s microbiome. The types of foods, bacteria, and the fermentation process used all influence the health benefits of the final product. Luckily, this cultivating process can be created relatively effortlessly from the comfort of your home!

The best fermented foods you can make at home

1. Kimchee

Kimchee or kim-chi is a Korean classic, spicy, tangy condiment and side dish made of fermented cabbage and carrots.


To make a quick kimchee, mix one sliced Chinese cabbage with a tablespoon of salt and set aside for one hour for the fermentation process to begin. Rinse under cold water, then combine with sliced radish, carrot, spring onion and a sauce of ginger, garlic, chilli sauce, sugar and rice vinegar. Pack into a sterilised jar, seal, and leave to ferment at room temperature overnight before chilling.[1]

2. Sauerkraut

Sauerkraut is one of the best fermented foods for its sour taste, owing to its high concentration of lactic acid.


Start fermenting sauerkraut by washing 2kg of green or white cabbage and then shred finely in a food processor. Layer this with 3 tablespoons of coarse salt in a bowl, and massage for 5 minutes. Leave to sit for another 5, and repeat. Mix in 1 teaspoon of caraway seeds and 1 teaspoon of peppercorns.

Cover the surface of the cabbage with cling film and weigh it down with plates, covering the cabbage completely and pressing out as much air as possible. Leave in a dark place in a cool room for at least 5 days – or up to 6 weeks for the best flavour! Transfer to sterilised jars and keep in the fridge.[2]

3. Miso Noodles Soup

Miso is a fermented soybean product, common in Japanese dishes. Rather than a lacto-ferment, a fungus called Aspergillus oryzae is used to ferment soybeans to create a thick paste that has a strong umami flavour.


Create an easy noodle soup by combining cooked noodles with a broth of soy sauce, miso paste, vegetable stock and wild mushrooms. Add any extras you like, such as tofu, beansprouts, spring onions, carrot and leeks.[3]

4. Kombucha Tea

Every funky cafe and bar has this sour fizzy drink on the menu nowadays – but did you know that you can easily make your own at home?


To make Kombucha tea, you’ll need a scoby – a flat, jelly-like layer that floats on top of kombucha. It contains the beneficial bacteria and yeasts that will ferment plain old tea into probiotic kombucha. Check out your local health food store for leads on how to get one. Then read this easy recipe for the ins and outs on how to ferment, bottle, and carbonate your kombucha.

5. Kefir

Kefir is another fermented drink, but this one uses milk instead of tea making it a sour yoghurt drink, often with a very subtle fizz.


For this one, you’ll need to find fresh kefir grains – but this is one of the easiest ways to begin fermenting foods at home, as all you need to do is place a tablespoon of kefir grains in two cups of milk and wait for 12 – 36 hours. Check out this recipe for non-dairy kefir alternatives.

There is a direct connection between a happy gut microbiome and overall good health. Including fermented foods in your diet is an easy way to boost the number of beneficial bacteria in your gut microbiome, improve your digestion and support your immune system – and fermenting foods at home makes it more affordable and more accessible than ever.


[1] BBC Good Food (2016) Quick Kimchi. https://www.bbcgoodfood.com/recipes/quick-kimchi

[2] BBC Good Food (2016) Simple Sauerkraut. https://www.bbcgoodfood.com/recipes/simple-sauerkraut

[3] BBC Food (n.d.) Simple miso, tofu and mushroom ramen.  https://www.bbc.com/food/recipes/simple_miso_tofu_and_03158