You might have missed it, but fermented foods were highlighted as one of the food trends of 2018. Which is slightly ironic given that the practice of fermenting foods is thousands of years old.

So what are fermented foods?

Fermentation is a way of creating and preserving foods making use of naturally occurring bacteria. Sometimes, like in the case of sourdough or sauerkraut, it uses organisms just hanging around in the atmosphere, or, for other foods like kefir or yoghurt, yeast/bacteria/culture is added into the process.

Technically, fermentation is the “process of converting [sugars and other] carbohydrates to alcohol or organic acids using microorganisms – yeasts or bacteria—under anaerobic conditions.” (Wikipedia)

Fermentation fell a bit out of favour in Western cultures with our mass produced food systems and food storage advances, such as pasteurisation and refrigeration, allowing us to preserve food. But fermenting has upped its popularity over the last few years and not just among hardcore foodies. Fermented foods have been linked with a healthy gut microbiome, as well as some other digestive benefits, more of which I’ll come on to.

Why fermented foods?

I’m interested in fermented foods for a few reasons.

First of all is the taste! I love the complexity and tangy sourness that fermenting gives food. It makes my tongue dance and I definitely taste with a lot more curiosity as it makes me sit up and pay attention. The flavours can be subtle or strong, but they always add depth. The sourness of fermenting is a good quality to add to meals as it provides freshness and stimulates the desire to eat.

The other BIG reason I’m a fermented fan is related to gut health. Because of my own problems with Irritable Bowel Syndrome (IBS), I try to include regular doses of fermented food in my diet. In the early stages of my diagnosis I experimented with a couple of different good quality probiotics (recommended by my gastro specialist) and although some people with IBS have reported improvements in their symptoms taking, unfortunately it didn’t personally make a huge difference to my symptoms. I’ve therefore opted instead for dietary ways of adding probiotics. Plus this way is a lot tastier! (And in fairness in my particular situation, in hindsight I can see I actually needed to tackle stress and anxiety management in the first instance.)

A third reason I love fermented foods, and this is related to what I’ve just said about stress management, is that fermented foods are a perfect addition to a slow living toolkit. They are the ultimate slow foods for cooks. They often don’t require a lot of interference or manipulation (other than with chocolate and bread), but do require patience and naturally being allowed to develop their own character and flavour.

Some care and attention is involved in creating fermented foods (and lots of experimentation), but I’m still wowed by goes on when some ingredients are pretty much left to their own devices. It’s really the opposite to instant gratification and the “always on-ness” of modern life. And you can’t totally control the outcome which I something love. Yes, you need to guide things along, but then it’s a case of waiting to see (and taste) what happens. Also, the pungent aromas and gentle bubbling burps and parps of certain fermented foods also definitely awaken the senses!

What are fermented foods

A list of fermented foods… (and there are more)

  • Sauerkraut (you’ll ideally want the one in the chiller cabinet or make your own as a lot of the stuff on shelf has been pasteurised)
  • Sourdough (proper sourdough made with a sourdough starter not sour-faux that has simply had a flavouring added)
  • Live yoghurt
  • Cultured butter
  • Cultured/raw cheese
  • Miso
  • Tempeh (similar to tofu, but fermented, which makes it slightly sour, and with a more crumbly texture)
  • Natto (fermented soy beans)
  • Soy sauce
  • Amazake (fermented rice)
  • Pickled vegetables (naturally lacto-fermented, rather than jars of mass-produced pickles)
  • Kimchi
  • Chocolate (well I had to include this didn’t I? Fermenting cacao beans is an important first stage of making chocolate)
  • Unpasteurised beer
  • Kombucha (fermented tea – again not all store-bought versions are equal as extending shelf lift means some of the probiotic benefits are lost)
  • Kefir (normally a fermented milk drink, but you can also get a dairy-free water version)
  • Drinking vinegar (normally using raw apple cider vinegar as a base)

Fermented foods & IBS

Fermented foods are good gut foods as they are full to the brim with probiotics.

Some people with IBS also find fermented versions of foods easier to digest than in other forms. Sourdough is a really good example of this. The long slow fermenting of sourdough, along with its naturally occurring yeasts, breaks down phytic acid in flour, something which can cause gastric issues. It probably also helps that proper sourdough doesn’t have any of the extra additives that are often in mass produced loaves. Similarly in yoghurt, fermenting breaks down lactose into simpler sugars.

I’m particularly excited about some research being run in partnership with Modern Baker, a wonderful sourdough bakery in Oxford, and Newcastle University looking at the impact of various foods on digestion. This will cover a range of foods and a few different aspects of how and what we digest.

As a slight side point, given the links between IBS and mental health issues, anxiety and stress, there are some very interesting observations – though admittedly a few are based on animal studies – on how fermented foods and probiotic administration can support a healthier gut microbiome (which influences mental health). Actually, some of this may be probiotic bacteria influence on brain activity rather than specifically on the microbiome, but there have been indications of reduced anxiety, reduced cortisol production and improved moods as a result of ingesting probiotics and/or fermented foods.

There is still a lot of study needed in this area, particularly as the science connected to the gut microbiome and its impact on our health is relatively in its infancy compared to some other areas of study. However it will be really interesting to see the exact impact of fermented foods on our gut health, and most specifically in relation to IBS symptoms.


Want to have a go at making your own?

It’s actually pretty easy to have a go at making your own fermentables, but I’d suggest trying a few that don’t really need extra special ingredients as a starting point.

Sauerkraut is simply a mix of cabbage, salt and water. Check out “fermentation revivalist” Sandor Katz’s recipe to get your started for sauerkraut.

You can make your own yoghurt by saving a little of your store-bought live yoghurt (full fat preferably) and adding warm milk. Then you just need to put aside some of your homemade yoghurt each time to keep it going.

And a sourdough starter involves water and flour. That’s it! Okay, you do then need to get a few bread making skills under your belt, but the starter can also find its way into biscuits, cakes and pancakes.

A few other fermented foods, like kefir which require grains or kombucha which needs a scoby (both of which you can get hold of online), are also fun to make so don’t let a little extra effort put you off.

As most fermented foods need a little gently tending to, I personally only like to have one or two things on the go at once so I don’t get overwhelmed. But if you’re more organised than me, feel free to go fermented crazy!


Want to find out more?


Some great fermented books to read for cooks

The Art of Fermentation by Sandor Katz (this is pretty much a fermentation bible)

Food for a Happy Gut by Naomi Devlin (nutritionist and River Cottage teacher)

Ferment for Good: Ancient Food for the Modern Gut: Discover the Slowest Kind of Fast Food by Sharon Flyn 

Do Sourdough: Slow Bread for Busy Lives by Andrew Whitley (one of the founders of the Read Bread Campaign)

Modern Baker: A New Way to Bake by Melissa Sharp & Lindsey Stark

(And keep an eye out for Vanessa Kimbell’s book The Sourdough School which comes out in April 2018)


And some fermented fans to follow…

Sandor Katz – www.wildfermentation.comInstagram @sandorkraut

Dr Megan Rossi – www.drmeganrossi.comInstagram @theguthealthdoctor

Naomi Devlin – – Instagram @naomiannedevlin

Cultures for Health – Instagram @Cultures4Health

Modern Baker – Instagram @modernbaker

e5 Bakehouse – Instagram @e5bakehouse

High Mood Food – Instagram @highmoodfood

The Happy Tummy Co. – Instagram @happytummyco



Lopez HW, Krespine V, Guy C, Messager A, Demigne C, Remesy C. Prolonged fermentation of whole wheat sourdough reduces phytate level and increases soluble magnesium. J Agric Food Chem. 2001 May;49(5):2657-62. PubMed PMID: 11368651.

Selhub EM, Logan AC, Bested AC. Fermented foods, microbiota, and mental health: ancient practice meets nutritional psychiatry. J Physiol Anthropol. 2014; 33(1): 2.


What are fermented foods

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