Fermented foods: boost your immune system with kefir.

Kefir is having a bit of a moment in my house. I’ve been wanting to do more fermenting since early summer when I intended to go back to making kimchi, the Korean pickles made by fermenting root vegetables.

I didn’t get around to the kimchi but, when we were in France last month, I came back to home-fermentation when I realised how much yoghurt my daughters get through. I thought of all the plastic waste and the fact that most shop-bought yoghurts are high in sugars and low in (m)any live cultures. I started to think how I could boost my family’s pre-winter immune system by introducing more probiotics, via fermented food, into our diets.

What are fermented foods?

Fermentation happens with the help of micro-organisms such as bacteria, yeasts and other micro-organisms. When we think of fermented foods, we generally think of alcoholic drinks, cheese, and the big fermentation craze of lockdown, sourdough. Oh, the desperation and long wait for that starter! 

However, there’s no end of foods and drinks that can be fermented, from beans (just think of miso and tempeh), grains (breads, soups, porridges), tea (kombucha) and dairy (yoghurt, kefir, labneh). The process of fermentation can transform food, breaking nutrients down and making food more digestible, more flavourful – and nutritious. 

Why are fermented foods good for us?

We have trillions of bacteria and other microorganisms in our digestive tract and research shows that a diverse and healthy microbiome is super important for digestive health, our immune system and to protect against disease. Consuming food rich in live-cultures (or probiotics) helps colonise the gut with a spectrum of mirco-organisms to ensure an active and healthy microbiome. 

Unfortunately, many shop-bought or mass-produced fermented foods tend to be pasteurised or heat-treated, so they contain little or none of these micro-organisms that are so beneficial to our health. Uncooked fermented foods, on the other hand, are rich in live-cultures.

To guarantee probiotic-rich foods it’s best to make them yourself and one of the simplest things to make is kefir. 

Kefir is a fermented milk drink. It has a legacy as one of the oldest milk ferments, originating roughly 2,000 years ago. It is made with just two ingredients - kefir grains (the micro-organism starter) and milk. You can use any milk, including plant-based options.

Is kefir healthier than yoghurt?

Most of kefir’s superior health benefits can be attributed to its variety and number of micro-organisms. Kefir is made with a combination of bacteria and yeast ferments, whereas yoghurt is made with just bacteria ferments. Over 50 variations of bacteria and yeasts have been identified from milk kefir. I bought my starter grains from Freshly Fermented and they apparently contain over 20 strains. 

Kefir also has higher levels of fat and protein than yoghurt. A 250ml serving of whole milk kefir is 145 kcal with 8.3g of protein and 7.5g of fat (source: BBC Good Food). 

Thinner than yoghurt, like other milk ferments, kefir can generally be digested by anyone who’s lactose intolerant. I’m not a dairy fan but enjoy the tart creaminess of cow’s milk kefir. I also get how its sourness may not suit everyone.

You can have too much of a good thing, however. It is advised to keep daily consumption of kefir to 250-300ml/day. Side effects of having too much of this potent probiotic super drink include bloating, gas, stomach cramps and diarrhoea.  And yes, I can attest to all of the above these past few weeks!

How do you make kefir?

It’s straightforward to make. You just need kefir grains - cottage-cheese looking clumps of microorganism starter - and the milk drink of your choice (I’m using organic milk at the moment but will be experimenting soon with my homemade almond milk, soy and coconut milk). 

Just place your milk (I make between 500ml and 750ml at a time) and kefir grain starter in a fermenting jar, or any glass jar using kitchen paper as a cover, for 24-48 hours at room temperature. Strain out the grains – which you can then use to make your next batch – and decant the kefir into a glass bottle or jar. Store in the fridge until you’re ready to consume. 

Culture club

You can buy and use dried cultures. These apparently make up to 7 rounds of kefir. I made three really good batches but then gave this to my sister as my live grains had arrived - and I needed to reign in my kefir production! So far the kefir with the grains is not so creamy but apparently it takes a few weeks for them to recover and full activate after being shipped.

Now, onto looking after the kefir grains. This is turning out to be quite a responsibility – an obsession even these past weeks. They require continual feeding and it feels like I have a Tamagotchi rather than a food culture! The sense of horror when it looked as if all the grains had ‘dissolved’ in my latest batch - and the rush to internet search ‘can you kill kefir grains?’ felt like a stress too far! They seem to be okay again now.

As I’ve not managed to get anyone else in the house to drink it neat so far - and it is very easy to over-produce - I need to be careful I don’t end up consuming too much of it. However, it’s a wonderfully healthy and tasty base for smoothies and is so much cheaper, environmentally-friendly and live-culture-rich than shop-bought kefir. I intend to keep making and consuming it for as long as my grains stay alive! 

Recipe

Mango and turmeric kefir smoothie

Blend the following together for a refreshing, light smoothie rich in antioxidants, probiotics, vits and minerals.

250ml kefir

100g mango (fresh, dried or frozen)

1/4 tsp turmeric 

Further reading

Wild Fermentation – Sandor Ellix Katz

Getting set up

thekefircompany.co.uk

freshlyfermented.co.uk

Lakeland (for fermentation jars)