Food & recipes

A Beginner’s Guide to Fermenting

Are you ready to cultivate the live foods that’ll transform your health? Here’s how to get going

Have fresh kefirs and raw krauts found their way into your shopping basket over the last few months? So good but expensive, right? Finding great ferments on the supermarket and deli shelves is a true joy, but did you know they’re some of the simplest, cheapest and most satisfying foods you’ll ever make? There’s plenty to say about the how of fermenting, but first the why, because foods alive with the right sort of microbial life really are pretty incredible. “They can increase absorption of certain nutrients, such as folate and vitamin B12,” says clinical nutritionist Amaeze Madukah (lifesrecipe.co). “Some fermented foods may potentially contribute to reducing blood pressure, increasing immune support, helping brain health, and in some cases, helping blood glucose management.”

From kombucha to kimchi and water kefir to fermented wild garlic, the nutritional load of home ferments will be influenced by many different factors, but adding just a few ferments to your kitchen repertoire could add up to a big change for your gut. “It’s really important to have a diverse diet, especially including varied fruits and vegetables, because they contain a variety of nutrients and help to diversify our gut bacteria, which helps to strengthen our gut,” says Amaeze. “No single food contains everything that helps your gut, so it’s good to diversify your diet to make sure you’re getting all of those gut-loving nutrients.” Ready to get started? Here it goes!

1. Choose your ferment

Recipes, video tutorials and tips covering anything from fermented chilli sauces to milk kefir are easy to find, but a great project for beginners is sauerkraut (see panel). “You see the transformative effect of fermentation so readily,” says Katie Venner, who runs fermenting classes from her Somerset bakery and fermentaria (tracebridgesourdough.co.uk). “Taste it as a coleslaw-type salad as you pack it into the jars, and then two or three weeks later, the difference is amazing – still crunchy but really tasty.” The transformation of familiar flavours into a rainbow of sour and umami notes is a magical process that you can roll out to pretty much any vegetable. “If you’re worried about heady aromas, don’t put too much of the onion and garlic family in your kraut,” advises Katie. “Their sulphurous odours can be off putting for some people.”

2. Wash your hands

Always important when cooking, good hygiene is fundamental when you’re planning to keep foods at room temperature for weeks at a time. Inviting live microbes to populate your foods may be a daunting prospect, but remember that home cooks have been safely fermenting foods for thousands of years. All equipment – chopping boards and knives, colanders, bowls, and the glass Kilner jars or ceramic fermenting ‘crocks’ – must be spotlessly clean but not sterile. Soap and hot water will do (a hot dishwasher cycle is fine).

3. Source veg carefully

“If you’re using really good fresh vegetables you’ll get more of the lacto bacteria that live on all living things grown in or on the ground,” says Katie. “Also, the vegetables will have higher water content and more nutrients. Vitamin C starts to decrease quite rapidly and that’s another advantage of fermentation – it arrests the decline of vitamin C.” Opting for organic is desirable but not essential. Just peel non-organic veg where possible and remember that veg such as sweetcorn or cabbage will have been protected whilst growing by outer leaves trimmed before you buy them.

4. Trust your senses

“One of the first challenges is the idea you’re working with living organisms,” says Katie. “Fermenting is much more like keeping a pet, or maybe having a Tamagotchi, than it is cooking.” We’ve become so reliant on fridges and freezers to preserve our foods we panic at the idea of leaving things to bubble away at room temperature. “But these foods are living and they need warmth,” says Katie. “We’ve forgotten to use our senses – smelling, looking, tasting. If something doesn’t taste nice, chuck it out. There are things that can go wrong – one of the golden rules is any mould that’s red, chuck the ferment out without any hesitation.” Other moulds and yeast that form are likely to be perfectly benign, so trust your nose.

5. Take your time

When is your ferment ready? Speedy Asian pickles can be ready in a few hours, but your sauerkraut will need daily checking for several weeks. “Depending on the temperature, it takes around five weeks for lacto bacteria to go through three or four cycles of fermentation,” says Katie. “Each cycle will promote slightly different bacteria, so the volume and diversity increase over time, to a maximum point at three to five weeks. You can make lots of delicious things quicker, but they’re not going to have the same nutritional value.” Give your jars plenty of ‘head room’ between the surface of the ferment and the top of the jar; that way, your ferments will sit happily as excess gasses escape through the rubber seal or airlock of your fermenting vessel.

Try this tonight

Simple sauerkraut

1. Select a fresh green cabbage, set aside a couple of outer leaves, and finely shred the rest into a large mixing bowl

2. Calculate two percent of the cabbage weight and use this figure to measure out fine non-iodised salt. (For example, if using 1kg of cabbage, you’ll need 20g of salt).

3. Roughly massage the salt through the cabbage, continuing until juices run from the shredded leaves.

4. Stir through a sprinkle of spice – caraway or fennel seeds are good – and then pack the mixture tightly into a clean Kilner jar, squeezing out any air bubbles.

5. Leaving around 5cm of head room at the top of the jar, use the set aside leaves to form a stopper that pushes the shredded cabbage under the juice.

6. Close the lid. If the shreds have sprung above the liquid, add half an apple to the top of the leaves to press the shreds down when the lid is shut.

7. Place the jar on a tray and leave in a cool spot out of the glare of direct sunlight.