Watch: How to get started in the bubbly world of fermented food and drink

“It’s a very natural process,” says Linda O’Flynn, of Cork-based wild fermentation company Terra Ignis. “I try to dispel the myth that it is difficult. We’ve been doing it for thousands of years.”

We may look to probiotic-rich, lacto-fermented foods from other cultures — Germany’s sauerkraut and Korea’s kimchi — for inspiration, but there’s also a strong fermentation tradition in Ireland, including dairy, stout, whiskey, and oats and potatoes.

Fermented potato has come to restaurant plates and public attention in recent years, with Donegal chef Ciaran Sweeney adding a deliciously chewy, fermented potato bread to the menu at Dublin’s Forest & Marcy and now as head chef in Donegal’s The Old Glen Bar and Restaurant. Memories of his grandmother’s baking inspired him. Growing up on a dairy farm in North Cork, O’Flynn’s grandmother soaked potatoes overnight in salty water for the next day’s meal, a short ferment that helps to break down starches. “When I first encountered fermentation, in my 20s,” she says, “I thought, ‘I’ve seen this before.’”

Working with seasonal, foraged ingredients and wild yeasts, O’Flynn is focused on developing an Irish fermentation culture. “If a food is digestible, it’s fermentable. I like looking at the Irish landscape and seeing what ferments we can make using those [foraged] plants. I like to experiment by putting things together and seeing what happens.

“When you work with wild fermentation, no two batches are the same.”

O’Flynn, who runs fermentation workshops, some involving foraging and fermentation, is adept at teaching beginners how to take the first steps in their home kitchens. For her, kombucha, sauerkraut and tepache — aka fermented tea, fermented cabbage and a fermented pineapple drink — are the gateways into this bubbly, funky world. Most importantly, it’s not expensive.

If you’re starting out, O’Flynn recommends you stick with a basic kit: jars, scales, muslin, which she picks up at Guineys in Cork, and rubber bands.

“You can ferment anything in jars. Keep your [large] pickle jars and reuse them,” she says. “You need a scales — weighing things is an important part of [fermentation] and, if you’re making something like kombucha, you will need to cover it with a piece of muslin —or a cotton serviette, as long as it’s breathable — to let oxygen in while stopping flies and other critters getting into it. The rubber bands secure the muslin on top of the jar.” It’s also about keeping ingredients simple, while being aware of potential downfalls, particularly with water and salt. Most mains tap water is chlorinated to kill off bacteria, which means it will also kill the good bacteria you need for fermentation. “You need good unchlorinated water,” notes O’Flynn.

“You can use filtered water, but bottled water is probably the easiest.”

Also, avoid free-flowing table salt, which may contain anti-caking agents and iodine, inhibiting good bacteria growth. “Use non-iodised salt. It needs not to be iodised,” says O’Flynn. “If you’re using sugar, get the best organic cane sugar you can find.”

For kombucha, you will also need tea — O’Flynn recommends an organic black tea — and a scoby, a symbiotic culture of bacteria and yeast.

The scoby looks like a rubbery disc and, when added to the sweetened black or green tea, it floats to the top, fermenting the liquid into kombucha over the next 10 days. The scoby creates a new layer with each batch brewed, so if you have friends making kombucha, they will have an abundance of scobys to share.

O’Flynn sells scobys at the English Market’s Terra Ignis stall, through her workshops, and it’s also easy to buy starter kits online.

Once you get used to having something live and bubbly in the corner of your kitchen, there’s a whole world of fermentation to play in.

“We normally think of anything that is bubbling as a bad thing, showing that it’s gone off. But, actually, with fermentation, it shows that it’s in a safe space and it’s a good sign,” says O’Flynn.

While it can be expensive to buy fermented products that use quality ingredients, O’Flynn points out that doing it at home doesn’t have to cost a lot. “It’s so cheap to make a jar of sauerkraut. A head of cabbage costs a euro; then you just need salt and a jar. It does require a little minding and interaction, but, from a financial point of view, it’s very cheap and accessible. It cuts down on food waste, too.

“Once you understand the principles, you’ll see that we can have living foods in our kitchen cheaply and easily,” she adds.

“Everyone should have access to fermented foods, in terms of their health, and it’s something everyone should be able to do for themselves.

• For more information on Linda O’Flynn’s upcoming fermentation workshops — at L’Atitude 51 in Cork, Seagull Bakery in Tramore, and Two Green Shoots in Glengarriff — check out terraignis.ie