What was the occasion?

I'm a health writer, and among other things, I have a strong belief in the health benefits of incorporating fermented foods into the diet. Fermentation increases the beneficial bacteria, vitamins and enzymes present in foods and makes the nutrients they contain more available for the body to use. It may not be a typical part of the diet in the UK, but a lot of countries have a history of fermenting food. I'm part of the Transition Network where I live in north London, and naturally a lot of our conversations focus on food. I got chatting to the people who run a local veg box scheme, and we decided to collaborate on an event that would teach people how to make ferments such as sauerkraut, as well as explaining the science behind it.

Fermenting ideas: Cabbage, cauliflower, onion, red peppers, carrots, turnips, ginger and celery. "We added sea salt and whey to the vegetables" ready to ferment Photograph: Michael Thomas Jones for the Guardian

What was on the menu?

Before we ate, I talked about common foods that you wouldn't think of as being fermented – chocolate, coffee and sourdough bread, for example, are all on the list. After the discussion, we ate a celeriac bake with tomato sauce and a green salad, which I served with a traditional Korean kimchee, sauerkraut and spicy fermented black turnips – it was a good backdrop to the discussion. We decided to get on with making the ferments before having pudding – we finely chopped about 17kg vegetables between 10 of us! For our ferment, we used cabbage, cauliflower, onion, red peppers, carrots, turnips, ginger and celery. We added sea salt and whey to the vegetables and took turns to press them down to release the water in which the fermentation would take place. It was then put into glass jars. After all the hard work we had pudding, which was sour cream ice-cream (again, a fermented food) with a cherry compote.

What did you talk about?

It was a really animated evening with lots of enthusiasm, questions and chat. I believe food is medicine and am passionate about combining that message with a way to get people making these wonderful foods, so I tried to answer as many queries as possible, from how prevent mould, how to slowly introduce ferments into your diet, and talking about the other positives, such as sustainability. I think everyone learned something new, and had lots of great feedback afterwards.

Spicy sauerkraut

The vegetable ingredients are flexible, and you can change according to taste as you do more batches. Weigh the total amount of vegetables in order to calculate the salt needed later.

Makes several jars

½ kg fresh white cabbage

½ cauliflower, cut into small pieces

2 carrots, grated

2 sticks of celery, finely chopped

1 onion, chopped

½ turnip, grated

2 garlic cloves, chopped

½ tbsp grated ginger

1 red chilli, deseeded and finely chopped

1½ tbsp good quality sea salt per 1kg of vegetables

1 Chop or grate the cabbage finely or coarsely to taste – if you prefer it to be crunchy, chop rather than grate. Mix all the vegetables together, and sprinkle in the sea salt.

2 Place the vegetables and salt in a wide-mouthed crock or clean plastic bucket. Tamp down with your fists or whatever is to hand that works to press hard to release the water in the vegetables. This can take up to 10 minutes, so be prepared to work on the floor for extra downward power.

3 Transfer to glass jars, then press down so that the vegetables are submerged in the water, and cover with a clean weight such as a plastic ziplock bag filled with brine (in case it leaks), or a glass jug or jar filled withwater. Finally cover with a cloth and put aside. Every now and then press down on the weight to make sure the sauerkraut is covered by brine.

4 Examine the kraut every day or so. If you have some mould on the surface this can be removed without fear of contamination. With time the taste gets stronger. After a week or so, taste, and when you get the flavour you like transfer to the fridge.

Traditional whole cabbage kimchi

Use fermented shrimp paste instead of fish sauce for a more pungent flavour.

2 small firm-headed Chinese cabbages, about 1.5kg

250g radish, julienned

1 small carrot, julienned

5 spring onions, cut into 5cm pieces

45g mustard leaves, cut into 5cm pieces

45g watercress cut into 5cm pieces

3 tbsp fresh kombu or half as much dry kombu, rehydrated

1 tbsp fresh ginger, peeled and crushed

2 tbsp crushed fresh garlic

60ml organic fish sauce or fermented shrimp paste

1 tsp red pepper powder

1 tsp chilli flakes

4-6 fresh oysters, chopped (optional)

For the brine

85g sea salt

2½ litres water

For the rice porridge

½ tbsp rice flour

190ml boiling water

1 Trim and discard any damaged leaves from the cabbage. Hold the cabbage upright and cut in half lengthwise from the top toward the root end, stopping halfway. Now hold firmly both ends of the cabbage and pull it apart.

2 Make the brine by dissolving the salt in the water, in a ceramic or metal container (metal is fine for brining, not for fermenting). Put the cabbage upright in the container. Make sure it's covered in the brine and let it soak for about 16 hours.

3 Rinse the cabbage thoroughly in cold water and drain well.

4 Mix the julienned vegetables with ½ tbsp of salt to wilt it (but rinse afterward).

5 To make the rice porridge, mix the rice flour with the boiling water. Cool for a while.

6 In a large mixing bowl, mix half the rice porridge (save the rest for later), fish sauce, red pepper powder, red chilli flakes, garlic and ginger. Mix with the wilted radish and the carrot. Add the spring onions, mustard leaves, watercress (and oysters if you are using them). Stir gently to mix.

7 Now take one of the cabbage halves. Lift up the leaves of the cabbage that are still attached to the core and push a little stuffing between the leaves, in a layering process. Do this with all the cabbage, using up all of the stuffing.

8 Now fold the leaves on the tip of the cabbage over the rest of the cabbage. Use two of the flexible outer leaves to wrap up the rest of the cabbage. Place the cabbage halves in a container (glass or ceramic) with the inner leaves facing up. Make sure the cabbage is covered by brine (make a light brine using 1 tbsp salt for 250ml water.

9 Ferment for 3 to 4 weeks in a cool place. You can taste it after 2 weeks to test its strength.

Baked celeriac in fresh tomato sauce with goat's cheese topping

Serves 4

1 celeriac, peeled and diced

Jar of passata

1 onion, chopped

2 garlic cloves, finely chopped

A small handful of fresh basil or oregano, chopped

Around 100g hard goat's cheese, grated

1 Steam the celeriac until partially cooked.

2 To make the tomato sauce, fry the onion and garlic in a little ghee or coconut milk, then add the passata and herbs then season to taste. Simmer for 20 minutes, or until the sauce thickens and becomes rich in flavour.

3 Add the celeriac to the tomato sauce and pour into a baking dish. Top with the goat's cheese then place in a medium oven for 30 minutes until the cheese is golden brown and the celeriac is fully cooked.

For further information, visit wiseuptohealth.com

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