Earth, fire, air, water: all the elements are at play when you’re building an oven from clay. It’s a tradition that dates back millennia. The ancient Egyptians used clay ovens, as did the Romans. In medieval Europe they were a feature of community life and in Italian homes today bakers still lovingly slide loaves into their fiery depths. Across Asia and the Middle East many people still cook with them.

Making an earth oven is a tactile, physical experience. You can’t help but marvel at nature’s bounty and the ingenuity of our ancestors when you’re eating food that’s been cooked in a vessel you’ve made with clay that you’ve dug from the earth. Then there’s the glorious feasting at the end, partaken with those who’ve laboured with you. A true communion.

Alas, the day I’ve come to River Cottage to have a go, it’s raining. This is no drizzle but a torrential, midsummer’s downpour. And clay and rain do not a good mix make; clay and rain make a squirmy mess. But very little fazes the folks here. The farm is set in beautiful countryside near Axminster, inland from the Jurassic Coast, on the Devon and Dorset border.

Its seasonal adventures have been well documented on TV and founder Hugh Fearnley-Whittingstall, the food campaigner and broadcaster, is today a household name. Animal welfare and sustainability are at the heart of everything that happens here. River Cottage supports small-scale, eco-friendly farming and growing and the making of artisan food, whilst aiming for zero carbon emissions.

You can take coastal hikes, cycle rides and courses in everything from foraging to beekeeping, all with a foodie focus. But I’m here for the Build and Bake day: a chance to connect with some good, clean Jurassic dirt. Slow food lovers and those drawn to traditional land-based crafts will warm to the setting, the ethos, the care and exuberance of the teachers and guides here. River Cottage has a social conscience and a heart: it has quietly created Landshare, which connects growers to people with (as the name suggests) land to share, and has founded a renewable energy community called Energyshare.

Its trainee cooks provide meals for a local charity that feeds the homeless. It’s impressive stuff, but it gets better. This is my first visit and the welcome is so infectiously warm and upbeat – positively joyous, in fact – that, rain or not, spirits are guaranteed to soar. I have little technical expertise, so when a four-page instruction manual had popped into my in-tray prior to my visit I’d been alarmed. Was I expected to do the job by myself, from scratch? Thankfully, not: building an earth oven here turns out to be a jolly and communal affair.

“Then there’s the glorious feasting at the end, partaken with those who’ve laboured with you. A true communion.”

Those of us who’ve signed up for the Build and Bake day assemble in the car park in a covered tractor trailer. Once we’re all aboard, it chunters down a steep lane and deposits us in front of River Cottage’s headquarters. The low-slung buildings manage to look both rustic and smart. Not so the soggy cows in the field beyond the glass-walled cookery school, which huddle mournfully under the trees trying in vain to stay dry. On a sunny summer’s day, however, I can imagine the views of the Devon countryside would be magnificent.

After reviving ourselves with teas, coffees and griddle cakes with local honey – they look after body and soul here – we don our waterproofs and head outside. Led by cheery tutor and earth oven aficionado Steven Lamb, we slosh our way to the pond through a muddy field brightened by purple thistle. On the water’s edge lies a rich seam of blue lias clay.

‘Your best sources are usually close to a pond, stream or small river,’ says Steven, digging a small hole in the clay on our behalf. We each reach down and get hold of a piece. It’s satisfyingly squidgy and supple. We roll it into a snake and wrap it round our fingers. ‘Good clay won’t snap,’ adds our guide.

The rain shows no sign of letting up, so on this occasion we’re not going to dig out the clay ourselves and lug it across the field. I’m a bit disappointed, as I’d looked forward to this part of the day and am feeling smugly rainproof in my gear, but I suspect I might be in the minority. Thankfully, River Cottage has buckets full of the stuff, ready and waiting for us. We trudge back indoors and after a fortifying cider brandy and more tea sipped round a fire in an enormous and cosy yurt – they get the little touches just right here – we start building our oven, with an awning for shelter. It’s wet, sticky teamwork.

Together, we create a dome-shaped sandcastle on a plinth. This is what’s known as a sand former and around it we’ll build the first layer of our oven. Ours is a large, scrupulously courteous group and everyone gets a turn to slap on the sand. When our sandcastle has been patted into a dome shape, we cover it with sheets of wet newspaper, papier-mâché style, and leave it to dry (a trifle optimistically). Once the clay oven has been built around it, we’ll scoop out the sand.

Next, our willing wellied feet get a workout as we gleefully stomp and twist on a tarpaulin filled with buckets of sand and clay. ‘The sand stops the clay from shrinking and cracking,’ says the multi-talented Steven, who also happens to be River Cottage’s meat-curing guru. Sand and clay, he tells us, are the oldest bulding materials known to man. One at a time we pick up orange-sized clumps of the stuff and whack it on the sand dome, creating the first ‘skin’ of our oven, brick by clay brick.

As we work we’re serenaded – not, alas, by birdsong, but by the steady (perhaps mocking?) patter of the rain. Leaving our clay to firm up, we head back into the kitchen for a lesson in bread and pizza making with master baker Joe Hunt. After all, a clay oven without food is a pleasure halved. Baking bread in such orderly (and dry) surroundings makes a striking contrast with the decidedly rustic nature of our oven-building. 51

“Our willing wellied feet get a workout as we gleefully stomp and twist on a tarpaulin filled with buckets of sand and clay.”

We each have our own station, apron, bowl and flour – very Bake Off – and with Joe’s guidance, we knead, shape and prove. He makes it look easy. Leaving our uncooked loaves to rise, we roll out dough for pizza bases and choose from a table laden with toppings: a roast tomato sauce, air-dried ham and nuggets of bacon, cheeses and rocket and basil, all of it farm produce.

I can’t pretend that this part of the day is anything other than a cookery class, but it is great fun. Our creations assembled, we take turns to dash out in the pouring rain to slide them into River Cottage’s own clay oven – a thing of beauty, with an inferno blazing at the back. It’s ferociously hot, even at a distance, and our pizzas are done in a minute, the crusts blistered and crisp.

Back in the kitchen, a long seating area by the windows has been laid out and we tuck in to our wood-fired treats. The taste is thrillingly smoky. Sipping juice, cider or wine we gaze wistfully out at the farm through the steamed-up glass windows. It’s not quite the sharing of food round a communal hearth, but with clear skies it could be.

After lunch, we shape our loaves some more before sliding them into the (indoor) ovens. At this point, I have to quell the urge to curl up in a ball by the yurt fire – though the option is there. Instead, I head back into the rain to fashion a chimney, and a rough-looking oven entrance, as well as slapping on another layer of clay.

Our oven now needs to dry before it gets an outer wall and it is at this point that we call it a day. The rain has thwarted us. There’s a silver lining though, with the smell of freshly cooked bread and hot drinks back indoors to distract us. Steven even invites us all to return, on the house, and do it all again in the sunshine. This is what’s known as a class act.