In the valleys of Patagonia, the talk is of an astonishing revival of the Welsh language

In a red-brick farmhouse in the Patagonian village of Gaiman, Eluned Gonzalez is making jam, and masses of it. As her tiny home-help, a native woman with a long pigtail, sweeps the floor aimlessly, Eluned and her family prepare a multitude of jars that will store enough preserves for many winters.

It is a quintessentially Welsh scene, and as the vats of fruit bubble, the conversation flows in Welsh, the language in which Eluned and her sister Tegai were brought up, and which her son, Fabio, 30, also speaks fluently. Many people of Eluned's generation in Gaiman village speak Welsh, which took root in this distant corner of Argentina, more than 1,200 miles from Buenos Aires, after a group of Welsh colonists arrived in 1865.

Welsh speakers of Fabio's age are much rarer, but not as unusual as they were because, without fanfare, a Welsh revival has taken hold in Patagonia. Over the past decade, hundreds of local people have re-learned the language their parents and grandparents spurned to fit in with Juan Peron's Latin Argentina.

"It was in decline until 1965," says Professor Fernando Coronato, of the Patagonian Institute in Puerto Madryn, the port where the settlers landed. "But the centenary celebrations started a revival and since then it's grown."

The professor is living proof of his own words. With not a drop of Welsh blood in his veins, he speaks with a fluency that would shame much of Cardiff, as does his colleague, Marcello. The revival has touched men such as David Williams, a fresh-faced doctor in his early 30s. He has Welsh blood on both sides but grew up knowing only Spanish. "There used to be a kind of shame about Welsh," he said. "The Welsh were teased for talking differently so my parents did not speak it."

But he feels no shame, and learned Welsh two years ago. After his first child was born 14 months ago he proudly named him Eric Thomas, in homage to the distant mother country.

Welsh language and culture flourished in the Chubut valley of Patagonia until the First World War. The colonists dotted the valley, which they named the Gwladfa ("the colony") with chapels that reminded them of the ones at home, named Seion, Moriah, Bethel or Nazareth. Their rural settlements, Trelew, Bryn Crwn and Dolavon, recall their dream of creating a new Wales in South America.

But the dream crumbled after the war. The Argentinian government increased pressure on them to assimilate into the Spanish-speaking mainstream and flooded the valley with Spanish and Italian immigrants. As people increasingly "married out", they forgot their roots.

The centenary celebrations in 1965 led to a modest revival but the fashion for all things Welsh took off only in the late 1990s, after the British Council and the new Welsh Assembly set up a scheme to send Welsh teachers to Patagonia. The interest they won galvanised Sara Lewis, of Aberdare, who is now working in Gaiman with the project. "One couple I teach has no Welsh roots at all," she says. "He is Australian and she is Argentinian but they feel learning Welsh makes them part of the community."

Her colleague Nesta Davies, working 400 miles west in Trevelin, has been equally impressed. "I just marvel at how the language survived here for generations," she says.

The Chubu valley's Welsh minister, Mair Davies, says the teachers have worked a minor miracle. "They've done such a great job," she says. "If it wasn't for them, my generation would be the last to speak Welsh. As things are, hopefully, it will go on."

But Professor Coronato warns against false hopes that the fad for attending Welsh classes and eating torta galesa ("Welsh cakes") will restore Welsh culture to the place it occupied in Patagonia 80 years ago. "It will never be the language of the streets again," he said. "What we are seeing is a search for identity." This is a point Ms Davies, at Trelew's Tabernacle chapel, endorses. "The new Welsh speakers don't come to the chapel," she says.

With Spanish names and backgrounds, the new Celts belong to a different world from that in which Eluned Gonzalez and her sisters were raised. In their youth, Welsh was the language of hearth and home, honed by daily prayers and weekly sermons. When I went to Gaiman's Bethel chapel on a Sunday, the congregation was no more than 40, and most were elderly.

Now the keepers of the Welsh flame in Patagonia fear the Welsh Assembly will pull the plug on the teachers' scheme, just as it has borne fruit. Interest in Welsh shown by the Assembly's English-speaking Labour majority is fitful and there are doubts whether the two teachers now in Patagonia will be replaced.

"Without help from Wales, it won't survive," says Elvey Macdonald, who took part in setting up the project. With only about 2,000 speakers left in Patagonia, he says, the number is too small to be self-sustaining.

But like many Welsh Patagonians, he is proud this little sliver of the Celtic people has held out for so long, and so far from home. "I remember a man from the BBC coming to Patagonia and saying it would all be dead within 30 years," he said. "That was more than 50 years ago."