Heard the one about Irish wine? Like its English counterpart, it is no longer a joke, with more than a dozen vineyards now producing bottles to emulate those of the terroirs of France, Spain and Italy.

At about €60 (£50) a bottle and produced in small quantities, it is far from a commercial activity, but efforts over the last 10 years have produced what one retailer described as an “arguably very fine” rosé.

Global heating is pushing the viability of grape ripening northwards, says Kees van Leeuwen, a viticulture professor at Bordeaux University and co-author of a paper on the climate crisis and wine production.

And Paul Moore, a climatologist who works for the Irish meteorological service, says conditions for growing crops have become “more favourable” in Ireland in the last 30 years.

Research comparing the 30 years between 1961 and 1990 and the period from 1991 to 2020 show days getting warmer and nights even more so, reducing the prospect of late frosts that damage buds and roots.

“The mean temperature overall for Ireland has increased by 0.7 of a degree Celsius,” Moore said, while rainfall has increased by 7% over the same period. The growing season has increased overall by seven to 16 days.

Vine growing in Ireland is still a major struggle and the increase in temperature and addition of extra growing days do not change conditions significantly enough to grow classic crops such as chardonnay.

One of the longest-established wine producers is David Llewellyn, who has been growing grapes for decades on his fruit farm in Lusk, less than half an hour north of Dublin. He says the key factor was finding the right root stock and grape variety for cool and wet climates.

White varieties such as solaris and red varieties such as rondo have been grown as far north as Sweden and Finland.

“In my experience of 30 to 40 years of growing grapes in Ireland, there are only a handful that have proven themselves,” Llewellyn said. “We kind of stumbled along, making lots of terrible mistakes, innocently planting the wrong varieties that wouldn’t have a snowball’s chance in hell of ripening in Ireland. Even experts in France have no idea how marginal the Irish climate is.”

Better known for his cider, vinegars and fruit juices, he now produces about 150 cases a year of his Lusca sparkling rosé and a red wine, selling to restaurants.

“It’s a kind of side hustle that’s grown into a sideline and is becoming a more significant part of my sales,” he said.

The two main varieties he grows are a white grape, madeleine angevine, grown in Germany, Kyrgyzstan and Washington state, which has a similar climate to Ireland, and rondo, a black fungus-resistant hybrid grape bred in 1964 in the then Czechoslovakia and first planted commercially by Thomas Walk Vineyards in Ireland.

Described on the vineyard’s website as “full bodied” with a “fruity hint of black cherries”, rondo’s winning characteristic for Irish growers is that it buds and ripens early, giving it a chance of ripening over temperate summers.

“The problem is getting them to flower in the first place,” Llewellyn said. “To get an idea of just how marginal the Irish climate is for growers, a classic bordeaux harvest would take 100 days from flowering to harvest, compared to 150-day cultivation period in Ireland.”

Seán Gilley, of Terroirs, a specialist wine importer in Dublin, said a “superb margaux” could be bought for the same price as a bottle of lusca.

He said Llewellyn’s early efforts “were a mixture of success and failure” but that Llewellyn’s “passion for his vines” and produce were now producing wines of “much better quality”, especially his sparkling blanc de noir with hints of rose petals. “It is arguably very fine,” he said.

Farther south, in Kilkenny, Philip Little and Séan Kerin are just as passionate, though they haven’t marketed any wine yet.

“Our aim is to have a bit of fun and to produce wines that people will enjoy,” said Kerin, an Australian. But he admitted: “Nobody will retire rich on Irish wine.”

Still, he said, if England, which now has hundreds of vineyards, took 50 years to work out the right varieties for the climate, then he and other vine growers in Ireland are the “pioneers” who are “working out what works and what doesn’t for a future generation”.

With a six-year-old vineyard, they have yet to produce commercial quantities, turning in about 1,500 bottles a year.

A qualified viticulturist of Irish heritage, Kerin worked in the pinot noir fields of the Koolong estate in Mornington peninsula south of Melbourne and in the northern Rhône wine region in France.

He urged customers not to dismiss Irish wine as a joke. “Taste what is in the bottle first. If you think of what people said about English wine 50 years ago or even less, they would have the same thing as they are saying about Irish wine,” he said. “I would say to people just keep an open mind and try it.”