Where will you find the best olive oil in Ireland?

"If you see Jamie Oliver cooking [Italian food] on telly, he will have a bottle of Fontodi to hand." David Gleave, Master of Wine and MD of Liberty Wines, was in Dublin to give a masterclass in olive oil on Tuesday, and the Tuscan oil favoured by Oliver – who uses it in his restaurants – was one of a selection that he presented for a tutored tasting.

“Look for the vintage on the bottle, that’s a key thing; the younger the better,” says Gleave, introducing the new 2016 vintages from his company’s portfolio, now on sale in selected wine shops and specialist food shops here and in the UK.

Six little cups of olive oil, ranging in colour from mellow gold to bright green, and crystal clear to cloudy, await the tasting panel in Jamie's Italian in Dundrum. No bread is on offer – that's a definite no no as the flavours in the bread could mask those in the oils.

Swirl and sniff

Gleave gives his class quite specific instructions to warm the oil by cradling it in their palm, before topping the container with the other hand and swirling enthusiastically, and then sniffing it and finally tasting it.

These are single estate oils, intended to be used as finishing oils, to be drizzled over things rather than cooked with, and they are each very different in taste and appearance. But they have two things in common – they are produced by winemakers, and they have hefty price tags attached.

“Where there isn’t a vine planted on the farms, there’ll be an olive tree,” says Gleave, explaining where wine and olive oil intersect in his business. The recommended retail prices for the boutique selection of oils his company offers range from €15.99 for 50mls of the Fontodi, to €28.99 for Capezzana and Petrolo, two of the other organic offerings, in 75ml bottles.

Single estate

So, what makes these extra special, single estate olive oils worth the investment? They are incredibly delicious and vibrant, possessing a range of expressions of flavour that is unique to each, and will change subtly in the bottle over time – until the next new harvest comes around. And, in an industry beset by scandal and fraud, you can be sure of what you are getting. “A pretty dirty business”, is how Gleave describes the olive oil trade.

Despite the high prices, the winemakers say they don't make money out of olive oil, Gleave says, as production costs are high and yields are low. "From each tree in Tuscany, you'll probably get less than a litre of oil," he says.

But making really good olive oil is a source of great pride for the winemakers, according to Gleave. "They'll say yes, we make good Chianti, there's lots of good producers, but no one makes better olive oil than us, and no one makes better Vin Santo than us. Those are the two things that are incredibly individual to each estate."

Irish producers

Making olive oil is undoubtedly hard work, compounded by challenging weather conditions and environmental factors such as plant pests, including the olive oil fly. But still, that pride is shared by most who set out to do it and do it well – and that includes some Irish-based producers who each winter return to their roots, or their holiday homes, to make olive oil and bring it back to sell here.

Lino Olivieri spends part of each year on his family farm in the Gargano National Park in Puglia, where he runs an agritourismo business in summer and makes olive oil in winter. Back in Dublin, he sells the oil at markets and through specialist food shops, and ships it nationwide. See olivierioliveoil.com.

Architect and lecturer Maria Achtida returns to Greece several times a year to cultivate the olive trees on her grandfather's farm in Messologhi and make oil which she ships back to Dalkey to be bottled and sold in local food shops. She also sells her 220 Trees oil – named after the number of trees in her care – online at 220trees. com.

Restaurateur Mark Shannon makes excellent olive oil from the trees at his holiday home in San Gennaro, near Lucca, but to taste it you'll have to book a table at his family business, Bistro One in Foxrock, where it is on the tables ... as long as stocks last.

“We think we’ve enough to get us to July this year,” says Shannon, who believes his 2016 oil is the best he has ever made, although his yield was down 50 per cent on 2015. See www.bistro-one.ie.

As part of its 25th anniversary celebrations last year, Kilkenny’s Ristorante Rinuccini launched its own extra virgin olive oil for sale to customers. It was sourced from a family-owned estate in head chef and owner Antonio Cavaliere’s native Lazio. See rinucinni.com

Stockists

The Liberty Wines olive oil collection is now available in selected wine shops and specialist food stores including Jamie's Italian, Dundrum; 64 Wine, Glasthule; Ballymaloe Cookery Shop, Co Cork; Jus De Vine, Portmarnock; Green Man Wines, Dublin 2; Fallon & Byrne, Dublin 2; Lotts & Co, Dublin 4; Terroirs, Dublin 4; Red Island Wine, Skerries, and Thomas's of Foxrock.