A green-fingered ex-jeweller with a mission to revive Malta's olive oil production practically from scratch, Sam Cremona munches on a tiny black "Bidni" olive and shows it off to visitors. The olive, which has a distinctive pointed and curved stone, is an indigenous species packed with anti-oxidants that has been around for at least 2,000 years but had nearly become extinct before Cremona began his quest. "We lost the sense of it," said Cremona, who has acquired the deep tan of an outdoors labourer, as he prepared for this year's olive harvest on his farm some 40 kilometres (25 miles) north of the Maltese capital Valletta. "A lot of people thought that the Maltese olives would never produce good olive oil, because the oil was bitter," the 62-year-old said. "Today we realise the bitterness is one of the best qualities that Olive growing once flourished on this Mediterranean island under the Phoenicians and the Romans but it was rooted out when its Arab rulers pushed for cotton production and then its British overlords encouraged sheep rearing. The depopulation of Malta also helped the decline of olive farming. Many olive trees were torn out from the craggy Mediterranean landscape that seems ideal for olives -- and replaced with orange and almond trees. Cremona and his wife Mattie started the revival when they decided to plant olive trees around their large home in Wardija for household consumption. "When we had half a ton of olives, we said let's have them pressed but there was no olive press in Malta," Mattie Cremona said. They bought the machinery and set up a small press and friends and acquaintances flocked to them. "We realised there was really a need and a love for it," said Mattie, who has written three books on local recipes and history. Mattie said that Maltese olive oil is "extremely low in acidity" compared to others because of the type of soil and climate and also because the oil is pressed shortly after the olives are picked because the island is so small. "It's a quick transportation and a quick press," she said. Sam said the work which started out as a hobby had become back-breaking: "I hoped for a more sedentary, quieter life but this is going to kill me!" In between two cargoes of olives being sent off for pressing, Cremona welcomed a group of German tourists here to see his organic plantation. "I knew olive oil only from Italy, Greece and Spain but not from Malta. But I think it's very interesting. I think his work is very respectable!" said Ingeborg Minck, a 69-year-old tourist from Darmstadt in Germany. Tour guide Dagmar Pallmar, 56, said: "Olive oil is a kind of secret. It is in its infancy but Sammy is putting all his heart in it." Cremona's ambition is to revive production of the "Bidni" olive -- a word that means "hunchback" in Malta because of the shape of its stone -- to produce exclusive mono-variety olive oil that he believes would have global appeal. Wood from the native Maltese species was found in carbonized form in the nearby temples of Skorba dating back to between 3,600 and 2,500 BC. Cremona has called his project PRIMO -- Project for the Revival of the Indigenous Maltese Olive -- and uses cuttings from trees that are more than 2,000 years old and grafts onto other trees to spread the species. "The last five years, we've been grafting over a thousand trees, sometimes 2,000 trees a year. The aim is to have 10,000 of these trees and in this project I give these trees to people who are ready to put 50 or more," he said. Around 40 producers have taken part in PRIMO and 5,000 trees have been planted. Within the next two years, Cremona said he was hoping for European certification for "Bidni" olive oil which would make it more marketable. Cremona said research from Valletta University and from an agronomy institute in Bari in southern Italy had highlighted the qualities of "Bidni". He said olive fruit flies -- a common pest -- were not able to penetrate Bidni olives to lay their eggs "because they are full of antioxidants." "Bidni" olive oil could also boost the immune system and relieve high blood pressure, Cremona said. The mission is not over for Cremona, who in 2010 also found some trees on the island that produced white olives that turn slightly pink as they mature. Surprised, he did some research and found references in Renaissance texts to the "Pearls of Malta" offered by its rulers to European monarchs as gifts. This year he is planning to grow 100 white olive trees and he hopes their sweet-tasting oil will become another staple for global foodies.