It started as an obsession with his grandmother's romantic teenage years in pre-revolutionary Russia. But it grew into a desire to make good on his great-grandfather's pledge to do right by the village where he lived and prospered.

Documentary-maker Dan Edelstyn has revived the vodka business his family once owned to breathe new life into a down-at-heel Ukrainian village, and at the same time discover his own roots.

"When I found my grandmother's diaries in the attic four years ago, I became fascinated by the fact she belonged to a hugely wealthy Russian family, yet ended her days penniless in Belfast," explains the 34-year-old director, who lives in London's East End.

Maroussia Zorokovich, his paternal grandmother, was born in 1898 into an aristocratic Jewish family. Her father owned the vodka distillery and sugar factory which brought prosperity to the people of Douboviazovka. "My great-grandfather brought the telegraph and the railway to the village and opened a war hospital; it was all part of that Jewish ethic of doing good," says Edelstyn.

After the Communist revolution ,Maroussia and her husband fled to Antwerp, where he worked in the jute industry. "Eventually, he was offered a job running a jute factory in Belfast, where they arrived in 1933," says Edelstyn. "My grandfather started a scrap metal business, did a lot of business with the Protestant elite and became a Mason. But it was a very polarised society, and my grandmother sympathised with the Republican cause. She converted to Catholicism, was denounced by the rabbi as an evil woman, and ended up in an unmarked grave in the Falls Road." The conversion was to rebound on her descendants for generations to come.

Says Edelstyn: "My grandfather felt he could not place a headstone for her, and my father, who was 13 when Maroussia died, decided not to go ahead with his barmitzvah. They were cast adrift by what happened, though they are buried side by side in the Jewish cemetery in Belfast."

As for Edelstyn, who inherited their name but lost his halachic link when his father married out, he has been haunted by a sense of not being Jewish enough. "I had a sense of belonging and a desire to explore my roots. However, that wasn't good enough for many of the Jewish charities who quizzed me about my background when I sought funding to return to the Ukraine and see if the factory was still there."

His pedigree as a prize-winning film-maker - he has made several programmes for Channel 4 - was good enough, however, for the Shoresh Foundation and JFS Pollitzer Charitable Trust, who joined with Scottish Screen and the Commonwealth Broadcasting Association to fund a documentary about his quest.

The work that has resulted from his trip to Ukraine is currently appearing in short episodes on the online video platform Babelgum, and More4 have bought the rights to broadcast it when it is completed.

Edelstyn, who travelled to the Ukraine with his wife Hilary, had a moment of epiphany upon arrival in Douboviazovka. "We met a 103-year-old woman called Natalia who had known my grandmother. She told me she had dreamed I would come and ask about the Zorokoviches. What had started as a ruse for a film led to a sudden feeling of belonging - it didn't take much to give me a sense that there must be some purpose to my being there."

When Edelstyn discovered that the distillery his great-grandfather had owned was still functioning under state ownership, a glimmer of a business idea took shape. "I wondered if I could somehow connect this village with the lucrative international market for vodka and at the same time honour my ancestors' memory."

The answer, he felt, was to create a new Zorokovich brand which the state-controlled distillery would produce, and it would donate a portion of profits to the local people. "I have gone through various ideas about how to give back to the village, and the principal way is to stimulate the economy and create jobs in order to build up in better healthcare, schools and sanitation."

With the help of £30,000 - funds from his mother's savings and from an investor - the vodka went into production and will go on sale in London next month.

Edelstyn says he has assuaged the feeling of being dispossessed of his heritage. "I feel like I belong now I'm doing something useful in the place my ancestors came from. It brings the past into the present, with a link to the future."

All he wants to do now is complete the project that started it all. "It's been beg, borrow or steal all the way along but I still need to raise money to finish my film."