Reminiscing in the office of the synagogue building in Odessa, Rabbi Shlomo Baksht scrolls through the images on his phone in search of a photo of huge personal significance.

It depicts a confident young man in IDF uniform. His name is Natan and his life today could not be further removed from his early years in a Ukrainian state orphanage where children were routinely ill-treated.

In 1996, Natan became the first resident of a Tikva children’s home, an extension of a Jewish schools’ programme in the city which Rabbi Baksht established in 1994.

Since then, the Israel-born rabbi’s labour of love — he took out a personal loan on a small property to take in the first 30 boys — has transformed the lives of thousands of young Jews from abusive or impoverished backgrounds in Ukraine and former Soviet states through loving care and high quality religious and secular studies, from kindergarten to university age.

The initiative has also revitalised the Odessa Jewish community, as evidenced by the buzz permeating the synagogue, and provided a rich seam of new immigrants to Israel.

Travelling around Odessa, impressions are of a city of contrasting existence for its one million-plus inhabitants. Prosperous-looking residential and shopping districts and beaches which are packed in summer sit adjacent to areas of grinding poverty unimaginable in British terms, where life for the locals is often sustained by the consumption of prodigious amounts of cheap alcohol. Drug use and prostitution are rife.

“To see how people suffer, you have to come here in the cold,” says Tikva’s programmes manager Michael Brodman, who accompanies me to the home of Tatiana and her mother Katrina, literally a shack with two dank and dingy rooms occupied largely by beds. Shabby curtaining over the exposed entrances affords the barest protection against the brutal winter conditions. There is no running water and a hole in the ground in an outhouse serves as a toilet.

Katrina, who is 57, but with her ruddy features, looks considerably older, receives a small monthly pension. Tatiana, who cuts an agitated figure, says she works as a cleaner. Asked if she is happy that her two children are in Tikva’s care, she delivers a lengthy and expressive reply, which is translated simply as “yes”.

“It’s quite a good background,” Mr Brodman suggests as we return to the warmth of the car. “The kids did not suffer. They were not abused.”

He recalls that one mother arrived on the charity’s doorstep with her baby son, threatening: “If you don’t take him, I’ll throw him in the bin. I don’t want him.”

Others brought to Tikva by the charity’s search and rescue team have been living on the streets, in railway stations, in the basements of abandoned buildings, and even in sewers.

“Sometimes it’s harder to take a kid who has lived on the streets,” says Julia Shanina, Tikva’s director of development. “They have friends on the streets and it is hard for them to change.” Some cannot make the adjustment and return to their former lives.

The youngsters’ care and development “is a massive responsibility”, Rabbi Baksht acknowledges. “Children come from homes where they don’t know what normal is. They have to be taught so many things. It’s an enormous challenge.”

At the infants’ home — where the excitable occupants descend playfully on visitors — home head Chava Melamed becomes tearful as she recounts some of their histories.

“They like to get love from anyone new coming in,” she says. “They get a lot of love here but you cannot replicate the family. Some children we take from the hospital [maternity ward].”

Mr Brodman adds later that contact with parents is encouraged for those in its homes. “We believe a loving mother will always be one. Where parents don’t want to know, the kids are heartbroken.”

There are currently around 1,000 children and young people in the Tikva system — 100 new children are brought in by the rescue team each year. Some 300 live in the homes, sited in close proximity, with the schools within easy reach. At the boys’ home, PlayStation is king. Softer touches proliferate in the girls’ home, where residents demonstrate their musical and dancing abilities in a concert. Each home has an Israeli house family, affording the children a taste of regular family life.

The rescuers are led by Odessa-born Sasha, who left his own family home after being abused by his step-father. Returning to the city at 19, he resolved to support children from similar backgrounds by working in a state orphanage, serving both as a counsellor and music teacher while studying for a law degree.

After Rabbi Baksht arrived in the area in 1993, Sasha introduced himself, explaining the extent of the crisis of children in need within the Jewish community. He officially started work for the charity in 1995 and his expertise in accessing documentation is invaluable in confirming that Tikva entrants are halachically Jewish. “We don’t have the budget to take others,” Mr Brodman points out.

The charity receives no government support and relies on aid from overseas organisations to meet its $8 million annual costs. A key support group is Tikva UK, whose chief executive Karen Bodenstein says she becomes emotional “every time I visit and see the new faces and hear the stories of the lives they have left behind. But it also makes me more determined to do whatever we can to save the lives of as many Jewish children as possible.”

Although there are wealthy Odessa Jews among a community variously estimated as between 35,000 and 45,000 (with 4,000 actively involved), “we get really small amounts”, Mr Brodman notes. “The mentality of giving is something people here don’t get.” But the community does appreciate the value of learning and the schools are open to Jewish children from the city.

We drop in on a class at the girls’ elementary school as Lisa, nine, is asked in English by her teacher to discuss the weather. “The weather is bad,” she replies. “The wind is blowing. It is cold.”

Even in the kindergarten, children are playing educational games requiring a decent level of English comprehension. To the question from an educator: “The opposite of sad?” a boy scurries over to a selection of image cards, returning rapidly with the one depicting a smiley face.

In keeping with Tikva’s religious ethos (the boys all wear kippot), Ivrit is also taught, as well as Ukrainian, as the national language, and Russian, which is spoken widely in Odessa.

“English opens the ability to do everything,” Mr Brodman stresses. “We changed the teaching staff to have English speakers.”

In a city of high unemployment where basic monthly wages are $200 or less, he estimates that fluent English will get someone a job with a salary of at least $500. It is an important asset for those who remain in Odessa after their studies as they need to be able to provide for themselves, and ultimately, their families. And the 1,000-plus Tikva graduates now living in Israel are assisted by the charity’s development programme.

Many Tikva graduates return to teach. A case in point is Gavriel Viner, 37, director of Jewish studies at the boys’ school, who also heads Tikva’s Platinum Youth Club and other student projects.

One of a family of eight children, Mr Viner recalls that growing up in Odessa, “the food at home was bread and sugar. I never knew a Jewish life — what Pesach was, what matzah was. My friends were non-Jews.”

When he showed promise as a gymnast, his father implored him to pursue a sporting life. “He was afraid I would get called into the army. But in Odessa, if you are good at sport, you are safe.” So he attended a sports school — “but I did not study”.

He was 15 when he began attending Tikva, which had taught him “that I could be something else. A lot of friends from my past are now drug addicts and in prison. I don’t know what I would have done without Tikva.”

Because children come to the charity at different ages and with diverse abilities and problems, classes are by necessity small. Those with significant difficulties are supported at Tikva’s psychological centre, housed in an unprepossessing building away from the schools.

Some have development issues attributable to their mothers’ drinking or drug-taking during pregnancy. Others have been through psychological trauma. They can look half their age.

Those with the most complex issues attend the centre daily. These include children whose disruptive behaviour precludes them from Tikva’s mainstream classes.

Head psychologist Julia Tsapkalova says the initial target is to make a child feel safe.

“It’s hard when someone is abandoned. The first thing the child thinks is that he is the bad one. He stops trusting the people around him. Part of the work is getting them to trust adults again. It is very individual.

“If, beyond the trauma, the child has brain damage, it’s more difficult.

“Every child needs a mother or father,” she adds. “Someone they can rely on. Even if the mother was horrible, they still love her.” Ms Tsapkalova explains that when a child’s demeanour becomes calmer, “the brain works differently — even how they walk.

“The second goal is to give them the skills and abilities to live alone and earn money. We also work with students and with parents to teach them how to deal properly with kids.”

In the late 1800s, Odessa boasted Europe’s second largest Jewish population after Warsaw. The wartime massacre of Jews, when the city was under Romanian control, and post-war antisemitism decimated Jewish life.

Tikva’s arrival has heralded a renaissance. Rabbi Baksht also holds the title of Odessa Chief Rabbi and the organisation is involved in clubs for the elderly, meals on wheels and other welfare work, a kosher restaurant and a kosher shop offering products ranging from Oreo cereal to caviar.

“I came to Odessa for one year,” he reflects. “Twenty-six years on, every year has a new surprise.”

In taking Tikva forward, Rabbi Baksht has sacrificed his own family life — his children and grandchildren live in Israel. “But a person needs to do what is right, not what is comfortable.The best nachas is seeing how they come out of Tikva. It’s my family and it gives me enormous joy. Everything is worth it.

“You can see in the synagogue there’s life, there’s learning, the community is alive.” And indicating the sounds of prayer and study emanating from the adjoining room, he declares contentedly: “For me this is the best music.”