Bernie Sanders takes the oath of office to become the mayor of Vermont's largest city, Burlington, on April 6, 1981, two decades after he spent time on an Israeli kibbutz. (Donna Light/AP)

— The residents of this crunchy Israeli farming commune, with its milk cows and solar panels and lefty vibe, were both pleased and surprised to hear their home may be the “mystery kibbutz” where presidential contender Bernie Sanders spent a few formative months in the 1960s.

The old-timers confessed Sunday that they didn’t remember Sanders. It was a long time ago. The senator from Vermont isn’t talking. And the kibbutz archives have yet to reveal any evidence that Sanders was a volunteer here, said Yair Merom, chairman of the community, who nevertheless did interviews with Israeli radio and TV after news broke that this might be Sanders’s former kibbutz.

“There was a Bernard,” recalled Albert Ely, 79, who used the French pronunciation of the name. Ely was just sitting down to a heaping plate of rice and beans in the kibbutz cafeteria. “But I don’t know if he was the famous Bernie from America.”

Ely arrived at the Shaar Haamakim kibbutz in 1957, fresh off the boat from Egypt. He said record-keeping in the old days was spotty. Volunteers from Europe and the United States came and went, brought to the farming community by Jewish youth movements.

“They picked pears,” Ely said.

The volunteers slept in cabins, ate their breakfasts in the orchards, did menial labor.

And they lived socialism — the dream and the reality.

[Why Bernie Sanders doesn’t participate in organized religion]

In the heady days of the 1960s, the Israeli kibbutzim were an accessible laboratory to observe social democracy in action — where children, even babies, were raised communally in nurseries and dormitories away from their parents, where work and reward were shared, and where momentous decisions about who went to college or who mucked the barn were made by the group, not individuals.

Journalists have been on a hunt in recent weeks trying to solve the mystery of which kibbutz Sanders visited. There were tantalizing clues, good guesses, dead ends. Was the kibbutz near the sea? Were there Argentine volunteers? Was it Marxist or Labor?

Sanders and his campaign staff have repeatedly — and somewhat inexplicably — declined to say which kibbutz.

Then on Thursday, the Israeli columnist Yossi Melman dug up an article he had written in 1990 for the daily Haaretz. In the piece, headlined “The First Socialist,” about his first campaign for the Senate, Sanders told Melman that in 1963 he spent time at Shaar Haamakim as a guest of the Young Guard, a socialist Zionist youth movement called Hashomer Hatzair in Hebrew.

Mystery solved, the news media trumpeted.

[The kibbutz Bernie Sanders stayed in may have been revealed]

‘A very political thinker’

Larry Sanders, Bernie’s brother, isn’t so sure.

When he heard the name Shaar Haamakim, “it didn’t ring a bell,” he said in a telephone interview.

He emphasized it was a long time ago — more than 50 years. But of one thing he was certain: The date of the visit was later than 1963.

Bernie Sanders and his first wife, Deborah Shiling of Baltimore, were married after Sanders graduated from the University of Chicago, in September 1964, Larry said, and their visit to Israel was “part of their honeymoon tour.”

The newlyweds visited Larry Sanders in England that fall and stayed in London, where Bernie Sanders, “a convinced socialist at that point, and learning a lot,” followed the British elections, which the Labour Party won that October. Larry also remembered his brother's interest in Britain’s system of socialized medicine, the National Health Service.

“He was a very political thinker already,” said Larry Sanders, who is almost seven years older than his brother and has lived in England since the late ’60s, where he is a Green Party member and former county councilor.

The young couple went from England to Israel, probably making other stops on the way, and would have arrived, Larry Sanders estimated, in late 1964 or early 1965 and spent about three months or so at the kibbutz.

It was a formative time for Bernie, his brother said. Larry Sanders also stayed in Israel — but on a different kibbutz.

Bernie, he said, met and talked with other volunteers, several from Argentina who used to speculate whether a similar rural agrarian system might work on a larger scale in South America if they were to live through Che Guevara-scale change.

“Those kinds of conversations,” Larry Sanders said. “He was thinking not only about the day-to-day but the larger socioeconomic kind of viewpoint.

“He was interested in daily life and in the big picture. That was very important to him.”

Larry Sanders doesn’t look back on their visits to kibbutzim as Zionist acts. Although staying at kibbutzim became more popular after Israel’s victory in the 1967 war, it wasn’t uncommon, he said.

“Most were not planning to stay; in that sense they weren’t Zionists,” he said. And a kibbutz was “an easy place” to visit for young people traveling overseas for several months without a lot of money.

As for the other person who could solve the kibbutz mystery? Sanders’s first wife, Deborah Shiling, lives in Vermont. “They remain good friends,” Larry Sanders said. But, he warned, “she is very protective of her own privacy.”

The Washington Post had a brief conservation with Sanders’s former wife, now Deborah Messing, on Sunday.

“It’s already been published,” she said.

Asked to verify that Shaar Haamakim was the correct name, she hesitated.

“I don’t know,” Messing said. “I can’t think.”

Communal living

The residents of the kibbutz, whose name translates as the Gate of the Valleys, are not trying to claim Bernie Sanders as one of their own.

These are mellow old socialists, happy to admit past mistakes, but proud of their accomplishments and the role the kibbutzim played in the founding of Israel.

Several members suggested it didn’t really matter which kibbutz Sanders visited in 1963 or 1965. What was revealing and important is that he visited one.

The Shaar Haamakim kibbutz was founded in 1935 by Jewish immigrants from Romania and Yugoslavia and was affiliated with Mapam, a left-wing, pro-Soviet workers’ party — but not Marxists. About 700 people live in the commune, which grows wheat and fruit but is best known for its solar-powered water heaters, which ship internationally.

“It was different back in the old days; it was true socialism,” said Amalia Alva, who arrived in 1971. “Everything was shared.”

There was a gas station, but no one owned the gasoline. Cars and tractors were communal property. Housing was distributed by need or seniority. Children were raised by the village.

“Now, looking back, it’s funny how we lived. Babies being raised in the children’s house. I don’t want to go back, but we look back with respect,” said Yoki Zuk, a sculptor, who was born on the kibbutz in 1946.

The members were Jewish and Zionist, but decidedly secular. They celebrated the holidays, but in their own way. There were no rabbis and little traditional prayer. “We got rid of religion,” Alva said. “We didn’t care if people believed or not.”

“We were young. We liked the work, we liked the life,” said David Sivan, 80, who tended the fields in the 1960s and would have worked beside Bernie Sanders if Sanders had been there, but says the name doesn’t ring a bell.

Ely, who doesn’t remember Sanders, either, said that the kibbutzniks like what they hear about this famous foreigner.

“I will be very happy if he is elected president,” Ely said. “Not because he visited here, but because of his ideas.”

Sellers reported from Washington. Ruth Eglash in Israel and Michelle Boorstein in Washington contributed to this report.