In her television studio in El Segundo, Roseanne Barr is singing the Israeli national anthem – and it’s good.

“If I asked you to sing ‘Hatikvah,’ would you slug me?” I had hesitantly asked her, remembering her screeching mangling of “The Star-Spangled Banner” before a baseball game in 1990.

Roseanne responded with a look of genuine shock. Of course she would sing it, she said, even though, she added, “I haven’t practiced it and I do forget a lot of the words.” But then she began crooning the Hebrew in a rich, vibrating alto, carefully pausing before the high notes, crescendoing to a heartfelt peak – before stopping midsong. “The rest is really hard,” she explained. “The only songs I can sing really good are the Hebrew songs of my childhood.”

Even so, Roseanne, at 58, comes off more like a Jewish wise woman than the sardonic “domestic goddess” who transformed her blue-collar feminist comedy into a hit sitcom, “Roseanne,” from 1988 to 1997. Now a grandmother of five, she’s wearing her salt-and-pepper hair long, stylish red glasses and little makeup. And even after leaving Los Angeles for a simpler life in Hawaii, she has continued mouthing off on her blog, RoseanneWorld.com, as well as in a 2011 memoir, “Roseannearchy: Dispatches From the Nut Farm,” which describes her Jewish journey amid rants about politics and her ex-husband, Tom Arnold (the book appears in paperback Oct. 11).

Roseanne’s adventures on a macadamia nut farm in Hawaii are chronicled in her new reality series, “Roseanne’s Nuts,” which premiered on Lifetime July 13. The show may touch on her plans to once again publicly sing the American national anthem, this time, she said, triumphantly.

Roseanne has been practicing her singing, which has also improved courtesy of the breathing techniques she’s learned since becoming one of the first celebrities to frequent the controversial Kabbalah Centre in Los Angeles in the 1990s.

“So many people in Hollywood go, like, ‘You’re such a Jewy Jew,’ ” she said, laughing.  “But I think it’s just fantastic to be a Jewish person. Jews are such a fantastic bunch – thinkers, creators, moralists – and the more people know that about us, the better.”

Roseanne traces the rage and fear that has fueled her comedy to growing up in a Jewish family profoundly scarred by the Holocaust, in predominantly Mormon Utah. “It was all exile, all the time,” she said.

While her feminist stance began courtesy of her two strong but very different bubbes, she was disgusted by the sexism in her family. “Because I was the oldest girl, I was always the slave, and I had to serve,” she said with distaste. “It was so much about class,” she added. Barr’s more affluent cousin, Debbie, got to search for the afikomen every Passover while Roseanne did the dishes.

“Debbie had dimples and light hair, a waist and a butt – all the things I didn’t have, which is why I hate her,” she said. “I shouldn’t say hate,” she added, sheepishly. “But I had been the Shirley Temple of the family, performing on every Shabbos, until Debbie came along and made me a has-been at 6.

“And then Debbie and her brother, David, got a Dr. Ross Dog Food commercial that was actually on television, and I was just burning alive with envy and at the injustice of everything, which has made me who I am. My comedy was always so full of all the negative emotions. But once you make a joke, it helps dissipate all that stuff, and you can become human again.”

Jewish practice has also helped mellow Roseanne; the change came when her friend, actress Sandra Bernhard, introduced her to the Kabbalah Centre.

Barr has described the transformation in a stand-up routine about how she felt driven to tear her ex’s hair transplant plugs out by the roots. “I was like, ‘Man, I almost killed a human being. I’d better give some money to, like, f–ing crippled children or something,” she said. “And my rabbi goes, ‘Well, Roseanne, those are real nice ideas, but I think probably the best thing for you to do is just try to be nice.’ I thought, how hard can that be? I didn’t know it was going to be like a walk through hell.”

She told me: “After years of trying to gag down all that ‘nice’ crap, the rav [said] I had totally misjudged his advice. He said, ‘You can be the meanest person on earth; that’s how you’re made. It’s your target that matters.’ So there’s a new paradigm for me to be angry at the right things, which actually are the wrong things [in the world].”

She’s generated controversy for some of her shock tactics, such as the time she appeared in Heeb magazine dressed as Hitler, removing burned, people-shaped cookies from an oven. She claims the cookies were meant to represent Palestinians in Israel.

Barr once called for a “10 million bitches march” on Washington, D.C., to challenge Sarah Palin.

“It infuriates me that she goes and talks with Bibi Netanyahu, saying she’s pro-this and pro-that,” Barr said of Palin’s stance on Israel. “But it’s like, ‘Do you hear anything this woman is saying – that her messiah will return to a Jew-free world? Does that bother you, Bibi? Because it bothers me.”

Roseanne said that in 2012, she will “run for president of the United States and also prime minster of Israel – it’s a two-fer.”

She views herself as wise enough for the jobs. “My book is kind of me rewriting Torah, because they say, after you study Kabbalah for 50 years and are bearded, you are qualified to write commentary,” she said. “And I fit the description.”