NEW YORK - Religious Jews in the New York region may have to look elsewhere for a Shavuot delicacy, after learning that their favorite cheesecake lost its Kosher trademark this week. Junior's, a longtime Brooklyn establishment known for having the best cheesecake in New York, appears on a list of "Kosher Alerts" newly posted on the Orthodox Union's website. With immediate effect, its products are "no longer certified by the Orthodox Union and will no longer bear the OU symbol." The restaurant, which opened in 1950, is not kosher, but its mail-order cheesecakes had until now been approved by the OU, one of the largest kosher trademarks. Customers can order a range of flavors including Brownie Marble Swirl, Cherry Crumb and Sugar Free Low Carb Plain. But over Passover, when a non-Jewish foreman baked a batch of cheesecake for a long-time customer, the OU pulled the plug. According to third generation owner Alan Rosen, "it was basically a mistake." The foreman "did what he thought was best for the company and OU found out about it," said Rosen. "I honestly don't know why they came down so hard on us." Rosen may find out Friday morning, when he is scheduled to meet with the OU to discuss the decision. The OU would not specify why it has revoked its certification. "We anticipate the matter will be taken care of before Shavuot," said Bruce Bobbins, a spokesman for the restaurant. (The festival begins on the night of May 22.) "I'm confident it will be resolved." The current recipe for cheesecake was passed down from Rosen's grandfather who opened the restaurant in 1950. Harry Rosen, together with his baker, experimented with different crusts and textures until they arrived at the perfect combination. Whether a product is kosher or not is "more or less objective," said Rabbi Joel Roth, professor of Talmud and Jewish Law at the Jewish Theological Seminary, but the ways and means of kosher certification are not always a simple matter. "The purpose of kashrut supervision is to certify that everything is in order," said Roth. "If I were a supervising rabbi that gave kashrut, and I knew cheesecake is legally kosher but no longer considered people who manufacture the cheesecake trustworthy, I might withdraw my name from the hekhsher [certification]," said Roth hypothetically. But when a certification is removed, it is rarely an objective claim that an item is not kosher, Roth added. And just because one certifying agency revokes its certification, that does not mean that another won't certify it. "Sometimes kashrut certifying agencies compete," said Roth. "It's a business. It's also a service to the kosher keeping community, but ultimately it's a bit of a business." Though unfamiliar with the particulars of this case, Roth said he trusts what he knows of the OU. Reports of the OU's withdrawal of approval, first carried in a local Brooklyn newspaper, are now slowly making the rounds. One synagogue in Bay Ridge, Brooklyn, which had been gearing up for a special Shavuot order of Junior's cheesecake, is keeping congregants updated on its blog as the story pans out. It has become custom that, while studying Torah the night before Shavuot, religious Jews eat dairy products. "Any Jew who at the same time wants to appreciate the splendor of God's world would surely gravitate towards cheesecakeâ€¦and good cheesecake, if one canâ€¦p'shita," the Bay Ridge Jewish Center blog says with humor. The BRJC is eagerly waiting to see how the issue is resolved. Next week a ritual committee at the synagogue will discuss how to proceed if the matter isn't resolved in time for the holiday. Rosen said he is taking a "wait and see" attitude. "It was nice to offer OU product for Shavuos customers, but it's not the biggest part of our business," he said. "Do some people like it? Yeah. But I can't fight City Hall."