The beef is produced according to ancient Jewish law: A trained rabbi makes a swift cut across each animal's neck with a long, sharp knife. The blood drains quickly from the meat. Orthodox rabbis supervise the process and certify the beef as kosher.
But when an animal rights activist went undercover at one of the nation's top kosher slaughterhouses, he found practices that had raised deep concerns among some observant Jews.
The activist, from the group People for the Ethical Treatment of Animals, was assigned to the sausage line at Agriprocessors Inc. in Postville, Iowa. Whenever he could, however, he slipped over to the kill floor with a hidden camera. There, he filmed cattle struggling to stand minutes after they should have been dead. Some even staggered about after their throats had been slit and their windpipes ripped out.
The Orthodox Union, the largest kosher certification authority in the world, has declared that the procedures at Agriprocessors "meet all [our] standards to the highest degree." Meat from the plant -- sold under the brand names Aaron's Best and Rubashkin -- is certified not only as kosher, but as glatt kosher, which means it's deemed of the highest quality.
But kosher law is more than a procedural checklist. It's based on the ancient Jewish principle of tza'ar ba'alei hayyim -- the need to minimize pain to all living beings. And that's where the video has caused unease.
The Torah lists specific rules for treating animals humanely. For instance, oxen must not be muzzled on the threshing floor because it would torment them to see grain they could not eat. Rabbinical scholars nearly 2,000 years ago introduced the general principle that Jews must make sure the animals they use for work and food do not suffer.
That principle is integral to kosher slaughter, which, experts say, can be virtually painless if done correctly.
After watching the video, which PETA posted online, some rabbis have concluded that the animals at Agriprocessors suffer unnecessarily -- and have declared the meat unfit.
"The animals appear to be in agony," Rabbi Joel Rembaum recently wrote his congregation at Temple Beth Am in Los Angeles. "The meat that comes from there is not kosher."
He was shocked, he wrote, by the sight of animals with gashed necks thrashing on a bloody floor for a minute or longer. He also rejected as unacceptably cruel the equipment the plant uses: a revolving metal drum that turns the cattle upside down, baring their necks for the cut, and then dumps them out seconds later on the concrete.
Rabbinical scholars within the Conservative movement declared the inverted pen unacceptable for kosher slaughter in a legal opinion issued in 2000. The Iowa plant is one of the few in the nation that still use it.
"Does the meat technically fulfill the requirements of kosher slaughter? Yes," said Rabbi Elliot Dorff, a leading philosopher in the Conservative Jewish movement. "But if by calling it 'not kosher' [you] mean that the meat should not be eaten, I agree with that. The way it's produced violates Jewish law."
Many Orthodox rabbis dispute that conclusion.
They point out that the inverted pen was designed to speed the draining of blood -- an imperative in kosher slaughter. It's the method preferred by the chief rabbinate of Israel. And it is an ancient Jewish custom.
"This is the way we did it in the Holy Temple all those years. This is basically the exact way that God asked us to do it," said Rabbi Sholem Fishbane, who supervises kosher slaughterhouses for the Chicago Rabbinical Council.
"The PETA video wasn't pretty, that's for sure," Fishbane said. "But the meat was definitely kosher."
The debate comes against a backdrop of concern among some Jews about PETA's motives.
The group in the past has compared chickens to Holocaust victims, juxtaposing scenes of Nazi death camps with photos from factory farms. Jewish leaders also were appalled when PETA wrote the late Palestinian leader Yasser Arafat to complain that a donkey had been injured in a bombing attack in Jerusalem.
PETA coordinator Bruce Friedrich has made a point of praising kosher law for its emphasis on animal welfare. Nonetheless, some in the Jewish community view the undercover video as an anti-Semitic attack.
Nathan Lewin, an attorney for Agriprocessors, noted in a column in the Jewish Press that the Nazis launched their attacks on Jews in the 1930s with a campaign to discredit kosher slaughter as barbaric.
And Agriprocessors executive Heshy Rubashkin recently wrote customers urging them to join "with us in defending our religious practices against these extreme political attacks."
Customers like Leah Hoffmitz have followed the back-and-forth with some unease.
Hoffmitz, a graphic design professor from Los Angeles, said she always assumed that kosher slaughter meant humane slaughter. Hearing PETA's allegations "disturbed me," she said. But not enough to stop her from grilling Rubashkin steaks for dinner.