Federal food regulators -- not a court of law -- are best positioned to decide whether Yoplait Greek is indeed yogurt, a federal judge in St. Paul ruled Monday.

General Mills, Yoplait's maker, was accused in a lawsuit earlier this year of producing Greek yogurt that didn't comport with yogurt standards set by the Food and Drug Administration. Yogurt, like other foods from cheese to chocolate, has a federally defined identity.

U.S. District Judge Susan Richard Nelson partly dismissed the suit against General Mills, writing that "the FDA is in the best position to resolve any ambiguity about the standard of identity for yogurt -- a matter requiring scientific and nutritional expertise."

Yoplait is one the nation's top two yogurt brands. But Golden Valley-based General Mills was late getting into the booming market for Greek yogurt, a thicker, richer style with at least twice as much protein as conventional yogurt.

Most Greek yogurt makers have attained those attributes by straining the watery portion of milk, liquid whey. General Mills instead adds a thickener called "milk protein concentrate," which comes from filtered skim milk.

But milk protein concentrate is not included in the federal standard of identity for yogurt, the Minneapolis law firm Zimmerman Reed has argued on behalf of plaintiff Martin Taradejna of Chicago. Zimmerman Reed has been seeking class action status for the Taradejna suit.

General Mills has argued the opposite: Milk protein concentrates are covered by the FDA's yogurt standard. General Mills' "primary arguments in support of dismissal are generally persuasive," Nelson wrote.

However, she also noted that the FDA's most recent proposed standard for yogurt, made in 2009, "does not constitute a model of clarity."

The FDA's 2009 standard is still only "proposed" because -- as the agency explained in 2009 -- no public hearing had been held "due to competing priorities and limited resources," court records show.

Those conditions haven't greatly changed at the FDA. Still, Brian Gudmundson, an attorney with Zimmerman Reed, said, "We do think the issue is out in front [of the FDA] at the moment."

The Greek yogurt market has exploded since 2009. And issues raised in the Yoplait suit and others like it have recently gotten public attention, Gudmundson said.

Nelson dismissed the case "without prejudice," meaning a suit can be reinstituted depending on future events.

"We are pleased with the judge's decision and we stand behind the accuracy of our product label," General Mills said in a statement.

Mike Hughlett • 612-673-7003