Expert witnesses are testifying Tuesday in the case of two prominent hot dog manufacturers suing each other for false advertising.

During Monday’s opening statements, federal Judge Morton Denlow had some fun with the attorneys about the topic at hand, calling the trial ‘wiener wars.’ But Tuesday, things took a more serious tone as testimony began. Kraft and Sara Lee, the owners of Oscar Mayer and Ball Park respectively, are suing each other for claims made in ads.

The first witness, Gerald Ford - not that Gerald Ford - testified for Sara Lee. Ford had surveyed a few hundred people, showing them an Oscar Mayer ad claiming it makes the best-tasting beef hot dogs.

Sara Lee says Kraft ran a faulty taste test and lied in those ads. Kraft has filed a similar lawsuit about Sara Lee’s ads. An attorney for Sara Lee says he also plans to call taste test experts to the stand.

The trial will also address the age old question of just what’s in a hot dog, anyway.

Monday, federal Judge Morton Denlow joked during opening arguments Monday, saying his favorite hot dog brand wasn’t represented in this case. But if there’s any indication how seriously Kraft and Sara Lee are taking the issues, look no further than the thousands of pages of documents they’ve filed over the last two years leading up to the trial. Judge Denlow joked Monday he had to stop reading the novel ‘Anna Karenina’ because the court filings in this case were longer than that book.

The trial is expected to last about two weeks.