MILWAUKEE—Rhonda Dannenberg, a suburban mother of three, stuck her nose in six glasses of beer at the MillerCoors brewery here and swished a bit of each in her mouth. Then she delivered the kind of frank verdict that's shaking up the mens-club world of beer tasting.

"I got a strong bruised fruit," Ms. Dannenberg, 36 years old, said of one of the Miller Lite batches, drawing a few nods from the three other women and two men at the table. "Slight cardboard taste. Oxidized. Unacceptable."

At many companies, the assembled panelists would have been men, typically brew masters and other technical types. And it makes sense. To judge from TV commercials, men like beer better than women do and sometimes even seem to like beer more than they like women.

But the British company SABMiller PLC decided several years ago to reach deeper into its employee pool to find adept tasters, inviting marketers, secretaries and others to try their hand. The company concluded that women were drinking men under the table.

"We have found that females often are more sensitive about the levels of flavor in beer," says Barry Axcell, SABMiller's chief brewer. Women trained as tasters outshine their male counterparts, he says.