Shannon Hoffeditz's team just finished writing a $500 ticket for a little old bartender.

"That's one of the hardest parts of our job," says Hoffeditz, an inspector with the Oregon Liquor Control Commission (OLCC).

Eli, an 18-year-old minor decoy working for Hoffeditz, has just bought a beer in the Republic Café on NW 4th in Old Town, and as a consequence the server and licensee will each now face second violation fines of up to $500 for the server and $4,950 for the licensee. The server has worked in the Republic for more than 50 years, says Hoffeditz, and is due to be retiring soon. Unfortunately the OLCC caught her working without a valid service permit last quarter, so the second penalty is more severe.

"That's going to be really tough for her," Hoffeditz says. "But we have to be fair to everyone."

Meanwhile a second decoy, named Megan, who like Eli is 18 years old and a police cadet, has just bought a Coors Light in the Crown Room, across the street. The server and the licensee now face fines of up to $250 and $1,650.

"I just kept talking on my cell phone so I didn't look nervous," Megan says, as we stand on the corner of NW 4th and Davis, waiting for Eli's return. "And then dropped a five-dollar bill on the bar. I felt kind of bad about it when they served me, actually."

So far it's a bad night for Hoffeditz—or a good night, depending on how you look at things. Either way, bars in Old Town/Chinatown are getting caught serving plenty of minors tonight—Eli also bought a Bud Light in the House of Louie.

The OLCC picks its districts and bars on a random basis, Hoffeditz tells me, as we continue on the mission. Tonight, teams working alongside Hoffeditz will hit 71 premises in North and Northwest Portland, and 20 will serve to minors—a 28 percent minor sales rate, which is slightly higher than the statewide average of 22 percent in 2007.

We stop in at McFadden's on NW Couch, where the head of security hands Hoffeditz a stack of 50 fake IDs, confiscated over recent months. Among them is a doctored driver's license from Saudi Arabia.

Several locations later, a waitress in the Wong Kee BBQ Dim Sum Restaurant on NW 4th brought Eli a Budweiser. Police Officer Hank Hays, who has been accompanying Hoffeditz and the team on this mission, tells the waitress he's just watched her serve a minor, and reads her the Miranda rights. Along with paying the OLCC's fine, the waitress will also have to appear in court on a class A misdemeanor, furnishing alcohol to a minor—which itself carries a $350 fine for a first conviction, and she doesn't look happy about it.

Thanks to language barriers, we're in the Wong Kee for about 30 minutes while Hays writes the waitress a ticket to appear in court. During that time, nobody comes in to eat, and I think about the impact a $1,650 fine is going to have on this business.

Having purchased my first beer in a South London pub when I was 14—there, it's legal to drink when you're 18, and enforcement is a lot more relaxed—I've always been intrigued by this country's puritanical attitude to minor sales. After quitting drinking 13 years later, last July, I do wonder whether a stricter minor sales policy in my home country may have prevented some of my more regrettable excesses. Still, it's hard for me to watch the waitress being told she has the right to remain silent without feeling sympathy.

The last place to serve Eli is the Shanghai Steakery on Broadway. A George Michael dance mix plays as OLCC Inspector Paul Rosenow asks the bartender how old he thought Eli was—who, with his chubby cheeks and baggy T-shirt, looks underage to me.

"I'd say almost 30," the barman says.

Not quite.