It’s that time of week when we answer the questions you’re too drunk or shy to ask … This one comes from Paul:The last few times I’ve had tap beer, I got sick. Someone told me it’s the keg lines, and some bars don’t change them.This is a tricky topic, in the same way that if someone gets sick after eating out they always blame the last thing they put in their mouth (or the mussels). I know many people that won’t drink tap beer because of the same wisdom, and unfortunately, there’s a tiny kernel of logic to it.Kegs are stored in a keg fridge, typically located under the back bar or in a walk-in cooler near the kitchen. Sometimes when the bartender pulls the tap, the beer can be coming from as far as 50 feet away. That’s 50 feet of tubing that needs changing on a regular basis, because tiny flotsam and jetsam can build up in the line. Yes, most beer is filtered, but any residue on the outside of the keg or the connector can lead to contamination. A few unspent yeast cells in the tubing can trap any number of things, and bacteria will grow.Different people have different tolerances for any number of bacteria and molds, be they the kind found in cheese, beer, or around the house. Just like the bacteria levels in mussels and oysters can fluctuate but still be in the safe zone for the majority of the population, some of the schmutz in an unclean line will cause a different reaction in people who are more sensitive than others.More than just making you sick, unclean lines affect the taste of a beer. That’s why many brewpubs in our city are maniacal about changing their tap lines; they want to show the product in the best light. Some restaurants, however, treat these conduits like plumbing, and only pay attention to the tap lines when they clog up.Problem is, the only way to know how often a bar changes their lines is to ask. So that tags you as a real winner right there, and the odds a bartender will tell you the truth are about the same as heads or tails. If you decline to ask, remember: You can’t ascertain the keg system’s cleanliness by the pedigree of the beers on tap, the prices on the menu, or the caliber of the bar. To wit, the filthiest place I’ve ever worked is a five-diamond hotel that shall remain nameless.My rule: When in doubt, I ask how often they rotate taps and kegs and who changes the lines, realizing this makes me out as a jerk. I am very wary if the bartender or manager can’t give me or find me an immediate answer.My wish: Beer distributors should care about their products enough to monitor bars that carry their kegs, and I think a log of how frequently tap lines are changed should be a part of any restaurant’s health inspection.