Does a server's beer knowledge affect the way you tip?

I've been going out to eat a lot over the past couple of weeks because I've been in the process of moving. Since we didn't have appliances in our kitchen until just this week, I had to leave the house in order to get a decent beer. With Barley's literally just around the corner from me now, it's the obvious first choice for me to stop in an grab a quick pint. After the past couple of visits I realized that I've had pretty good luck with servers at Barley's in Overland Park. Most of the servers there seem to be reasonably knowledgeable about what is new on tap, not just the name of the beer but the style as well. At a place like Barley's or the Flying Saucer I expect that from the wait staff though, and I'm sure they get training or cheat sheets for what's new on the tap (the girls at the Saucer have it easy with the big chalkboard above the bar).

Even when I go to a less beer-centric restaurant I still expect the server to be able to tell me what is on tap. I'm not looking for the waitress to be able to tell me original gravity or IBUs... I just want you to get the name of the beer right... I can Google the rest on my phone if I have to. Not everyone is a craft beer aficionado though, but what can you do? Well, there's always the tip... which brings me to my question:

Is it alright to tip your server less, or not at all, if they don't know what beers are on tap?

It may sound like a small thing at first but consider this... Wouldn't you expect a car sales man to know what new models were available on the car lot? What about a going to a book store, you'd expect the staff to know what new releases were on the shelves, right? Even if you keep the analogy within the food industry, would you tip a waiter the full amount if he didn't know what the daily specials were?

I'm a chronically bad tipper and I've never had to wait tables so my opinion may be a bit... biased, but if you've got beers on tap I expect you to be able to tell me what they are. Does that sound unreasonable?

Does the server's beer knowledge weigh in to your tip calculation at all? There have been times when I've had great beer conversations with the wait staff and I would have left a big tip... but like I said, I'm a horrible tipper anyways... It's a burden I have to try and live with.