When preparing to evaluate a beer you should just belly up to the bar and chug right? No, not at all. In order to properly prepare to judge beer you first need to clean you palate. The generally begins with brushing your teeth, flossing, and then brushing again. Special attention should be given to the tongue and roof of the mouth. Brush the roof gently and the tongue with vigor. I have found wiping the tongue with a paper towel is quite effective, but it tastes horrible. After you have finished all the brushing and flossing you should rinse until the flavor of the toothpaste is no longer present. Now you are finally ready to judge beer.
I’m sure I’ll hit this again, but while evaluating you should drink water to cleanse the palate and non-salted white crackers should be placed on the tongue, saturated with water and move the tongue against the roof of the mouth to cleanse the tongue. Do not chew the cracker, if you do you will end up with cracker in your teeth which will affect the taste of the beer you are evaluating. Remember between beers to drink plenty of water to keep the palate cleansed.
So in a nutshell before you judge at competition, brush your teeth, tongue and roof of the mouth and rinse until no more toothpaste flavor remains. Between beers drink plenty of water and dissolve unsalted crackers on the tongue when you need to fully cleanse your palate.