There's no water in sight
"No matter how good the beer is, logistical snafus can ruin the day," notes Ruschmann. "The better festivals look after the little things, which actually aren't so little, such as plenty of opportunities to stay hydrated." If a festival is drier than Los Angeles in August or only stocks bottled water for purchase, it's likely it's just trying to get you in, get you tanked, and get you out without much concern for your overall experience. Also keep your eye out for waterless brewery booths, since any brewer worth their salt prefers a rinsed glass.
Bloggers aren't repping it
Next time you spot a questionable fest, first search the local beer blogs to see if they've posted anything about the festival to their sites or social media. If prominent members of the craft beer community have publicly endorsed an upcoming festival, it's most likely worth your time and money. And if they don't know about it, you probably shouldn't either.