[potench]

Perhaps calling it "culture fit" is the problem - it's not specific enough. Define more clearly the characteristics and signals you're looking for. Evaluate your team and culture to better identify the characteristics you're trying to match in a candidate. For instance, instead of "culture fit", say you are looking for signals that someone is "passionate about web development", then think about evidence that supports the characteristic: eagerly learning, involvement with development-community, excited about new technology, willing to experiment, etc. You can also provide evidence that shows a candidate isn't "passionate". Just a matter of semantics.