The long-running U.S. soap opera All My Children is looking for a real Iraq-war veteran to play one on the show. The applicable plot line isn’t important here; listen to this short NPR item that tells about it, if you’re interested.
Many veterans have applied for the role, and the NPR announcer, Michele Norris, reports it this way:
Wilson [the casting director] says the next step is to winnow down the scores of applicants; a chosen few will be invited to New York for auditions.
I don’t know whether “winnow” was Ms Norris’s word or Ms Wilson’s, but it strikes me as the wrong one. Winnowing is the process of separating the heavy kernels of grain, which we want to save and eat, from the husks and other debris... usually by tossing the grain into the air and letting the wind blow away the lighter bits that we don’t want while the kernels fall back down.
Metaphorically, it means, in general, to separate things we don’t want from things we do. We can use the metaphoric sense in talking about spam filtering, where we winnow the mail stream, separating the wheat, the good mail, from the chaff, which we blow off into a spam pile somewhere.
But we don’t “winnow [something] down,” we just “winnow [something].” And, while we certainly can talk about winnowing a set of applicants, it does mean that we’re declaring those not making the cut to be “chaff”, undesirables, a nuance we’d usually prefer to avoid.
Maybe the word they’re looking for is “whittle”; we do “whittle [something] down” to make it smaller, and even though there, too, the bits that are whittled away are unwanted, the connotation isn’t as strong. It also has the sense that the reduction is done a bit at a time, not all at once, and that seems to make sense here too: they’ll likely be making a few passes through the list, reducing it with each pass.