Good tips from Boofer.
This is an odd one. What temperature are you aging this in? Are you using salt? Reduce temp and moisture, rub coarse salt as you wash. The color of this cheese is strong enough to stop washing now. Let the white stuff grow. It's natural geotrichum candidum (often referred to on this forum simply as "geo"). As it grows, it out-competes other rind flora so it will slow down the growth of the intruder. I wouldn't worry about infection. Probably something funky from your beer wash. Beer has very rich and diverse microflora.