If you don't use an excluder, the queen will likely move up into the super and lay. She'll likely eventually go down.

For extracted honey, harvested late in the year, this is not a problem.

For cut comb honey, the combs are stained and not desirable at all.

so... if you extract, leave off the excluder.

If you cut comb, put it on.

Barnabas,

I agree totally with ccrb. I know I told you earlier in your other post to put the super on over an excluder for your honey bound brood box problem, but that was simply to keep the new queen from starting out up there.

I personally use an excluder between the brood box and the super very early in the spring until the bees build up and get the super half full of honey so that I know the queen will not likely go up there. By mid-April, I remove the excluder and pile on the empty supers over the half full one, prior to the main tulip poplar honey flow. This honey barrier will dissuade the queen from going up into the supers. Bees like their nest to have brood, with a layer of pollen over the brood, followed by honey.

Keith

Without an excluder, it's fascinating the shape of the brood chamber as the season goes on, it expands in a sort of bullet shape (it reminds me of an inverted rocket thrust pattern)and then the brood chamber contracts toward the end of the season, filled in with honey.

Of course when I do comb honey I do use an excluder, but although I love doing Killian boxes, haven't had time to do that lately.