How much of an affect does flour aging have on bread rise?

I've been wondering about this since the bread I make from flour I
mill myself consistently does not rise quite as nicely as the bread I
make from King Arthur whole-wheat-flour.

I use a Grainmaster Whispermill so the flour texture itself seems to
be as fine as the commercial flour and I use hard red wheat so the
protein ought to be pretty close, I think. The flour is fairly cool
when it comes out of the mill (I chill the berries first to avoid
heating). King Arthur claims "Includes 100% of the bran and germ of
the wheat berry" in their flour.

Other than the whole-wheat flour every other ingredient is identical,
same cycle in the machine, room temperature doesn't much vary, nor
does air humidity.

Could it be because my flour is generally a day or less old when I
make bread with it?

Should I let it age for a time before using it?

If so, how long and where? Room temperature or refrigerated?

Could just be the difference between their wheat and what I've got,
but I'm wondering if flour aging might explain at least part of it.

......Alan.

--
Curiosity killed the cat -
lack of it is killing mankind.