It really does depend on the acorn you get. Red oak acorns are really
time consuming to leach and eventhen they seem to retain some amount of
bitterness, which I toned down by mixing with other nuts and dried
fruits. But when you do white oak acorns, they hardly need leaching at
all...
My process ( which could have used a few more hours of leaching I think)
was to place chopped/broken acorns (not whole) in a mesh bag ( you cn
use cheese cloth tied shut with a rubber band or such things) and boil
for an hour, drain water, add fresh, boil again. I did this 5 or 6
times, for about2-3 cups of acorn pieces. ( and that maybe overstating
it)
I used red oak acorns this time, then I roasted them in the oven.  The
boiling water smells soemtihng a kin to maple or brown sugar...which is
strange since we're supposedly getting rid of bitter tannins, and I
wonder how much that boiling  changes the nutritional content of the
acorns....

 I know a lady who waits till early spring to collect hers, after they
have been sitting under the snow all winter, and she says they are near
edible then.

I think your best bet would be to try to get a less bitter species
White oak (quercus alba) or  bellota emory oak ( quercus emoryii) are
good ones to try.

Or mix the acorns with other things :D
Good luck!
darcey