Although I have been brewing successfully for over 4 years I have only recently started kegging my beer. This is the second time that I carb at 30 psi then, after 2 or 3 days, I reduce the pressure to 10 - 12 psi to dispense but I still have a problem with too much head in the glass. With the glass full to the top with it's head, there is only about 2 inches of beer in the glass. The beer settles down nicely and retains a beautiful creamy head but it seems that it takes way too long to fill a glass. What should I do to properly pour a 3/4 full glass with a nice head the first time? I've tried lowering the psi to 8 lbs and increasing it to 20 psi with the same results. I must be doing something wrong....