Try their whole wheat recipe, too: http://www.kingarthurflour.com/recip...t-bread-recipe

Another thought too:
A lot of recipes do better if you do your measurements by dry weight rather than by the liquid measurement - i.e. 8oz vs a cup. Part of the reason for that is that a bagged flour tends to be clumped and compacted together and you'll tend to measure out way more flour than you would with fresh ground. Try it one day, if you can get freshly milled berries, sprinkle them from a scoop vs the same process from a bagged flour. I found that I was putting in almost 1/3 cup more flour with the bagged flour than the freshly ground based on the dry weight of them which also made for a heavier drier loaf.

When I bake my whole wheat bread I add 2 tbsps vinegar or lemon juice per 2 1/2 cups of the flour. I ususally use vinegar because the taste disappears and the lemon juice can still be tasted. Apparently the acid allows the gluten strands to develop. I hope I am not repeating what has already been posted. My time is limited so I don't have time to read every post.
Whole grain bread is a heavier loaf as you will notice when you buy whole grain at the store. But this method does make a lighter loaf.
Lynda

Lately, I've been making a lot of sourdough. Using all white flour though. Because sourdough is mostly only flour and water, I add my own "dough enhancers" which amounts to powdered lecithin and vital wheat gluten. This creates a soft bread with great rise. I've been thinking I need to give it a try with whole wheat one of these days.

I've been using this one lately:
http://allrecipes.com/Recipe/San-Fra...urdough-Bread/

The changes I've made:
Water instead of milk
butter instead of margarine
half fresh ground whole wheat, half white
I leave off the onion and the egg wash.

I have a pan of water under the rack the loaves are on to help the bake.