Recipe from America’s Test Kitchen:
2 cups (8 oz) whole wheat flour
1 cup (4.25 oz.) unbleached all purpose flour
1 cup of wheat bran
1/4 cup wheat germ
2 teaspoons of sugar
1 1/2 teaspoons baking soda
1 1/2 teaspoons baking powder
1 teaspoon table salt
2 cups of buttermilk
375° middle rack, 40-45 minutes, rotate 1/2 way through. 185° internal temp. Cool for 1 hr.
I found, on initial mix, the dough was far, far, too dry. It kept crumbling apart and WOULD NOT hold together.
I kept adding splashes of buttermilk until I could get a loaf that would hang together.
Baking time had to go a little longer too, after 45 minutes it was only 145°. Maybe because of the added buttermilk. Running another 15 minutes brought it up to temp.
Regarding added liquid: one of the reasons it can vary so much is storage method and local humidity. We store our flour in plastic bins and in a very dry part of the house so I always need to add more liquid to recipes. Another reason is measuring by volume - flour can be compressed pretty easily (by the weight of other flour or tapping flour into a measuring cup) so volume measuring can be pretty shifty - a kitchen scale can really help in that regard.
Humidity is probably it, I did weigh out all the flour.
Was it 2 cups buttermilk or 2 pints? It seems very dry.
2 cups, but like I say, did not seem like enough. I kept adding until I got a dough that felt right.