My SWMBO makes incredible Irish Soda bread as well. I asked for the recipe awhile back and this is what she sent me. I STRONGLY recommend sticking your spent grains in the blender and really mushing them up.
Irish soda bread with spent grains.
(note: It is of note, that these recipes come from a time when yeast was not freely commercially available. The action of the soda served as a more readily available leavening agent. Although many recipes exist with additional ingredients added in, the simpler recipes such as this one are more authentic to the time period as many ordinary Celts would not have had access to such rich ingredients regularly. Irish soda bread is a daily item, not one reserved for special gatherings.
Soda bread nowadays often has a lot of additions such as sweeteners, fruits, etc that simply would not have been available at the time and place of its origination. It is dense and heavy and filling and quite good without the additions that have happened over time.)
This is just a base recipe...It does not matter what sort of flour you use, unlike yeasted bread the amount of glutenization is unimportant so this is a great bread to make with all whole wheat flour. The amount of spent grain that is added can be manipulated up and down as long as the dough holds together well enough.
This recipe makes two loaves. If you want to just make one, reduce the flour/grain/buttermilk but leave the soda and salt at the current proportions.
2 1/2-3 cups of flour
1-2 cups spent grain
1 Teaspoon baking soda
1 Teaspoon salt
14 oz of buttermilk
Preheat the oven to 425 F. degrees. Lightly grease and flour a cake pan or alternately this bread is fantastic when cooked in a cast iron dutch oven but i would lower the temp to about 400 for that.
In a large bowl combine all the dry ingredients.
Add the buttermilk to form a sticky dough. Place on floured surface and lightly knead (too much allows the gas to escape) (i just get my hands in there and mix it together until it is a nice dough, adding a little flour or buttermilk as needed....it should be slightly sticky.
Shape into a round flat shape in a round cake pan and cut a cross in the top of the dough. (the cross in the top allows the steam to escape...just cut down a quarter inch or so. I sometimes brush it with a little buttermilk and sprinkle it with some steel cut oats...makes it pretty
Cover the pan with another pan and bake for 30 minutes (this simulates the bastible pot). Remove cover and bake for an additional 15 minutes reducing the temperature to about 350 at this time.
The bottom of the bread will have a hollow sound when tapped to show it is done.
Cover the bread in a tea towel and lightly sprinkle water on the cloth to keep the bread moist.