So let's talk about substituting whole wheat or whole grain flours for white and all-purpose and white bread flours. I like to substitute whole grain flours for both flavor and for health, but primarily for me, it's flavor because I think that the whole grains contribute more flavor to the loaf than white flours. When you substitute whole grains they also add that health component that's really important as well.
The question that I'm asked most frequently is what percentage of whole wheat flour can you substitute for white flour and how do those substitutions work? And my answer is, you can basically substitute whole wheat flour for all of the white flour. You just have to be aware that that will change the bread composition a little bit and it will make it a little drier and a little coarser. If you want to try to make a dough that's very similar to your white bread dough with just some of the whole wheat, my favorite composition is 70% whole wheat and 30% white flour.
Where that 70% of the whole wheat flour is replacing the white flour. By leaving in that little bit of white flour you still have that gluten from the white flour and you still have a similar consistency. You can also do that with rye flour. You can substitute up to I would say, 70% of the white flour with the rye flour. If you do substitute 100% rye, you have to be aware that rye does not contain much gluten, and so you would have to change your recipe, and basically bake your bread in a pan.
Any other types of grains I think my favorite substitution is 50/50, and you try 50/50 out and if the dough feels drier, add a little bit more water and use your hands to touch and to guide you. If you want to substitute more grains after that just keep upping the percentage of whole grains, until you've reached a percentage that you're happy with and gives you the bread that you're desiring to make.
Just keep in mind that when you add more grains or you add whole wheat flour for white flour, the whole wheat will absorb the water so you actually need to add more water to your dough, and so what you want to do is substitute the flour and then touch your dough and if it feels dry, just knead in more water. That's a very quick explanation on how to substitute whole grain flours for white flours.