I wanted to substitute Quinoa Flour for bleached in an apple nut-bread recipe - will it work, any adjustments for similar substitutions in general?
According to Bob's Red Mill, which makes the quinoa flour that I use:
You can do whatever you want :)
The flavor of quinoa is significantly different than that of white flour, and the consistency tends to be a bit grittier (although this is probably a function of the milling process). The other thing that quinoa lacks is gluten--the protein that makes bread doughs rubbery and stretchy.
Gluten is necessary when making yeast breads to capture the CO2 released by yeast to make nice bubbles in the bread, although there are workarounds to try and mimic the consistency that have been developed by people with gluten allergies. For some ideas, see http://cooking.stackexchange.com/questions/1661/what-are-good-techniques-for-getting-gluten-free-bread-to-rise for some ideas. If you aren't opposed to gluten, you can buy gluten, usually at health food stores. It is usually labeled as "vital wheat gluten". Add about 1/6th as much as the flour the recipe calls for.
If the bread is a quick bread (using a something like baking powder as the leavening agent), you should be able to sub without changing the recipe. You'll need to keep an eye on the consistency since the quinoa will probably absorb a bit more or a bit less water depending on how finely it was milled.