I Have been been wondering about the correlation between Protein content in flour and their useability for baking. Through some web search,I learned that Protein content of a flour gives nothing more than a hint as to the strength of the flour. I read that some amino acids (that make up protein) are usually soluble and contribute little to the strength of a flour.
OK so I've been having an AWFUL time trying to make my bread come out right and I finally found out what's wrong.
ConAgra Harvest All Purpose Flour is about the same protein content as biscuit mix. It's barely above a cake flour. At least what's available in MY area is.
I had to call ConAgra to get this information and if you are in some other part of the country it's going to be different. Unlike King Arthur, Con Agra does not mill their wheat to meet any particular definition of what we would typically think of as "bread flour" or "all purpose flour".