The high-protein flour has 11.5% protein — the 00 flour has unknown protein content. I understand that "00" is a statement of the flour's grain size and not its protein level, but I assume that there's a normal range or expectation for the protein content of 00 flour.
So, would it be suitable to blend the two in some proportion to obtain something substitutable for AP flour?
Best Answer
First, in both the US and Australia, 00 flour has about the same protein content as AP flour, so you can use it instead, keeping in mind that it's more finely milled. To answer your broader question, yes, you can definitely combine flours together to approximate AP flour (keeping in mind that protein content in AP flour will range from brand to brand). In the US:
In Australia and other countries the flour percentages may differ from my chart above. I believe Australia has lower protein content in the US in general for AP flour, and 00 flour is also lower, but within the same range as AP flour there.