So this is the part of my blog where I pretend to know what I'm talking about. Like, science and ingredients and stuff. But I really don't know what I'm talking about so we'll learn together! Let's start with basics. "We'll begin at the beginning and go on until we come to the end: then stop." Name that movie (hint: rhymes with Shmalice in Shwonderland).
But anyway, back to learning. Flour: let's talk about it! If you never baked in your life I would tell you that flour is a powder that is made from ground grains and seeds, and in some form or another, flour has been around sorta forever. The creation of flour made otherwise indigestible seeds digestible. It's nourished the masses, people!! But we've made many advancements in the flour department in recent years. What a world we live in now.
When it comes to baking, knowing the protein content of your flour is key. The more protein flour has, the more gluten it will produce. Ergo (I use sophisticated words), flour with high protein content can be used to make hearty crusty breads and on the other end of the spectrum, flour with a low protein content can be used to make light cakes with a delicate crumb. Here's the gist:
All Purpose Flour: 10-11.7% protein and generally true to it's name. It's great for most home baked good with the exception of a few rustic breads or super tender cakes
Whole Wheat Flour: 11-14% protein and uses all three parts of the wheat kernel (as opposed to one part of the kernel in AP Flour). It generally creates a heavier, heartier texture. While I've seen plenty of recipes that use 100% whole wheat flour, it's best to use a combination of both AP and whole wheat flours in a recipe to avoid overly dense and heavy baked goods
Cake Flour: 6-8% protein content and makes for a very light and delicate cake. The lower protein leads to less gluten development. And less gluten means a finer crumb.
Bread Flour: 12-14% protein. The high protein (along with kneading) means a lot of gluten development and results in a chewy, hearty bread.
Of course there are other flours (like pastry flour or self rising flour) but for a home cook, I think these flours do the trick.
So are you still with me? Or have I managed to bore you beyond imagination talking about gluten and flour? Well this is important stuff guys, ok? One day, knowing the protein content of cake flour just may save your life (it won't). So you're welcome. You owe me.
Information gathered from the one and only America's Test Kitchen and the other Interwebs sources.