Thanks! Yeah I have a bunch of recipe books and one that teaches theory/baking methods. I've never seen cake flour in grocery stores, whats the difference between cake flour and normal flour? Someday I want to make a triple layer alien cake, two of the cakes chocolate the other vanilla, covered with neon green frosting and put on sugar aliens to decorate and write "Happy Alien Party" on the top. But its way too advanced for now.
Lol, your alien cake idea reminds me of a cake a friend baked for Halloween . She shaped it like a dead rat; sliced it lengthwise and hollowed out the inside in the shape of the skeleton. She then made a rat shaped skeleton out of white chocolate and placed it inside the cake. She then sealed it up and iced. People at the party totally freaked out when they bit into the "bones". I thought that was the best Halloween cake ever!
Your question on the differences between flours is an excellent question. Using the appropriate flour for the application is critical to success.
The four most common flours in the grocery store are:
all purpose flour
bread flour
whole wheat flour
cake flour
The difference between them is the percentage of protein content and flour treatment.
all purpose flour will have a protein content of 10% - 11.7% depending on brand.
Gold Metal and Pillsbury brands have the lower 10% protein and are bleached. These flours are more suited for cake, pie and tart crusts, delicate cookies like shortbread, muffins, and quick breads like banana nut bread.
Gold Metal makes an all purpose unbleached flour with about 10% protein as well. It can also be used for the applications above. But because its unbleached, it will produce a coarser texture and heavy product.
King Arthur Flour all purpose has 11.7% protein and is unbleached. The higher protein content and the unbleached flour makes it more suitable for dinner rolls, pizza crust, some muffins like bran muffins, sturdy cookies like chocolate chip and oatmeal, breads baked in loaf pans. This flour is too high in protein to make a good cake. The texture is coarse; the weight very heavy; the rise very low. The higher protein content means it will absorb more liquid that the lower protein flours. As such, it will make a very tough pie crust.
Whole wheat flour is very high in protein and is always unbleached. Whole wheat flour is made by milling the entire wheat berry: bran, germ, and endosperm; hence the name "whole wheat." The all purpose flours are made with only the endosperm. Whole wheat flour will absorb an extraordinary amount of liquid. When baking with whole wheat you have to mix it with other flours as it will barely rise. You have to use 1:1 of water to flour as well because it absorbs so much liquid.
Cake flour is milled from a wheat species that is naturally lower in protein. It is made from the endosperm only. It is finely milled and bleached. As such, it will not produce a lot of gluten when mixed into a batter. It also absorbs less water. So the cake texture is very fine; the weight is very light, the color is also light; and it is very soft. We refer to it as having a "short bite" meaning it does not need to be chewed much to eat. By contrast, baked goods that do not have a short bit are "chewy." Bread is "chewy" Cookies are "chewy".
The type of flour you select for your baking projects depends on the characteristics of the baked good. Some times mixing flours is best. I routinely mix all purpose and bread flour for things like croissants and rolls.
A lot of bloggers claim you can "make" cake flour by removing a couple of tablespoons of the all purpose flour and replacing it with cornstarch. That is completely bogus, you cannot make cake flour. First the issue is overall natural protein content. Adding two tablespoons of cornstarch is not going to reduce/dilute the protein content of all purpose flour. It just simply as the properties of cornstarch to the batter. And the properties of cornstarch is not desirable in cake.
Cornstarch has extraordinary absorption capacity--far more than cake flour and all purpose flour. Cornstarch has incredible thickening properties when it absorbs moister and subjected to heat. The temperature in which cornstarch will thicken is 180°F - 210°F. The internal temperature of cake when it's done is between 205°F - 210°F depending on the type of cake. That is well within the thickening temperature of cornstarch. So adding cornstarch is going cause the cake to be thicker and heavier--the very opposite of what you want in a cake. If you cannot find cake flour, its better to use Gold Medal or Pillsbury all purpose flour than to add cornstarch.
Cake flour is sold in boxes
Because cake flour is finely milled and low in protein, if you squeeze it in the palm of your hand it will clump. Flour with higher protein will not clump like this. I transfer my flours to air tight containers after opening the packages. Some time the labels fall off the canisters. If I'm in doubt about the type of flour I will examine its color against other marked flours in my pantry and do the squeeze test to determine the type of flour.
