The Function of Flour in Baking

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The Function of Flour in Baking Lesson Overview:

In traditional baking there is no other more important ingredient than wheat flour. It builds the structure of our baked goods and understanding how it functions is essential for successful baking.

Walk down any baking aisle in a grocery store and you will likely see a wide range of varieties of wheat flours. So let’s review all of the different varieties of flour and their best uses.

Watch the Video Lesson

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Flour’s Function in Baking

The main function of flour in baking is to build structure. When the proteins found in wheat flour are hydrated, they interact with each other forming what is known as gluten. As dough or batter containing wheat flour is worked, an elastic network is developed. This gluten network stretches to contain the leavening gasses in the baked good. Wheat flour and the production of gluten are essential for the structure of traditional baked goods. (We will cover more in depth information about gluten production in lesson 8.) 

Categories of Wheat Flour

Wheat flour can be divided into 2 main categories: Whole wheat flour and white flour. White flour is then broken down into 2 more subcategories: bleached flour and unbleached flour. Additionally, these categories are divided even farther into many different varieties with varying uses.

Whole Wheat Flour vs White Flour

All wheat flour is made by grinding down wheat grain. Wheat grain contains three parts: the bran, the germ, and the endosperm. Whole wheat flour is exactly what it sounds like: the entire wheat grain, including all 3 parts, are ground into a fine flour. White flour is made from only the endosperm of wheat, which is paler in color and produces a softer texture flour.

Whole wheat flour is darker in color, more flavorful, and more nutritious than white flour. It does however have a more coarse texture and is more absorbent that white flour, requiring a higher liquid ratio.

Bleached vs Unbleached Flour

White flour is also divided into two main categories: bleached and unbleached. You might not realize, that technically, all flour is bleached. The difference is that flour that is marked as “bleached” has been treated with chemicals to get to that point, while flour that is marked “unbleached” has naturally reached the bleached state.

WHAT IS UNBLEACHED FLOUR?

As flour ages, it naturally becomes more white in color and softer. Naturally aged flour is labeled as “unbleached” and is ivory white in color. Unbleached flour takes much longer to produce than bleached flour and is therefore often more expensive.

WHAT IS BLEACHED FLOUR?

Bleached flour is treated with chemicals (typically chlorine gas or benzoyl peroxide) to speed up the aging process. This not only produces flour with a bright white color, but also creates a flour with a finer texture and slightly less protein content than unbleached flour.

WHEN TO USE BLEACHED VS UNBLEACHED FLOUR?

For most everyday baking scenarios, the difference in baked goods made with bleached flour vs unbleached flour is really negligible and just a matter of personal preference. Though some professional bakers believe that unbleached flour should be used for sturdy baked goods like yeast breads and bleached flours should be used for more tender baked goods such as muffins, cakes, and delicate pastries.

Varieties of Flour

Wheat flours also are made in a wide range of varieties depending on their intended use. All flours have varying levels of protein content, which is important to note because a stronger gluten structure will form in baked goods made with higher protein flours.

All-Purpose Flour

• What is All-Purpose Flour?: All-purpose flour is a white flour made from hard winter wheat and is a versatile wheat flour with a moderate protein content. This variety of flour is meant to function as its name suggests: all-purposes. All-purpose flour is the flour most commonly used by home baker’s and does come in both bleached and unbleached varieties.
• Protein Content in All-Purpose Flour: 9.5-11.7% (depending on the brand)
• Best Uses for All-Purpose Flour: Any everyday baking
• Weight per Cup of All-Purpose Flour: 4.25 oz, 120 gr

It is worth noting that the White Lily brand all-purpose flour is made from soft winter wheat. This produces an all-purpose flour that is much lower in protein content than other all-purpose flours, at around 7-8.5%. This brand of flour is highly regarded in the South as the best for making biscuits.

Bread Flour

• What is Bread Flour?: Bread flour is a white flour made from hard spring wheat which has a higher protein content than the wheat used to mill all-purpose flour. Therefore, bread flour produces a stronger gluten structure in baked goods. Bread flour is available bleached or unbleached.
• Protein Content in Bread Flour: 12-14.5% (depending on brand)
• Best Uses for Bread Flour: Yeast breads, any sturdy baked good where chew is desirable
• Weight per Cup of Bread Flour: 4.25 oz, 120 gr
• Substituting Bread Flour: While bread flour is best used for yeast breads and sturdy baked goods, it can be substituted for all-purpose flour if absolutely necessary. Take extra care not to over-mix your batter if you are using bread flour in place of all-purpose flour. Avoid using bread flour for any very delicate pastries. Alternatively, all purpose flour can be substituted in for bread flour if absolutely necessary, but your end results will vary. Breads may not rise quite as high and will likely have a more closed crumb.

Cake Flour

• What is Cake Flour?: Cake flour is a very finely milled white flour made from a soft winter wheat. Cake flour is also traditionally very heavily bleached. The bleaching process and the variety of wheat it is made from produces a flour that has a very low protein content. The flour is velvety in texture and produces beautifully delicate pastries. While unbleached cake flours do exist, they are reported to preform poorly compared to traditional bleached cake flour.
• Protein Content in Cake Flour: 6.5-8% (depending on brand)
• Best Uses for Cake Flour: Cakes, pie crusts, biscuits, delicate pastries
• Weight per Cup of Cake Flour: 4 oz, 112 gr
• Substituting Cake Flour: If needed, a cake flour substitute can be created by combining all-purpose flour and some cornstarch together and sifting it over and over again. You can read more about cake flour substitute here.

Self-Rising Flour

• What is Self-Rising Flour?: Self-rising flour (also known as self-raising flour) is a variety of white flour that has salt and baking powder already combined into it. This variety of flour can make quick work of simple recipes by combining three ingredients into one. The baking powder is also evenly distributed throughout the flour so it gives an even reliable rise to baked goods.
• Protein Content in Self-Rising Flour: 8.5-11% (depending on brand)
• Best Uses for Self-Rising Flour: Quick breads such as biscuits, muffins, pancakes, and scones.
• Weight per Cup of Self-Rising Flour: 4.25 oz, 120 gr
• Substituting Self-Rising Flour: You can make a self-rising flour substitute by combining all-purpose flour with baking soda and salt. Read more about making your own self-rising flour here.

Whole Wheat Flour

• What is Whole Wheat Flour: Whole wheat flour is a flour milled from the entire wheat grain including the bran, germ, and endosperm. Whole wheat flour is an unbleached flour and is noticeably darker in color than white flours. It also has a slightly coarser texture than all-purpose flour and has more flavor and nutrients. Even though whole wheat flours do tend to have a higher protein content, their gluten structures are weaker due to the bran present in the flour. For this reason, whole wheat flour is often used in combination with white flour.
• Protein Content in Whole Wheat Flour: 12-14% (depending on brand)
• Best Uses for Whole Wheat Flour: Whole grain breads, substituting a small portion of white flour in a recipe to add flavor and nutrition
• Weight per cup of Whole Wheat Flour: 4.25 oz, 120 gr
• Substituting Whole Wheat Flour: Whole wheat flour is more absorbent than white flours, therefore a higher liquid ratio is needed in a recipe if substituting wheat flour for white flour. I tend to subtract 2 TBSP of wheat flour for every 1 cup of white flour I am substituting. I also recommend starting by substituting only a small portion of the white flour for wheat flour in a recipe to start.

White Whole Wheat Flour

• What is White Whole Wheat Flour?: White whole wheat flour is still a 100% whole wheat flour, however it is milled from a variety of hard wheat that is white in color rather than the red wheat that traditional whole wheat flour is milled from. This variety of wheat is milder in flavor while still containing the same nutritional content as other whole wheat flours. White whole wheat flour should be thought of as identical to traditional whole wheat flour except for the milder flavor.
• Protein Content in White Whole Wheat Flour: 12-14% (depending on brand)
• Best Uses for White Whole Wheat Flour: Whole grain breads, substituting a small portion of white flour in a recipe to add some flavor and more nutrition
• Weight per Cup of White Whole Wheat Flour: 4.25 oz, 120 gr
• Substituting White Whole Wheat Flour: White whole wheat flour can be substituted 1 for 1 with regular whole wheat flour. You can also substitute it for white flour the way I suggest above with wheat flour: subtracting 2 TBSP white whole wheat flour for every 1 cup of white flour you substitute.

Whole Wheat Pastry Flour

• What is Whole Wheat Pastry Flour? While white whole wheat flour is milled from hard white wheat, whole wheat pastry flour is milled from soft white wheat. This produces a white whole wheat flour that has a lower protein content which makes it more suitable for delicate pastries than traditional whole wheat flour.
• Protein Content in Whole Wheat Pastry Flour: 9-10 % (depending on brand)
• Best Uses for Whole Wheat Pastry Flour: Cookies, pie crusts
• Weight per Cup of  Whole Wheat Pastry Flour: 3.4-4.25 oz, 96-120 gr (depending on the brand)
• Substituting Whole Wheat Pastry Flour: If you want to substitute whole wheat pastry flour with another flour, I suggest substituting 1/2 whole wheat flour and 1/2 all-purpose flour. You can also substitute whole wheat pastry flour in for all-purpose flour cup for cup.

Italian Style 00 Flour (Doppio Zero Flour)

• What is 00 Flour?: 00 flour (also known as doppio zero flour) is an Italian style of flour that is very finely ground and used commonly in pizza dough and pasta making. In Italy, they categorize flours by the coarseness of the grind- 2 being the most coarse and 00 being the most fine. It is a common misconception that this flour is low in protein content. However, because this style of flour is ground from durum wheat instead of red wheat, the gluten structure is not as elastic. This style of flour can be difficult to find in the US.
• Protein Content in 00 Flour: Varies widely from 8.5-12.5% (depending on brand), 12.5% is the most common
• Best Uses for 00 Flour: Pizzas and pastas
• Weight per Cup of 00 Flour: 3.8 oz, 106 gr

Flours to Keep on Hand

Now that you understand the difference between all of the varieties of flour you might be feeling overwhelmed with which ones you should keep stocked. While I think it is fun to test out different kinds of flour I have never tried before, there are really only 4 flours that I keep on hand regularly for my baking. If you are an avid baker there are 4 flours I recommend keeping on hand for the most versatility in your baking:

• All-Purpose Flour (bleached or unbleached- your preference)
• Bread Flour
• Cake Flour (I prefer bleached because it performs better, but your preference)
• Whole Wheat Flour (Regular or White Whole Wheat)

I also recommend storing your whole wheat flour in the freezer unless you go through it quickly. Because whole wheat flour does contain the entire wheat grain, it has a shorter shelf life and go rancid before it is used up. Freezing it will increase the shelf life.

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Homework for this Lesson

As always, the homework is optional but is a good way to practice.. For the homework assignment, I want you to pick up a flour you have never tried before and bake something with it! What do you notice about how the flour performs? You can bake anything you like, but I will leave some suggestions below for you!

• Bread Flour: Easiest Bread Recipe | Epi Bread | French Baguettes
• Cake Flour: Best Yellow Cake | Classic Pound Cake
• Whole Wheat or White Whole Wheat Flour: Honey Whole Wheat Bread | Whole Wheat Summer Squash Chocolate Chip Muffins
• Whole Wheat Pastry Flour: Whole Wheat Biscuits | Whole Wheat Rum Raisin Oatmeal Cookies

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Resources

• On Food and Cooking: The Science and Lore of the Kitchen
• The Professional Pastry Chef
• Professional Cooking

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