Food Science: Flour

flour1Flour is an essential ingredient in lots of recipes, mostly for baked goods. But do we really know how flour works? Time after time we mindlessly add flour to our cookies and cakes, overlooking the true importance of it and just waiting for the moment when we get to lick the spoon clean. The truth is, knowing the science behind flour and how it interacts while baking can give us lots of insight about the foods we’re making, the type of flour we should choose for specific recipes, and helpful tips on how to improve these recipes to get the most delicious results.

The real reason flour is so vital in the baking world is because of the stringy protein that forms when wheat and water mix – otherwise known as gluten. I know nowadays saying the word gluten is almost as bad as shouting, “Fire!” in a movie theater, but gluten is actually your friend when it flour2comes to baking. Gluten plays such an important role in baking for many reasons. First of all, it acts as a binding agent for the dough and holds it together. Also, it traps the gases that are released by yeast during fermentation, which prevents bread from being too dense. Furthermore, gluten is ultimately responsible for the shape and texture of baked goods.

But how exactly does this miracle protein work? Gluten is made up of two proteins, glutenin and gliadin, and when mixed with water these two proteins combine to create strong, elastic gluten strands in the dough. These gluten strands become stronger and more developed the more you mix the dough, which ultimately affects the texture and type of dough that is formed.

Choosing flour with the appropriate amount of gluten content can actually make or break you in the kitchen. Different types of dough flour3require different levels of gluten content. For example, foods such as breads, pizza dough, pasta and other yeast-raised dough have higher gluten content; the higher amount of gluten makes the breads elastic and stretchy. Other baked goods, such as cakes, cookies and other pastries, require less gluten, which keeps them lighter and fluffy. Therefore, as expected, bread flour has a higher protein content than pastry or cake flour.

We asked a professional baker and food blogger, Amanda Light (from, her opinions on flour and she gave us some very helpful hints! “All purpose flour is just that, all purpose. You’ll get good results whether you’re baking a cake or whipping up some bread,” says Amanda. “If you are a more experienced baker you can use different types of flour, that generally vary on the amount of protein content they have. Bread flour has the most protein (making it dense and chewy) while pastry and cake flour have the least (making it light and fluffy). More experienced bakers can add protein to their flours with varying results but I use all purpose flour for almost everything in my kitchen and have almost always had delicious results!”

Thanks to Amanda’s tips and some additional research, we put together a list of different types of flours and their uses.

flour4Bread flours, durum semolina and whole-wheat flour have the most protein, about 12-15%. Bread flour is made from hard wheat and forms strong, durable gluten to make the elastic dough necessary for good bread. Whole-wheat flour will provide a more wheat flavor, and is slightly darker than white flour. It is made by milling the whole-wheat berry instead of just parts of it. These flours are therefore ideal for yeast-raised dough and pizzas.

All-purpose flour, as its name suggests, can be used for pretty much anything since it is a mix of hard and soft wheat. It falls in the middle in regards to protein content, 9-12%, and thus can be used for most home-baked goods. It also comes in bleached and unbleached versions. The difference between these two is that bleached flour has been treated with an agent to whiten it and has its nutrients restored, while unbleached flour remains untouched and keeps all its nutrients on its own. In regards to baking results, however, these two are equal and will both work the same.

Pastry flour is made from soft wheat and contains 8-9% proteins. This results in weaker gluten and a softer product and will result in a crumbly, fluffy texture. Thus, it is mainly used for different types of pastries. Cake flour is very similar to pastry flour; it is also made from soft wheat, but falls just below pastry flour with 7-8% protein content. The lower protein content ensures that cakes turn out fluffy and tender.

So next time you aimlessly throw a bag of flour into your shopping cart and bolt out of the baking aisle, take a minute to think about what kind of flour you’ll be needing. Your baked goods will thank you (and taste better!).