When I ask my teen-ager to do something he always seems to ask, “Why?” While it is often infuriating, I realized he is a lot like me. When I am asked to do something, I want to know why. When a recipe directs me to do something a certain way, I want to know why should I do it that way…maybe I was a bit infuriating to my parents?!?
Anyway, I was starting to write some blogs about the basics of cake making and felt more information was necessary. I can give you some great tried and true cake recipes and for some you will be happy to make the cake by following the recipe to the letter. If you are in this group, you can skip this blog and wait for the next one! But for some of you, understanding why we do the things we do and use the ingredients we do will make you a better baker! So if this is you, read on!
The most common ingredient in baking is wheat flour and from it we get gluten which is one of the three main things that give structure to our baked goods. The other two are egg proteins and starch. Let’s go into a little of the science on gluten so we can understand a little bit better some of our baking techniques.
This may surprise some, but flour does not contain gluten. Flour contains two proteins, glutenin and gliadin, that when mixed together with water create gluten. Glutenin provides strength and elasticity to gluten while gliadin provided its stretchiness. This gives gluten a unique nature that scientists call viscoelasticity. It means that gluten can stretch and change shape without breaking and can also partially come back to its original shape. This viscoelasticity allows the gluten to trap air in our baked goods so that our bread, cakes and cookies rise instead of becoming hard and puck-like. The unique nature of gluten is why it is difficult to recreate baked goods without it. Gluten-free products require mixtures of starches and gums to mimic the function of gluten. I promise a future blog on this very subject!
When we bake, we want different levels of gluten in our products. Generally speaking, for yeast raised breads we require more structure to maintain the rise of the heavy dough. Cakes and cookies are made from lighter doughs and batters and therefore require less gluten. In either case, if too much gluten is developed your baking goods will be tough, dense and chewy (not in a good way)!
The main way to control gluten in our baked goods is by the type of flour we use. For the home cook, there are three types of flours commonly available. Each of them contains different amounts of protein and therefore can create different amounts of gluten. Here is a table with some of the properties of each of them. They are arranged from most to least protein.
Note: Whole wheat flours usually have the highest level of proteins, but do not form as much gluten as white flours with the same protein content because shards of the germ included in the flour break some of the gluten strands as they are formed. Also, proteins from the bran and germ do not form gluten and components of the bran and germ actually inhibit gluten formation.
Gluten does not develop until the glutenin and gliadin are mixed with water. In bread making, the flour and water are usually in contact right from the beginning of the process giving us the best chance of creating strong gluten strands. When making cakes and cookies, the flour is usually not put in contact with the liquid ingredients until the end of the process. When we make pie crusts, we control the gluten formation by limiting the amount of water used. We do not add enough water to fully hydrate the glutenin and gliadin and therefore reducing the amount of gluten made. Too much water in a pie crust will make it dense and not flakey.
Gluten development also requires the mixing of the proteins with the water. Bread requires a lot of gluten so we work the dough thoroughly by kneading to create as much gluten as possible and to strength those strands. If bread is under-kneaded, not enough, or weak gluten is formed and the result is a loaf that is flat and dense (again, not in a good way). Conversely, we want to limit gluten in a cake, so the flour is usually not added until the end of the cake making process. This is also why flour is usually mixed at low speed or by hand and just until it is incorporated. Overmixing a cake batter will create a tough cake because too much gluten is formed.
Those are the basics of gluten and how it works in our baking. There are other things that affect the development of gluten. Ingredients such as fats and sugars interfere with gluten development. Salt, on the other hand helps to strength gluten strands. Hopefully this was not too nerdy and gave you a little knowledge to better your baking! Stay tuned for my next blog about the creaming method of cake making. In the meantime, if you have any questions about gluten and how it behaves in the baking process leave a message in the comments and I will get back to you!
Taking Control of Gluten by Kimberly Masibay, Fine Cooking, Issue 92
How Baking Works, 3rd Edition by Paula Figoni
Professional Baking, 5th Edition by Wayne Gisslen