When I was younger, every Sunday night my mom and dad would make a fabulous dinner. My mom would make her famous Anadama bread, while my dad would whip up a batch of his delicious blueberry muffins. My dad would mix all of his ingredients into a batter in a large bowl while my mom would knead her ingredients into a ball of dough on the countertop. When this was done, my parents had to pass the responsibility of making their wonderful baked goods onto someone, or, rather something else, aka the oven. What exactly happened during the twelve minutes when my dad’s goopy batter turned into gorgeous and tasty blueberry muffins? What does that oven do to my mother’s dough that makes it mouth-watering chewy Anadama bread? What exactly happens when you bake anything?
The first key to baking is truly the ingredients. Baking recipes call for certain ingredients in specific amounts, and they are usually this way for a reason! What ingredients you use, as well as their ratios, can either make or break a baked-good. Different ingredients will have different effects on the final product. Some ingredients can strengthen, give structure to, tenderize, moisten, dry out, or leaven anything that you bake. For example, an ingredient like flour provides protein (that coagulate w/ heat) and starch (that gelatinize w/ heat) which give the final product strength and structure. Fats like butter will tenderize a structure and moisten any treat by lubricating proteins and starches. Ingredients like milk or water will provide moisture. Sugars also provide moisture to baked goods in addition to a sweet flavor. Different ingredients like extracts are usually used only for their flavors. Last, but certainly not least, would be the most important ingredient of all, leaveners.
Leaveners create bubbles, or air pockets, throughout the structure of a baked good, allowing it to rise. There are several different kinds of leaveners: physical, biological, chemical, and steam. Physical leaveners include the methods used to combine or work ingredients together. These methods include whipping, creaming, and kneading. These different methods allow people to physically leaven, add air bubbles to, their different mixtures (batters, dough, etc.), which will allow for better rising later. In the method known as “creaming,” you rapidly mix together butter and sugars until they are smooth. The sugar granules are small and sharp, so they actually slice holes into the butter. This creates an area for air to be trapped within the fats in the butter. Creaming is often used when you’re making cookies. With the kneading method, dough is usually made (aka, pizza dough or bread). The dough is repeatedly pushed (with the lower palm of the hand) and folded back on itself. Kneading serves several purposes in baking. The act of kneading, incorporation of air into the dough by folding and pushing, is very important. It creates seed bubbles which will not only allow the dough to rise while baking, but which will also allow other leaveners, like yeast, which will soon be explained, to help the dough rise while resting.
This brings us to biological leaveners, like the yeasts mentioned above. You know that tangy smell that hits you when perhaps you or your friends are drinking a beer or eating a slice of homemade bread? That smell is yeast. And guess what? IT’S ALIIIIVE! But it won’t hurt you! Yeast devours sugars. By adding yeast to dough with sugars, it releases products like ethanol and CO2 gas, as well as a host of other flavors. Yeast makes bread dough rise because of the gas it gives off. It can’t make the bread rise on its own, however. It needs the physically incorporated seed bubbles discussed earlier in the physical method of kneading. These bubbles fill with the gas released by the yeast, which gets trapped, making the bread rise!
There are two other kinds of leaveners, chemical and steam. The act of chemical leavening occurs when a base and an acid are mixed together in the presence of water. This combination creates a neutral salt and also gives off a gas, CO2, which gets trapped throughout the seed bubbles in the dough, allowing it to rise while baking. You can buy an acid-base mixture for baking at your local grocery store. It’s a common product composed of a mixture of baking soda (a base) and cream of tartar (an acid) that you’ve probably used numerous times before- baking powder! Similarly, different liquids that contain water like eggs and milk, or even just water itself, create water vapor, or steam, which also helps expand the volume of a baked-good.
Now that the different ingredients have been discussed, let’s discuss what happens when you heat doughs and batters. When raw, doughs and batters may appear to be or even taste inedible. After heating they transform into gorgeous tasty treats of all sorts of flavors and textures. What, on a chemical level, happens during heating that creates this transformation? Heat causes the following to occur: water evaporates creating steam which can act as a leavener, proteins denature and coagulate creating structure, starches gel giving more structure fats melt creating moisture, the yeasts that once produced CO2 and ethanol dies, and the Maillard reaction takes place producing brown colors and delicious flavors. Without heat, these processes wouldn’t occur, and baked-goods would remain a goopy mess!
There is one important aspect to baking that has yet to be mentioned, and it concerns gluten! Gluten is a word people are hearing more and more often recently when discussing diet due to the rise of Celiac disease, which is, at its essence, a gluten allergy. But what is gluten and why is it so important to baking? You can find gluten in various food products, but it is primarily present in flour. It is composed of two proteins, glutenin and gliadin. When you add water to flour, these proteins bond to each other and to water molecules. If you continue to mix or knead the flour and water, the proteins will continue to connect until sheets of gluten form, which help trap air allowing doughs to rise. This is why pizza dough needs to be kneaded so much before it rests; lots of gluten sheets need to be formed (as well as seed bubbles) so that the gases from the yeast get trapped and the dough expands. The protein content and physical properties of flour relate to gluten: the more gluten-forming proteins there are in the flour, the more liquid the flour will absorb. Therefore, different flours have different purposes. For example, according to Shirley Corriher on page 6 of her book Cookwise the Secrets of Cooking Revealed, bleached southern all-purpose flour (with a protein content of 9) is best for pie crusts, biscuits, and muffins, whereas bread flour is best for yeast breads, pasta, or pizza. Gluten creates a strong, but elastic structure. Where it’s essential for baked-goods like loaves of bread, large amounts of gluten would be detrimental to cakes, which are typically light and fluffy.