OK, so it is not a new idea, but the amount of each ingredient used to bake certain items is often a precisely calculated amount through huge samples of trial and error, and it is important to take every ingredient into consideration. This is also NOT to say that every recipe is perfect which is why it is important to understand the basic purpose of most ingredients utilized commonly in baking.
Ideally, after reading this article you should know what the difference between baking powder and baking soda is, why you sift sometimes but not others, and perhaps be on your way to perfecting your grandmothers age-old zucchini-bread recipe.
HOWEVER, if you are like me and your mentality is, a little extra there, a little less here, and you tend to just go with the flow of your food production, perhaps you should 86 the baking, and stick with regular old cooking, which is less like Chemisty and more like Genetics in my opinion.
YOUR COMMON PROCESSES AND INGREDIENTS
Baking Soda, or sodium bicarbonate, often serves two purposes when baking. On the one hand, it serves neutralize the pH of other acidic ingredients, and keeps your baked goods from tasting too tart, but by the same token it reacts with acids in a way that causes it tobecome a leavening agent. I am sure everyone has done the classic vinegar/baking soda volcano experiment in their early age.
Essentially, in controlled amounts it works the same way in your baked goods to create bubbles of carbon-dioxide gas which create the so-called “crumb” of your baked good. Another fun-fact is that when mixed with cocoa powder in baked goods, it can cause the powder to take on a sort of reddish hue, as it does in some chocolate cakes.
Baking POWDER is different from baking-soda in that it IS baking-soda, but with a few other friends. Baking powder usually has dry acid-salts or other acidic components mixed into the powder with a bit of corn-starch so that while dry it is inactive, but once mixed with any kind of moisture it immediately begins to cause leavening. Baking powder that is double action works in two ways. First, the moisture activated leavening occurs, THEN the heat from the baking process causes gas-bubbles from leavening to expand. But, it is important to remember that if you modify a recipe to include two much baking-powder it is possible for over-leavening to occur, which usually results in a collapse. (Ever seen a cartoon or movie where the Chef works hard on the souffle, and then it deflates?)
Yeast work much in the same way as baking-powder or soda only with a different chemical process. The process is fermentation. The yeast convert sugars, starches carbohydrates etc. in the dough or batter into alcohol, and a resulting byproduct is carbon-dioxide gas. Thus, for yeast to be effective the dough must have some sugar, or carbohydrate content.
Baking-soda and powder are the primary cause requiring the sifting of dry ingredients. Before liquids are added, the baking-soda and powder is inactive, and thus while you are able you should ensure that the dry ingredients are completely uniform. THIS is why you sift. If you don’t, it is possible that you could have a chunk of baking powder stuck somewhere in there that causes a gargantuan air-bubble to occur, thereby ruining the crumb of your baked goods.
Flour is the most commonly found ingredient in baked goods….obviously. What does it DO, though? Flour obviously adds mass to whatever you are trying to bake, but the essential aspect of modern flour is gluten. Gluten is a protein created by adding moisture to flour, and is what gives your baked goods strength and structure. Gluten acts like a net collecting and holding the air-bubbles created by leavening agents, and enables your baked goods to rise, set, and ultimately maintain any type of structure.
This brings us to the next point. Why are there different types of flours? You may have seen, while at the grocery store, that there are: all-purpose flour, cake flour, bread flour, pastry flour, and an array in between. Different types of flour have different levels of gluten.
General all-purpose has a moderate amount, while cake and pastry flours have less. Bread flours have the most. Adding too much gluten to a recipe can cause it to become tough, and not let air bubbles expand the way they should, whereas too little gluten can cause your recipe to collapse. Further, flour also has large amounts of starch which, when mixed with moisture, becomes gelatinous. For this reason, choosing the right flour can be important. If you try and cook bread with cake flour, your bread will require more gluten, and therefore more flour, but too much flour and the starches will cause your bread crumb and texture to be gelatinous and unappealing. Gluten is also MOST essential to pastries requiring thin dough because gluten allows the dough to be rolled very thinly while maintaining structure.
Many baked goods call for egg-whites, usually whipped. Egg whites work similar to gluten in that once cooked, the heat denatured proteins create a framework of structure. However, egg-whites, especially when beaten, will be strong but cause the baked good to have a spongy texture (e.g. angel-food cake).
The primary purpose of shortening (shortening means solid fats such as butter) is to tenderize and at times decrease the degree of leavening in the baked good. When added to flour and mixed together, shortening coats flour and reduces the exposure of flour to water which prevents longer strands of gluten from forming. In this way it keeps the baked good from becoming too, for a lack of a better word “gluteny”, and keeps the baked good more tender. It also makes the gluten strand framework that results more slippery, letting some air-bubbles escape and thereby keeping the crumb/grain of the baked good much finer.
Oil works very similarly to shortening except that because it is a liquid, it can at times completely coat flour particles and prevent the creation of too much gluten as opposed to only limiting the size and strength of the strands. This allows much more moisture to be retained in the baked good, instead of acting as a chemical agent in the production of gluten, and will result in a more moist baked good.
SWEETENERS AND SUGAR
Sugars are entirely too complicated, and you probably shouldn’t worry too much about it in college baking. BUT for the more curious individual refer below.
For a complete rundown of sugars refer to: Joy of Baking