| Strengtheners Wheat flours and egg whites contain proteins that provide strength and structure for a batter so it will rise and not collapse when baked. Wheat is the only grain with significant amounts of gluten-forming potential. Other grains like corn and oats do not create gluten in a batter. They provide only flavor and bulk, and must be mixed with wheat flour for strength. There are as many as 30 different types of protein in wheat, but only two, glutenin and gliadin, form an elastic substance known as gluten when combined with water. When wheat flour is moistened and stirred, two proteins in the flour, glutenin and gliadin, grab water and connect and cross-connect to form elastic strands of gluten, which help give structure to the baked good. Gluten gives a framework to a baked good by swelling as they absorb water, some flour types absorbing faster than others. Gluten becomes rigid as the moisture evaporates from the heat of the oven, and sets the baked goods' structure. They also trap the tiny air cells created from mixing, creaming, kneading or stirring, which later expand from the leavening and the heat of the oven. Gluten provides the elasticity of dough and also makes it plastic or moldable. This resulting gluten then traps the gas bubbles produced by fermentation. Their "development" consists of the formation of these bonds. Breads rely heavily on gluten for structure, cakes to a lesser extent, and cookies almost not at all. The greater the amount of gluten developed, the "stronger" the leavening needs to be. Chemical leavening, such as baking powder and baking soda, are used in cakes, muffins, and biscuits, which all have a moderate gluten structure. Leavening in yeast bread products need a strong gluten structure, as bread dough has to withstand the leavening power of yeast, sometimes over a few hours. When flour is milled, it is classified according to the ratio of its gluten forming proteins to starch. The protein content of a flour affects the strength of a dough. Depending on the type of wheat and where and when it was planted, the resulting flour can be high-gluten (milled from hard winter wheat), low-gluten (from soft spring wheat), or moderate (a combination of the two). Baked goods made from high-gluten flours have a firm crumb; low-gluten flours give more tender results, and goods made from flours with a moderate gluten content fall somewhere in between The more that the flour and moisture are stirred or handled, the more the gluten strands strengthen and toughen. Fat, plays an important role in coating the proteins in flour, minimizing their contact with moisture, and shortening the gluten's development. Without the fat lubricator, the gluten strands form more readily. Many ingredients also do the job of interfering with gluten's development. For example, butter and shortening coat the flour strands and prevent moisture from reaching them, while sugar acts as a tenderizer because it attracts water away from the proteins in the flour Recipes commonly use all-purpose flour, which has a moderate gluten or protein content. High-gluten flours, such as bread and regular whole wheat, as well as a moderate one, all-purpose, are typically used in yeast breads where a strong framework is desirable. But, in cakes, quick breads and pastries, a high protein flour makes a tough baked good Shorteners Most bakers are very familiar with traditional shorteners such as butter, margarine or vegetable shortening. Shorteners coat the flour proteins or water-proof them, contributing to tender baking recipe by reducing their contact with the moisture in the recipe and preventing gluten from forming. They also shorten the length of the gluten strands when the flour is stirred with that moisture preventing a tough baked good. In traditional baking, where solid fats are creamed with crystalline sugar, tiny air cells are incorporated into the batter, so the baked good will have a fine, aerated texture. When a shortener is removed or reduced, it increases the chances that the end product will lack flavor and be tough and full of tunnels. Different types of fat do different jobs. Butter makes an important flavor contribution, whereas margarine does not have as fine a texture and taste. Fat can be found in other baking ingredients, such as the egg yolk which serves as both a tenderizer and emulsifier due to its fat and lecithin content. Oils do not act as a shortener because it is a liquid and won't cream with crystalline sugar in the same way that solid fat does. Oils tend to coat each particle of flour, which causes a lack of contact of moisture and helps prevent gluten development. It reduces dryness and enhances flavor. Fat Substitutes Fruit purees, especially applesauce, are often used as fat substitutes. The pectin from the fruit forms a film around the tiny air bubbles in the batter, similar to what occurs when you cream solid shortenings with sugar, but not as effectively. Other fat substitutes include pumpkin, banana, and prune purees Sugar is an important and versatile food ingredient in baking recipes, other than merely providing sweetness and flavor. It tendarizes dough and batters, by competing for water with flour and grabs it faster thus inhibiting gluten formation, which makes baked goods tender. It also helps brown baked products and also assists in retaining moisture in the baked good, preventing the staleness that we notice when these foods dry out. It is used as a preservative as in the case of jams and jellies and is a food source for yeast and vital for fermentation. It is integral in the creaming process that incorporates air into the batter and is used to prevent large ice crystals from forming in frozen sweet mixtures, like ice cream and enhances texture and colours Liquids Liquid in a recipe may be milk, water, fruit juices, potato water and even eggs. The amount of liquid determines whether a "dough" or "batter" is produced. Liquids also serve to hydrate the flour, for gluten formation, and to hydrate the starch, for gelatinizing, which results in formation of the basic structure of a baked product. Liquids also dissolve the sugar and salt, making possible the leavening action of baking powder, soda and acid, or growth of yeast. It also helps to aerate the batter or dough from the steam created when baked Leaveners The three basic leavening gases commonly found in baking recipes are air from whipped eggs, or beating, stirring, creaming and kneading; water vapor or steam from liquids; carbon dioxide from chemical leaveners, baking soda and baking powder; and yeast, both packaged and from a starter (sourdough or sponge). In many baked items, all three of these agents participate in the leavening process. A leavening agent provides a source of gas to the recipe called carbon dioxide. When moistened, fermented and/or heated, it expands the millions of air bubbles previously created in a batter or dough from mixing, creaming, beating, folding, whipping and kneading trapped in the structural framework by the gluten strands. If the batter is over mixed or not baked promptly, the gas will escape and the final recipe will have poor texture and low volume. During mixing, some air is always incorporated. Although it is usually not the major leaven, it plays an important role. Beaten eggs aerate recipes due to their ability to foam and by contributing water for steam, such as with sponge or angel food cakes. A foam is created by incorporating air into a mixture through "beating". Whole eggs, egg whites or egg yolks can each be beaten into a foam, with whites having the potential of producing the most. Air is also incorporated into cakes when fat and sugar are beaten together. Steam is produced when water, in the recipe, is heated to 212 degrees F by baking. Most batter recipes are to some degree leavened by steam. To get maximum steam production in a system, a 1:1 ratio of liquid to flour is needed, which recipes already have. As the amount of water relative to flour decreases, less leavening from steam occurs. In steam-leavened products, the changes that occur in the volume occur at the end of the baking cycle. Popovers are a good example of the rapid volume expansion which leavens a product late in the baking period. Chemical leaveners include baking soda (bicarbonate of soda) which produces carbon dioxide gas when moistened and/or heated. They are alkaline, and when they comes in contact with an acidic ingredient like applesauce, buttermilk, honey, brown sugar, molasses and lemon juice, the alkali/acid combination creates carbon dioxide. In some recipes, depending on the quantity of acidic ingredients included, a combination of baking soda and baking powder is used for better flavor and texture. Baking powder, another chemical leavener, does not need an acidic ingredient to release its leavening power. Double-acting baking powder begins releasing carbon dioxide as soon as it is moistened, and again when heated in the oven. Yeast, used in bread baking, is either packaged or created through a sourdough or sponge starter. Yeast, a single-celled live organism, feeds off of the flour's starches and sugars, moistened by liquid, usually water, fermenting it to carbon dioxide and ethanol (alcohol). Carbon dioxide is the primary leavening gas that makes yeast breads rise. The alcohol evaporates during baking, leaving behind flavor Thickeners Not every recipe includes a thickener, although flour certainly has thickening attributes. But many fruit fillings include cornstarch to thicken the juices. I occasionally use tapioca as a thickener, as well. Eggs are used as thickeners and are used in such recipes as custards, puddings and sauces Flavourings Flavorings enhance a baked good's aroma and taste. Salt, sugar or an acidic ingredient, such as buttermilk, cocoa powder or lemon juice, are the three most important ones used to give interest to a recipe (a wide variety of flavorings and other ingredients add greatly to a recipe, too). In addition to being used as a flavoring, salt functions to control yeast metabolism in yeast bread. Butter also plays an important flavoring role. The butter in traditional recipes contributes to and carries flavors throughout the batter. Even more important, butter has flavor of its own that, when it interacts with sugar, is responsible for the caramelized baked taste we associate with baked goods. In reduced-fat baking, the flavorings must be increased to compensate for the reduction in butter |
