BAKING

process of cooking by dry heat, especially in some kind of oven. It is probably the oldest cooking method. Bakery products, which include bread, rolls, cookies, pies, pastries, and muffins, are usually prepared from flour or meal derived from some form of grain. Bread, already a common staple in prehistoric times, provides many nutrients in the human diet. process of cooking by dry heat, especially in some kind of oven. Bakery products comprise a wide variety of foods, including bread, rolls, cookies, pies, pastries, and muffins. Baking dates, in its most rudimentary form, to prehistoric times. At first it involved nothing more than the simple drying of grain seeds in the sun. Eventually the seeds came to be cooked in water, and the resulting gruel was baked on a hot stone, producing a kind of flat bread that was in many ways similar to the Mexican tortilla. The process of leaveningthat is, making bread lighter, thicker, and more flavourfuldeveloped slowly. The Egyptians, it is believed, were the first to consciously use leavening in their baking and also were the first to use ovens. By the middle of the 3rd century BC, the Egyptians had developed baking methods that were similar in many ways to those in use today. During the centuries following, no major advances in baking methods were made, although the Romans introduced some minor technological improvements. Only with the Industrial Revolution of the mid-19th century did the technology of baking begin to advance rapidly. The quality of ingredients improved, and automation began to replace the time-consuming manual process; both developments led to the establishment of a baking industry that in the 20th century produces a wide variety of goods with highly elaborate and efficient machinery. While some baked products are still unleavened (such as pie crusts, Mexican tortillas, and the similar chapatis from India), many modern baked goods employ leavening, which is central to both their taste and their texture. Only wheat and rye flours have the qualities necessary for the expansion of an initial dough or batter, and wheat is more satisfactory. Although various flours are used in baking, some amount of wheat flour must be added if any significant degree of leavening is desired. Protein in the flour, known as gluten, combines with water to produce an elastic and porous web capable of trapping gas bubbles released by the action of a leavening agent. In bread and in some other sweeter rolls and pastries, baker's yeast (composed of living cells of the Saccharomyces cerevisiae yeast strain) is used to create the leaven. It ferments sugars present in the flour and in other ingredients, giving off carbon dioxide and ethanol. Another leavening method is the use of sourdough, a type of dough that contains an acid-generating bacteria that ferments the sugars. Sourdough has a distinctive flavour and is often used in the making of rye bread. Salt-rising bread, with its sharp odour and taste, uses both yeast and sourdough as fermenting agents. Such sweeter bakery products as layer cakes, biscuits, cookies, and muffins make use of chemical reactions rather than fermentation for leaven. Sodium bicarbonate (baking soda) is most commonly used, but it must be properly combined with counteracting acids in order to release a sufficient amount of carbon dioxide. Such a combination is provided in baking powder, whose formula also serves to regulate the timing of the gas's release. These bakery products generally employ a softer flour, containing less gluten than that used in yeast-leavened goods. Thus, the dough is not able to trap as much gas, and these products are generally denser. Another important method of leavening batters is the mixing in of air bubbles from the outside atmosphere. This can be accomplished only by the inclusion of an ingredient (often egg whites) that can easily be beaten into a foam that can hold air bubbles. This method produces a particularly light and delicate product (for example, angel food or sponge cake). Important ingredients for baking other than flour, water, and leavening agents are shortening (fats, butter, oils, lard), eggs, milk, and sugars. Shortening tends to make doughs more easily workable and the final product tenderer, while also, in many cases, adding flavour. Egg whites, as mentioned, are often used to produce a light, airy texture, and yolks contribute to the colour, flavour, and texture of baked products. Milk is used for flavouring, and sugars to sweeten and to aid fermentation. Commercial bakeries employ a variety of techniques ranging from the use of simple home baking methods by smaller companies to the use of highly complex and automated equipment in large commercial operations. Even in many larger bakeries, however, the basic steps of baking in batches remain the same; the ingredients are simply used in much larger quantities. Measured accurately by computers, the ingredients are first mixed into dough or batter, sometimes in large horizontal machines with revolving bars that work the mixture into a uniform structure, and other times in giant mixing bowls similar, except in size, to those found in the home. With yeast-leavened goods, mixing is often done in two stages, permitting an interim period of fermentation and a chance for more control over the variability that some ingredients exhibit from batch to batch. When the ingredients are mixed (and, in the case of yeast leavening, the dough properly fermented), an elaborate series of machines that vary with the product separate and shape the dough or batter into individual units and prepare these for final baking. The batch is then placed in an oven and cooked to specifications. Continuous baking, an alternative to the batch method, substitutes a steady flow of dough or batter through processing machines in place of the discrete amount of mixtures handled in batches. The ingredients are mixed and fermented in a liquid or semiliquid state and are then cooled into a continuous piece of dough or stream of batter. This is pushed out through an opening of the mixing machine at a steady rate and is sliced into uniform pieces, or it is poured into standardized containers and passed slowly on a conveyer belt through an open-ended oven. Additional reading R. MacRae, R.K. Robinson, and M.J. Sadler (eds.), Encyclopaedia of Food Science, Food Technology, and Nutrition, 8 vol. (1993); and Y.H. Hui (ed.), Encyclopedia of Food Science and Technology, 4 vol. (1992), are general works that cover all aspects of the science of food. P. Fellows, Food Processing Technology: Principles and Practices (1988), is an introductory text. R. Paul SinghVarious aspects of baking are treated in books by Samuel A. Matz: Ingredients for Bakers (1987), containing descriptions of the raw materials used by bakers, Formulas and Processes for Bakers (1987), presenting guidelines used in formulating doughs and batters, examples of many typical formulas, explanations of changes occurring in mixing, fermenting, shaping, and cooking, and the effects that processing variables may have on the quality of the finished product, Equipment for Bakers (1988), discussing the different machines used in retail and wholesale bakeries, including the specifications and functions of individual models, Bakery Technology: Packaging, Nutrition, Product Development, QA (1989), and Cookie and Cracker Technology, 3rd ed. (1992). Additional works include E.J. Pyler, Baking Science & Technology, 3rd ed., 2 vol. (1988); William J. Sultan, Practical Baking, 5th ed. (1990), a survey of the art and craft of professional baking; and D.J.R. Manley, Technology of Biscuits, Crackers, and Cookies, 2nd ed. (1991).A more fundamental approach to some of the problems in baking science can be found in Hamed A. Faridi and Jon M. Faubion (eds.), Dough Rheology and Baked Product Texture (1990). Samuel A. Matz