Bread

Bread is a staple food prepared by baking a dough of flour and water and often additional ingredients, such as butter or salt to improve the taste.
==Types==
Bread is the staple food in Europe, European-derived cultures such as the Americas, and the Middle East and North Africa, as opposed to East Asia whose staple is rice. Bread is usually made from a wheat-flour dough that is cultured with yeast, allowed to rise, and finally baked in an oven. Owing to its high levels of gluten (which give the dough sponginess and elasticity), common wheat (also known as bread wheat) is the most common grain used for the preparation of bread.
Bread is also made from the flour of other wheat species (including durum, spelt and emmer), rye, barley, maize (corn), and oats, usually, but not always, in combination with wheat flour. Spelt bread (Dinkelbrot) continues to be widely consumed in Germany, and emmer bread was a staple food in ancient Egypt. Canadian bread is known for its heartier consistency due to high protein levels in Canadian flour.
*White bread is made from flour containing only the central core of the grain (endosperm).
*Brown bread is made with endosperm and 10% bran. It can also refer to white bread with added colouring (often caramel colouring) to make it brown; this is commonly labeled in America as wheat bread (as opposed to whole-wheat bread).
*Wholemeal bread contains the whole of the wheat grain (endosperm, bran, and germ). It is also referred to as "whole-grain" or "whole-wheat bread", especially in North America.
*Wheat germ bread has added wheat germ for flavoring.
*Whole-grain bread can refer to the same as wholemeal bread, or to white bread with added whole grains to increase its fibre content, as in "60% whole-grain bread".
*Roti is a whole-wheat-based bread eaten in South Asia. Chapatti is a larger variant of roti. Naan is a leavened equivalent to these.
*Granary bread is made from flaked wheat grains and white or brown flour. The standard malting process is modified to maximise the maltose or sugar content but minimise residual alpha amylase content. Other flavour components are imparted from partial fermentation due to the particular malting process used and to Maillard reactions on flaking and toasting.
*Rye bread is made with flour from rye grain of varying levels. It is higher in fiber than many common types of bread and is often darker in color and stronger in flavor. It is popular in Scandinavia, Germany, Finland, the Baltic States, and Russia.
*Unleavened bread or matzo, used for the Jewish feast of Passover, does not include yeast, so it does not rise.
*Sourdough bread is made with a starter.
*Flatbread is often simple, made with flour, water, and salt, and then formed into flattened dough; most are unleavened, made without yeast or sourdough culture, though some are made with yeast.
*Crisp bread is a flat and dry type of bread or cracker, containing mostly rye flour.
*Hemp bread includes strongly-flavored hemp flour or seeds. Considered one of the "superior elixirs of immortality," hemp has been used for thousands of years in Traditional Chinese Medicine. Hemp flour is the by-product from pressing the oil from the seeds and milling the residue. It is perishable and stores best in the freezer. Hemp dough won't rise due to its lack of gluten, and for that reason it is best mixed with other flours. A 5:1 ratio of wheat-to-hemp flour produces a hearty, nutritious loaf high in protein and essential fatty acids. Hemp seeds have a relatively high oil content of 25-35%, and can be added at a rate up to 15% of the wheat flour. The oil's omega-6-to-omega-3 ratio lies in the range of 2:1-to-3:1, which is considered ideal for human nutrition.
===Quick breads===
The term quick bread usually refers to a bread chemically leavened, usually with both baking powder and baking soda, and a balance of acidic ingredients and alkaline ingredients. Examples include pancakes and waffles, muffins and carrot cake, Boston brown bread, and zucchini and banana bread.
==Bread making==
Doughs are usually baked, but in some cuisines breads are steamed (e.g., mantou), fried (e.g., puri), or baked on an unoiled frying pan (e.g., tortillas). It may be leavened or unleavened (e.g. matzo). Salt, fat and leavening agents such as yeast and baking soda are common ingredients, though bread may contain other ingredients, such as milk, egg, sugar, spice, fruit (such as raisins), vegetables (such as onion), nuts (such as walnuts) or seeds (such as poppy). Referred to colloquially as the "staff of life", bread has been prepared for at least 30,000 years. The development of leavened bread can probably also be traced to prehistoric times. Sometimes, the word bread refers to a sweetened loaf cake, often containing appealing ingredients like dried fruit, chocolate chips, nuts or spices, such as pumpkin bread, banana bread or gingerbread.
Fresh bread is prized for its taste, aroma, quality, appearance and texture. Retaining its freshness is important to keep it appetizing. Bread that has stiffened or dried past its prime is said to be stale. Modern bread is sometimes wrapped in paper or plastic film or stored in a container such as a breadbox to reduce drying. Bread that is kept in warm, moist environments is prone to the growth of mold. Bread kept at low temperatures, in a refrigerator for example, will develop mold growth more slowly than bread kept at room temperature, but will turn stale quickly due to retrogradation.
The soft, inner part of bread is known to bakers and other culinary professionals as the crumb, which is not to be confused with small bits of bread that often fall off, called crumbs. The outer hard portion of bread is called the crust.
===Formulation===
Professional baker recipes are stated using a notation called baker's percentage. The amount of flour is denoted to be 100%, and the amounts of the other ingredients are expressed as a percentage of that amount by weight. Measurement by weight is more accurate and consistent than measurement by volume, particularly for dry ingredients.
The proportion of water to flour is the most important measurement in a bread recipe, as it affects texture and crumb the most. Hard US wheat flours absorb about 62% water, while softer wheat flours absorb about 56%. Common table breads made from these doughs result in a finely textured, light bread. Most artisan bread formulas contain anywhere from 60 to 75% water. In yeast breads, the higher water percentages result in more CO2 bubbles and a coarser bread crumb. One pound (450 g) of flour will yield a standard loaf of bread or two French loaves.
Calcium propionate is commonly added by commercial bakeries to retard the growth of molds.
===Flour===
Flour is a product made from grain that has been ground to a powdery consistency. Flour provides the primary structure to the final baked bread. While wheat flour is most commonly used for breads, flours made from rye, barley, maize, and other grains are also commonly available. Each of these grains provides the starch and protein needed to form bread.
The protein content of the flour is the best indicator of the quality of the bread dough and the finished bread. While bread can be made from all-purpose wheat flour, a specialty bread flour, containing more protein (12-14%), is recommended for high-quality bread. If one uses a flour with a lower protein content (9–11%) to produce bread, a shorter mixing time will be required to develop gluten strength properly. An extended mixing time leads to oxidization of the dough, which gives the finished product a whiter crumb, instead of the cream color preferred by most artisan bakers.
Wheat flour, in addition to its starch, contains three water-soluble protein groups (albumin, globulin, and proteoses) and two water-insoluble protein groups (glutenin and gliadin). When flour is mixed with water, the water-soluble proteins dissolve, leaving the glutenin and gliadin to form the structure of the resulting bread. When relatively dry dough is worked by kneading, or wet dough is allowed to rise for a long time (see no-knead bread), the glutenin forms strands of long, thin, chainlike molecules, while the shorter gliadin forms bridges between the strands of glutenin. The resulting networks of strands produced by these two proteins are known as gluten. Gluten development improves if the dough is allowed to autolyse.
===Liquids===
Water, or some other liquid, is used to form the flour into a paste or dough. The weight of liquid required varies between recipes, but a ratio of 3 parts liquid to 5 parts flour is common for yeast breads. Recipes that use steam as the primary leavening method may have a liquid content in excess of 1 part liquid to 1 part flour. Instead of water, other types of liquids, such as dairy products, fruit juices, or beer, may be used; they contribute additional sweeteners, fats, or leavening components, as well as water.
===Leavening===
Leavening is the process of adding gas to a dough before or during baking to produce a lighter, more easily chewed bread. Most bread consumed in the West is leavened. Unleavened breads have symbolic importance in Judaism and Christianity. Jews consume unleavened bread called matzo during Passover. Roman Catholic and some Protestant Christians consume unleavened bread during the Christian liturgy when they celebrate the Eucharist, a rite derived from the narrative of the Last Supper when Jesus broke bread with his disciples, perhaps during a Passover Seder. In contrast, Orthodox Christians always use leavened bread during their liturgy.
====Chemical leavening====
A simple technique for leavening bread is the use of gas-producing chemicals. There are two common methods. The first is to use baking powder or a self-rising flour that includes baking powder. The second is to include an acidic ingredient such as buttermilk and add baking soda; the reaction of the acid with the soda produces gas.
Chemically leavened breads are called quick breads and soda breads. This method is commonly used to make muffins, pancakes, American-style biscuits, and quick breads such as banana bread.
====Yeast====
Many breads are leavened by yeast. The yeast most commonly used for leavening bread is Saccharomyces cerevisiae, the same species used for brewing alcoholic beverages. This yeast ferments some of the carbohydrates in the flour, including any sugar, producing carbon dioxide. Most bakers in the U.S. leaven their dough with commercially produced baker's yeast. Baker's yeast has the advantage of producing uniform, quick, and reliable results, because it is obtained from a pure culture. Many artisan bakers produce their own yeast by preparing a growth culture that they then use in the making of bread. When this culture is kept in the right conditions, it will continue to grow and provide leavening for many years.
Both the baker's yeast and the sourdough methods of baking bread follow the same pattern. Water is mixed with flour, salt and the leavening agent (baker's yeast or sourdough starter). Other additions (spices, herbs, fats, seeds, fruit, etc.) are not needed to bake bread, but are often used. The mixed dough is then allowed to rise one or more times (a longer rising time results in more flavor, so bakers often "punch down" the dough and let it rise again), then loaves are formed, and (after an optional final rising time) the bread is baked in an oven.
Many breads are made from a "straight dough", which means that all of the ingredients are combined in one step, and the dough is baked after the rising time; others are made from a "pre-ferment" in which the leavening agent is combined with some of the flour and water a day or so ahead of baking and allowed to ferment overnight. On the day of the baking, the rest of the ingredients are added, and process continues as with straight dough. This produces a more flavorful bread with better texture.
Many bakers see the starter method as a compromise between the highly reliable results of baker's yeast and the flavor and complexity of a longer fermentation. It also allows the baker to use only a minimal amount of baker's yeast, which was scarce and expensive when it first became available. Most yeasted pre-ferments fall into one of three categories: "poolish" or "pouliche", a loose-textured mixture composed of roughly equal amounts of flour and water (by weight); "biga", a stiff mixture with a higher proportion of flour; and "pâte fermentée", which is simply a portion of dough reserved from a previous batch. Sourdough (also known as "levain" or "natural leaven") takes the pre-ferment method a step further, mixing flour and water to allow naturally occurring yeast and bacteria to propagate (usually Saccharomyces exiguus, which is more acid-tolerant than S. cerevisiae and various species of Lactobacillus).
====Sourdough====
Sourdough is a type of bread produced by a long fermentation of dough using naturally occurring yeasts and lactobacilli. In comparison with breads made with cultivated yeast, it usually has a mildly sour taste because of the lactic acid produced by the lactobacilli.
Sourdough breads are made with a sourdough starter (which differs from starters made with baker's yeast). The starter cultivates yeast and lactobacilli in a mixture of flour and water, making use of the microorganisms already present on flour; it does not need any added yeast. A starter may be maintained indefinitely by regular additions of flour and water. Some bakers have starters several generations old, which are said to have a special taste or texture. It is possible to obtain existing starter cultures to begin a new one.
At one time, all yeast-leavened breads were sourdoughs. The leavening process was not understood until the 19th century, when yeast was first identified. Since then, strains of Saccaromyces cerevisiae have been bred for their reliability and speed of leavening and sold as "baker's yeast". Baker's yeast was adopted for the simpicity and flexibility it introduced to bread making, obviating the lengthy cultivation of a sourdough starter. While sourdough breads survived in some parts of Europe, throughout most of the U.S., they were replaced by baker's yeast. Recently there has been a revival of sourdough bread in artisan bakeries.
There are other ways of sourdough baking and culture maintenance. A more traditional one is the process that was followed by peasant families throughout Europe in past centuries. The family (usually the woman was in charge of breadmaking) would bake on a fixed schedule, perhaps once a week. The starter was saved from the previous week's dough. The starter was mixed with the new ingredients, the dough was left to rise, and then a piece of it was saved (to be the starter for next week's bread). The rest was formed into loaves that were marked with the family sign (this is where today's decorative slashing of bread loaves originates from) and taken to the communal oven to bake. These communal ovens with time evolved into the modern bakery.
====Steam====
The rapid expansion of steam produced during baking leavens the bread, which is as simple as it is unpredictable. The best known steam-leavened bread is the popover. Steam-leavening is unpredictable since the steam is not produced until the bread is baked.
Steam leavening happens regardless of the rising agents (baking soda, yeast, baking powder, sour dough, beaten egg whites, etc.).
* The leavening agent either contains air bubbles or generates carbon dioxide.
* The heat vaporises the water from the inner surface of the bubbles within the dough.
* The steam expands and makes the bread rise.
This is the main factor in the rise of bread once it has been put in the oven. CO2 generation, on its own, is too small to account for the rise. Heat kills bacteria or yeast at an early stage, so the CO2 generation is stopped.
====Bacteria====
Salt rising bread employs a form of bacterial leavening that does not require yeast. Although the leavening action is not always consistent, and requires close attention to the incubating conditions, this bread is making a comeback due to its unique cheese-like flavor and fine texture.
====Aeration====
Aerated bread is leavened by carbon dioxide being forced into dough under pressure. The technique is no longer in common use, but from the mid 19th to 20th centuries bread made this way was somewhat popular in the United Kingdom, made by the Aerated Bread Company and sold in its high-street tearooms.
===Fats or shortenings===
Fats, such as butter, vegetable oils, lard, or that contained in eggs, affect the development of gluten in breads by coating and lubricating the individual strands of protein. They also help to hold the structure together. If too much fat is included in a bread dough, the lubrication effect will cause the protein structures to divide. A fat content of approximately 3% by weight is the concentration that will produce the greatest leavening action. In addition to their effects on leavening, fats also serve to tenderize breads and preserve freshness.
===Bread improvers===
Bread improvers are often used in producing commercial breads to reduce the time needed for rising and to improve texture and volume. Chemical substances commonly used as bread improvers include ascorbic acid, hydrochloride, sodium metabisulfate, ammonium chloride, various phosphates, amylase, and protease.
Salt is one of the most common additives used in production. In addition to enhancing flavor and restricting yeast activity, salt affects the crumb and the overall texture by stabilizing and strengthening<ref>Nancy Silverton, Breads From The La Brea Bakery (1996), Villard and is done with both refined and whole-grain flours.
===Chemical composition===
In wheat, phenolic compounds are mainly found in hulls in the form of insoluble bound ferulic acid where it is relevant to wheat resistance to fungal diseases.
Rye bread contains phenolic acids and ferulic acid dehydrodimers.
Three natural phenolic glucosides, secoisolariciresinol diglucoside, p-coumaric acid glucoside and ferulic acid glucoside, can be found in commercial breads containingflaxseed.
==Serving and consumption==
Bread can be served at any temperature; once baked, it can subsequently be toasted. It is most commonly eaten with the hands, either by itself or as a carrier for other foods. Bread can be dipped into liquids such as gravy, olive oil, or soup; it can be topped with various sweet and savory spreads, or used to make sandwiches containing myriad varieties of meats, cheeses, vegetables, and condiments.
==Crust==
The bread crust is formed from surface dough during the cooking process. It is hardened and browned through the Maillard reaction using the sugars and amino acids and the intense heat at the bread surface. The nature of a bread's crust differs depending on the type of bread and the way it is baked. Commercial bread is baked using jets that direct steam toward the bread to help produce a desirable crust.
The crust of most breads is less soft, and more complexly and intensely flavored, than the rest, and judgments vary among individuals and cultures as to whether it is therefore the less palatable or the more flavorful part of a particular style of bread. Some manufacturers, including Sara Lee, market traditional and crustless breads.
The first and last slices of a loaf (or a slice with a high ratio of crust-area to volume compared to others of the same loaf) are sometimes referred to as the heel or the crust of the loaf.
Old wives tales suggest that eating the bread crust makes a person's hair curlier. Additionally, the crust is rumored to be healthier than the rest. Some studies have shown that this is true as the crust has more dietary fiber and antioxidants, notably pronyl-lysine.