Why Does Bread Have Holes in It?
The holes in a piece of bread are made by bubbles of gas. In bread making, flour and water are mixed to form dough. Then a small amount of yeast is added to the mixture. Yeast is a type of fungus which grows very quickly when it is warm and damp. While growing, it gives of a gas which bubbles up through the dough, making it expand. It is yeast which gives bread its particular flavor and appetizing smell.
No one knows when yeast was first used to make bread, but it must have been many thousands of years ago. According to one story, the idea was the result of an accident. Some yeast is said to have got into the dough by chance and made it rise. Because this loaf was twice as big as normal, people thought it must be magic. But as the bread tasted better than the usual flat, heavy loaves, they soon used yeast to make all their bread.
Cakes also have holes in them made by bubbles of gas. But these are made by a different substance which leaves practically no flavor. This substance is baking powder, which is a mixture of tartaric acid and bicarbonate of soda. When these two chemicals are mixed together, wetted and heated, they react to produce carbon dioxide. This gas bubbles through the cake mixture to make it rise while being baked.
Bread is one of the oldest prepared foods. Evidence from 30,000 years ago in Europe revealed starch residue on rocks used for pounding plants. It is possible that during this time, starch extract from the roots of plants, such as cattails and ferns, was spread on a flat rock, placed over a fire and cooked into a primitive form of flatbread. Around 10,000 BC, with the dawn of the Neolithic age and the spread of agriculture, grains became the mainstay of making bread. Yeast spores are ubiquitous, including on the surface of cereal grains, so any dough left to rest leavens naturally.
There were multiple sources of leavening available for early bread. Airborne yeasts could be harnessed by leaving uncooked dough exposed to air for some time before cooking. Pliny the Elder reported that the Gauls and Iberians used the foam skimmed from beer to produce “a lighter kind of bread than other peoples.” Parts of the ancient world that drank wine instead of beer used a paste composed of grape juice and flour that was allowed to begin fermenting, or wheat bran steeped in wine, as a source for yeast. The most common source of leavening was to retain a piece of dough from the previous day to use as a form of sourdough starter, as Pliny also reported.
In 1961 the Chorleywood bread process was developed, which used the intense mechanical working of dough to dramatically reduce the fermentation period and the time taken to produce a loaf. The process, whose high-energy mixing allows for the use of lower protein grain, is now widely used around the world in large factories. As a result, bread can be produced very quickly and at low costs to the manufacturer and the consumer. However, there has been some criticism of the effect on nutritional value.
Bread is the staple food of the Middle East, North Africa, Europe, and in European-derived cultures such as those in the Americas, Australia, and Southern Africa, in contrast to East Asia where rice is the staple. Bread is usually made from wheat-flour dough that is cultured with yeast, allowed to rise, and finally baked in an oven. The addition of yeast to the bread explains the air pockets commonly found in bread. Owing to its high levels of gluten (which give the dough sponginess and elasticity), common or bread wheat is the most common grain used for the preparation of bread, which makes the largest single contribution to the world’s food supply of any food.
Bread is also made from the flour of other wheat species (including spelt, emmer, einkorn and kamut). Non-wheat cereals including rye, barley, maize (corn), oats, sorghum, millet and rice have been used to make bread, but, with the exception of rye, usually in combination with wheat flour as they have less gluten. Gluten-free breads have been created for people affected by gluten-related disorders such as celiac disease and non-celiac gluten sensitivity, who may benefit from a gluten-free diet.
Gluten-free bread is made with ground flours from a variety of materials such as almonds, rice, sorghum, corn, or legumes such as beans, but since these flours lack gluten they may not hold their shape as they rise and their crumb may be dense with little aeration. Additives such as xanthan gum, guar gum, hydroxypropyl methylcellulose (HPMC), corn starch, or eggs are used to compensate for the lack of gluten.
Bread has significance beyond mere nutrition in many cultures because of its history and contemporary importance. Bread is also significant in Christianity as one of the elements (alongside wine) of the Eucharist, and in other religions including Paganism.
In many cultures, bread is a metaphor for basic necessities and living conditions in general. For example, a “bread-winner” is a household’s main economic contributor and has little to do with actual bread-provision. This is also seen in the phrase “putting bread on the table”. The Roman poet Juvenal satirized superficial politicians and the public as caring only for “panem et circenses” (bread and circuses). In Russian 1917, the Bolsheviks promised “peace, land, and bread.” The term “breadbasket” denotes an agriculturally productive region. In Slavic cultures bread and salt is offered as a welcome to guests. In India, life’s basic necessities are often referred to as “roti, kapra aur makan” (bread, cloth, and house).
Words for bread, including “dough” and “bread” itself, are used in English-speaking countries as synonyms for money. A remarkable or revolutionary innovation may be called the best thing since “sliced bread”. The expression “to break bread with someone” means “to share a meal with someone”. The English word “lord” comes from the Anglo-Saxon hlāfweard, meaning “bread keeper.”