Chemistry of Cooking

The Evolution of Bread

Bread is a standard staple of our daily food choices.  Children and adults alike recognize the smell of freshly baked bread and understand its function in our diets and find it a satisfying, everyday, familiar food. Bread has evolved because of all the elements that go into its making: the grains, the machines for milling them, the microbes and chemicals that leaven the dough, the ovens that bake the loaves, and the people who make and eat it.  The word dough comes from an Indo-European root that meant “to form, to build,” suggesting the importance of dough’s malleability, its clay-like capacity to be shaped by human hands. The word bread comes from a Germanic root and originally meant a piece or bit of a loaf, a leavened, baked substance.  Over time, loaf came to mean intact baked mass and bread took over loaf’s original meaning.²

Development of Agriculture and Domestication of Grains

Before 10,000 years ago, man lived a nomadic life style as a hunter-gatherer relying on the hunting of wild animals and collecting wild plants for his food. Then, the Neolithic revolution took place where the hunter-gatherer way of life was replaced by an agrarian lifestyle. This was a crucial turning point in human history and had a profound effect on life thereafter. The Neolithic revolution spread through the Middle East and encompasses a region extending from Jordan, Israel, Lebanon, and Syria through southeast Turkey and along the Tigris and Euphrates rivers through Iraq and western Iran. This “cradle of agriculture” was the center of domestication of einkorn and emmer wheat, which were staple crops of early civilization and close relatives of modern day wheat. These cereals were domesticated alongside other important crops including barley, pea, lentil and chickpea, as well as animals such as sheep, goats, cattle and pigs, and they led the way for an agricultural revolution.

This agricultural revolution changed our species and our planet. As groups of hunter-gatherers began domesticating plants and animals, they quit the nomadic life, building villages and towns that endured for thousands of years.  A stable food supply enabled population to explode, and small groups turned into territories sprawling across hundreds of miles.

Agriculture originated in a few small hubs around the world, but probably first in the Fertile Crescent, the region that includes parts of modern-day Iraq, Syria, Lebanon, Israel and Jordan. The evidence for full-blown agriculture there — crops, livestock, tools for food preparation, and villages — dates back about 11,000 years.³

The early discoveries laid the foundation for the transformation of grains into breads and noodles, pastries and cakes.  The first was that in addition to being cooked in porridge, pastes of crushed grain and water could also be turned into an interesting solid by cooking them on hot embers or stones: the result was flatbread.  The second was that a paste set aside for a few days would ferment and become inflated with gases; and such a paste made a softer, lighter, more flavorful bread, especially when cooked from all sides at once in an enclosed oven.

Flatbreads were a common feature of the late Stone Age in parts of the world where grains were the chief food in the diet.  Some versions of these breads still exist and include Middle Eastern lavash, Greek Pita, Indian roti and chapati, all made mainly from wheat but also other grains, and the Latin American tortilla and North American johnnycake, both made from maize.  These breads were likely first cooked alongside an open fire, then on a griddle stone and some of them much later in beehive-shaped ovens.

Bread wheat, the unique species can make large, light loaves, had evolved by 8000 BCE, but the earliest archaeological evidence for leavened breads comes from Egyptian remains of around 4000 BCE.  The first raised dough arose spontaneously, since yeast spores are ubiquitous in the air and on grain surfaces, and they readily infect a moist, nutritious grain paste.  Bread makers throughout history have harnessed this natural process by leavening new dough with a leftover piece in which yeast is already growing. Grinding equipment progressed from the mortar and pestle to two flat stones and then around 800 BCE in Mesopotamia, to stones that could rotate continuously, by use of animal, wind and water power.

Leavened breads arrived fairly late around the northern rim of the Mediterranean.  Bread wheat was not grown in Greece until around 400 BCE.  It is documented that Greeks enjoyed breads and cakes flavored with honey, anise, sesame and fruits and that they made both whole grain and partly refined breads.  At least from the Greeks on, whiteness in bread was a mark of purity. By the early Roman times, wheat bread was a central feature of life and durum wheat and other bread wheats were imported from northern Africa and other parts of the empire to satisfy the public demand.

During the European Middle Ages, bakers were specialists, producing either common brown or luxurious white bread.  In the 17^th century, improvements in milling led to wide availability of white bread.  In northern areas, rye, barley and oats were more common than wheat and were made into coarse breads.  One use of these breads was as a “trencher,” a dense, dry, days-old thick slice that served as a plate at medieval meals and was either eaten or given away to the poor. Pastry was often use as a combination cooking and storage container, a protective and edible wrapping for mainly meat dishes.

During the late medieval period and into the Renaissance, there was notable progress in the production of enriched breads.  Domestic recipes for bread begin to appear in cookbooks for the middle class and already look similar to our current day versions. Eighteenth century English and American cookbooks contain dozens of recipes for breads, cakes and cookies.  In England in the 1800’s, most bread was still baked in domestic or village ovens.  As the Industrial Revolution spread and more people moved to the cities, bakeries took over an increasing share of bread production and some of them adulterated the flour with whiteners, like alum, and fillers, such as chalk and ground animal bones. 

Two trends developed in the 20^th century across North America and Europe.  One was the decline in the per capita consumption of plain bread.  People could afford to eat more meat and high-sugar, high-fat cakes and pastries in the place of regular bread products.  The second trend was the industrialization of bread-making.  Very little bread is made at home now; most bread is made in large central factories and some still in small local bakeries.  Mechanical aids to bread making, such as powered mixers, began to appear around 1900 and by the 1960’s; largely automated factories began to produce bread in a fraction of the time.  These manufacturing systems replaced the biological dough development, which includes the gradual, hours-long leavening and gluten strengthening of the dough by yeast with almost instantaneous, mechanical and chemical dough development. They are formulated to remain soft and edible for a week or more in plastic bags.

During the 1980’s, Europeans and Americans began to eat significantly more bread than they had just the decade before.  Traditional breadmaking was experiencing a revival and small bakeries began to produce bread using less refined grains and grain mixtures, build flavor with long, slow fermentation and baking in small batches.  A second reason for an increase in bread consumption was the invention of the home bread machine.  Home cooks were able to merely put all the ingredients in a single chamber, close the lid, and fill the house with the aroma of fresh-baked bread.  Although these two trends account for only a fraction of the production of bread, they do demonstrate that people still enjoy the flavors and textures of freshly made traditional breads.  Industrial manufacturers have responded to this revival by making bread products with taste and texture, not just minimum cost and shelf life, in mind.⁴