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On Dough And Bread

Reading notes during the Microresidency of Bridget Currie and Chloe Langford

From: On Food and Cooking

Food words: Dough, Bread, Flour

Dough comes from an Indo-European root that meant “to form, to build” and that also gave us the words figure, fiction and paradise (a walled garden). This derivation suggest the importance to early people's of dough's malleability, its clay-like capacity to be shaped by the human hand. Cooks have long used both clay and dough to make containers for cooking other foods, especially birds, meat and fish.

The word bread comes from a Germanic root, and originally meant a piece or a bit of a loaf, with loaf meaning the leavened baked substance itself. Over time, loaf came to mean the intact baked mass, and bread took over the loaf's original meaning. Otherwise we would now ask for a bread of loaf.

(…) the English word “flour” arose in the medieval times from “flower”, meaning the best part of the ground grain: that is, the portion left after screening out the large particles of germ and bran. To a medieval Englishmen, “whole wheat flour” would have neen a contradiction in terms.

Bread is nothing like the original grain, loose, hard, chalky and bland! Simply grinding grains, wetting the particles with water, and dropping the paste on a hot surface, creates a flavourful, puffy mass, crisp outside and moist within.

The two prehistoric 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 into a 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 gasses: and such a paste made a softer, lighter, more flavourful bread, especially when cooked from all sides at once in an enclosed oven.

Flatbreads were a common feature of late Stone Age life in parts of the world where grains were the chief food in the diet (…). Such breads were probably first cooked alongside an open fire, then on a griddle stone, and some of them much later in a beehive-shaped ovens, which were open at the top and contained both coals and bread; pieces of dough were slapped onto the inside wall.

Bread wheat, the unique species that 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 doughs arose spontaneously, since yeast spores are ubiquitous in the air on the 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 was already growing, but they've also valued less sour starters, especially the frothy residue from brewing beer.

In England around 1800 most bread was still baked in domestic or communal village ovens. But as the Industrial Revolution spread and more of the population moved to crowded city quarters, the bakeries took over an ever increasing share of bread production, and some of them adulterated their flour with whiteners (alum) and fillers (chalk, ground animal bones).

A new method of leavening made its first appearance in the first American cookbook, Amelia Simmons's 1796 American Cookery. Four recipes, two for cookies and two for gingerbread, call for the use of “pearlash”, a refined version of potash, which was made by soaking the ash when plant materials are burned, draining off the liquid and drying it down to concentrate the substances dissolved in it. Pearlash is mostly alkaline potassium carbonate, which reacts with acid ingredients in doughs to generate carbon dioxide gas. It was the precursor of baking soda and baking powders, which arrived between 1830 and 1850. These chemical ingredients made it possible to leaven instantly mixtures that living, slow-growing yeasts couldn't very well: such things as fluid cake batters and sweet cookie doughs. Purified commercial yeast cultures for loaf breads, more predictable and less acidic than brewer's yeast, became available from specialist manufacturers around the turn of the 20th century.

Wheat flour is strange and wonderful stuff! Mix pretty much any other powdery ingredient with water and we get a simple, inert past. But mix some flour with about half its weight in water, and the combination seems to come alive. At first it forms a cohesive mass that changes its shape reluctantly. With time and kneading, reluctance gives way to liveliness, a bouncy responsiveness to pressure that persists even after the kneader lets go.

The various textures of baked goods and pastas are created by the structures of their doughs and batters. Those structures are composed of three basic elements: water, the flour's gluten proteins, and its starch granules.

The structure of a dough or batter is temporary. When it is cooked, the starch granules absorb water, swell and create a permanent solid structure from the original, semisolid or liquid one. In the case of breads and cakes, that solid structure is a sponge-like network of starch and protein filled with millions of tiny air pockets. Bakers use the term crumb for this network, which constitutes the bulk of the bread or cake. The outer surface, which usually has a dryer, denser texture, is the crust.

Chew on a small piece of dough, and it becomes more compact, but persists as a gum-like, elastic mass, the residue that the Chinese named “the muscle of flour” and that we call gluten. It consists mainly of protein, and includes what may well be the largest protein molecules to be found in the natural world. (…) Gluten is a complex mixture of certain wheat proteins that can't dissolve in water, but do form associations with water molecules and each other. When the proteins are dry, they're immobile and inert. When wetted with water, they can change their shape, move relative to each other, and form and break bonds with each other. (…) Glutenin chains thus link us with each other end-to-end to form super-chains a few hundred glutenins long, and coiled stretches along their lengths readily form many temporary bonds with similar stretches along neighbouring gluten proteins. The result is an extensive interconnected network of coiled proteins, the gluten. The gluten of the bread wheats is both plastic and elastic; that is, it will change its shape under pressure, yet it resists the pressure and moves back toward its original shape when the pressure is removed. Thanks to this combination of properties, wheat though can expand to incorporate the carbon dioxide gas produced by yeast, and yet resists enough that its bubble walls won't thin to the breaking point.

Kneading unfolds and aligns the protein molecules, but there are still loops and kinks along their lengths. Stretching the dough straightens out these loops and kinks, but when the pressure is relieved, the molecules tend to revert to their original kinkiness. (…) The stretched dough creeps back toward its original shape.

Another important characteristic of wheat flour doughs is that their elasticity relaxes over time. An elastic dough that never relaxed could never be formed into the many shapes of raised doughs and pastas. (…) because the bonds are weak the physical tenson of the taut ball shape slowly breaks some of them, and the dough structure gradually relaxes into a flatter, more malleable mass.

There are a number of ingredients and techniques by which the baker controls the gluten strength and consistency of doughs and batters. They include (overview table on pp 524):

  • the kind of flour used
  • the presence of oxidising substances
  • the water content
  • stirring and kneading
  • salt (strengthens gluten network)
  • sugar (limits gluten development0
  • fats and oils (weaken gluten)
  • acidity in the dough (weakens the network)
  • eggs (stabilisation, coagulation)
  • milk, buttermilk (stabilisation, weakens gluten networks)

Starch granules serve several functions in doughs and batters. Together with the water they hold on their surfaces, they make up more than half the volume of the dough, interpenetrate the gluten network and break it up, and so tenderise it. (…) During the baking of bread and cakes, the starch granules absorb water, swell and set to form the rigid bulk of the walls that surround the bubbles of carbon dioxide. At the same time, their swollen rigidity stops the expansion of the bubbles and so forces the water vapor inside to pop the bubbles and escape, turning the foam of separate bubbles into a continuous spongy network of connected holes. If this didn't happen, then at the end of baking the cooling water vapor would contract and cause the bread or cake to collapse.

Gas bubbles are what makes leavened doughs and batters light and tender. Breads and cakes are aerated to the point that as much as 80% of their volume is empty space.

Bakers use yeasts or chemical leavenings to fill their products with gas bubbles. However, these ingredients don't create new bubbles: their carbon dioxide is released into the water phase of the dough or batter, and diffuses into and enlarges whatever tiny bubbles are already there. These primordial bubbles are air bubbles and are created when the baker first kneads a dough, or creams butter and sugar, or whips eggs. The initial aeration of doughs and batters thus strongly influences the final texture of baked goods. The more bubbles produced during the preparation of a dough or batter, the finer and tenderer the result.

Since the early 19th century, the term shortening has been used to mean fats or oils that “shorten” a dough, or weaken its structure and thus make the final product more tender or flaky. This role is most evident in pie crusts an puff pastry, where layers of solid fat separate thin layers of dough from each other so that they cook into separate layers of pastry.

Since the flour's normal endowment of sugars is enough to feed yeast cells for only a short period of time, flour manufacturers have long supplemented the ground wheat flour with malted wheat or barley: grains that have been allowed to sprout and develop the enzymes that break down starch to sugars (…) manufacturers are increasingly replacing them with enzymes extracted and purified from microscopic molds (“fungal amylase”).

From Wild Fermentation

In western culture, bread is synonymous with sustenance.

Beers can be used to start breads and breads can be used to start beers. They are made from the same ingredients, just with different processes and in different proportions. In both, yeast does the same thing; the primary thing yeast knows how to do: it consumes carbohydrates and transforms them into alcohol and carbon dioxide.

The yeasts found in nature are never pure. They travel in motley company. They are always found with other microorganisms. They embody biodiversity. They have unique flavours. And they are everywhere.

Pure yeasts need to act quickly, before any wild microorganisms have a chance to establish themselves. Wild fermentation is slower. The dough is given a chance to really ferment, breaking down hard-to-digest gluten into more easily absorbed nutrients, and adding B-vitamins. The yeasts are accompanied by Lactobacilli and other bacteria which produce acids and contribute complex sour flavours.

Many bakers I have known feel that breadmaking is a spiritual exercise that connects them to life forces. I quite agree: like any ferment, bread requires the harnessing and gentle cultivation of life forces. Bread also requires the full-body involvement of kneading. Kneading develops gluten, the rubbery component of wheat (…) , which enables the dough to trap bubbles of gas released by the yeast as it reproduces, thus yielding a light and airy loaf of bread.

Sourdough starter: page 95

Recycled Grain bread (using cooked rice, couscous, etc): page 96

- From Wild Fermentation by Sandor E. Katz

From: The Penguin Companion to Food

If the original Egyptian leaven bread was a combination of spontaneous lactic fermentation of flour and water with assistance perhaps from soured milk and further reinforcement from the spores of the wild, airborne yeast, brewers yeast induced and alcoholic fermentation, and was more predictable. The breads of some societies have relied mainly on lactic fermentation - which is the base of the whole family of sourdoughs - while others, especially in the Brittish isles, have long depended on straight alcoholic fermentations using brewers' yeast.

The first breads would have been cooked on flat stones heated directly in the fire. The bakestone remained the preferred method of cooking flat or unleavened breads in many cultures, from Mexico to Scotland, and is still in use. However, a natural step to take was to cover the bakestone with an inverted pot to contain the heat, and then to turn this makeshift arrangement into a domed, igloo-shaped or beehive oven. A free-standing structure of this sort, with its own source of heat, merely replicates on a larger scale the principle of the stone and pot. Early examples have been found in Mesopotamia, Egypt and the Balkans.

The beehive oven is heated by burning a fire on its floor. When the fire has heated the structure, it is raked out and the risen dough put in its place. The doorway is sealed and the bread cooks in a falling heat radiating from every surface, the oven space capturing and recycling any moisture that evaporates from the loaves.

During the 19th century, there were many experiments in conveying heat, just as other materials than brick, clay or stone, particulary steel were tried for the oven's construction. (…) The fullest expression of this is the travelling oven, where the goods to be baked moved through a heated space, going in cold and emerging fully baked.

Although ovens can be built any size, there are advantages of time and function in having them fairly large. The same can be said of mills. Hence bread-baking has often been a communal activity to avoid duplication of expensive resources. Grain is ground at the village mill, often in Europe in the hands of the political master; dough is baked in a communal oven, owned either by the lord or the community, or in the hands of a tradesman who gains his living therefrom.

In India leavening is often provided by palm yeast, obtain by the spontaneous fermentation of palm sap as it turns into toddy.

The Chinese were ignorant of the bread oven; so their bread, like that of the Newari people of Nepal was made by steaming, or the flour was converted into some form of flat pasta.

- From The Penguin Companion to Food by Alan Davidson

From various online sources

dough_and_bread.txt · Last modified: 2017/10/15 13:24 by nik