THE SCIENCE OF BAKERY (Written in 1897 - 111 years ago)
§ 472. The main materials for baking are flour and water; secondary - salt, butter, sugar and spices, and auxiliary (for raising the dough) yeast or sourdough. Of the four types of grain bread (wheat, rye, barley and oats), wheat and rye are preferred for baking; barley and oats are used only in those areas where rye and wheat do not grow. The reason for the preference of wheat and rye lies in the excellent qualities of their gluten: in wheat and rye gluten (especially in the first one), the most developed properties are necessary for preparing and raising dough, namely: viscosity, elasticity, the ability to bind water. In barley gluten, these properties are developed to a much lesser extent: barley gluten is not very viscous and therefore, when the dough is stirred, it is difficult to assemble into a whole mass, and barley dough, due to its weak elasticity, easily breaks through with gases during rising and therefore does not rise well; for these reasons, barley flour gives a dense and indigestible bread. Oats contain not only poorly suitable gluten, but also in too little quantity.
§ 473. The following processes are distinguished in baking: 1) preparation of dough, consisting of dissolving and kneading; 2) raising the dough; 3) felting and 4) baking.
To prepare the dough, take about 2 hours of water for 3 hours of flour. Excess water is harmful because it makes the dough runny, spreading, and therefore difficult to rise. With a lack of water, an imperfect conversion of starch into a paste occurs (later, during baking), as a result of which the bread responds with raw flour.
Yeast is used for baking beer, leaven, etc. For 100 pounds of flour, approximately 2 lb. yeast.
Leaven is a fermenting dough left over from the previous baking and slightly sour as a result of the sour fermentation that developed in it (§ 408). The leaven contains the enzyme of alcoholic fermentation and therefore can serve for raising the dough instead of yeast, but since it contains dark-colored (brown) products formed from the decomposition of gluten during sour fermentation, it is used only when baking rye bread. To preserve the leaven, it is dried or kept in the cold, or fresh flour is periodically added to it. £ 100 flour is taken when prepared dough 4 lb. sourdough. With daily baking, all the required amount is cut off at once; when baking every other day - half; after two days - a quarter, and little by little fresh flour is added to the required amount.
§ 474. To dissolve the dough, place the proper amount of flour (less against the calculated one), water and yeast or sourdough in a wooden trough or tub (sourdough) and mix thoroughly by hand or with a wooden paddle. The resulting liquid dough (solution for rye bread and dough for wheat) is allowed to rise somewhat. After that, they start mixing the dough, that is, mix the dough, adding it first with the rest of the flour. It is necessary to knead the dough as thoroughly as possible, because only with good kneading the yeast or sourdough is distributed evenly throughout the whole mass of the dough and it is raised in all parts equally. Hand kneading is extremely difficult, tedious and extremely untidy, even if you want to keep clean, since perspiration inevitably gets into the dough from the hands or feet (for example, when preparing pumpernickel, which is kneaded by the feet) of the worker.For a long time these reasons have prompted the offer of kneading machines adapted to both large and small bakeries; however, partly due to the imperfection of its structure, partly due to our attachment to old customs, kneading machines are very slowly coming into use and are so far found only in large bakeries.
§ 475. The kneaded dough is left to stand quietly in a warm room to allow alcoholic fermentation to develop; the resulting carbonic anhydride presses on the dough and, not being able to break through the elastic and viscous gluten, only inflates and stretches it, forming many voids inside the dough; the dough swells and becomes porous - it rises. If the yeast is evenly distributed in the dough, then it rises in all parts the same, the voids are of equal size and the bread is light, conveniently soaked in digestive juices and therefore digestible. If the yeast is unevenly distributed in the dough, then in places large voids are puffed up, in places the dough does not rise at all, it is poorly baked during subsequent baking and the finished bread responds with raw flour.
§ 476. The risen dough is rolled in flour, separating pieces of the required size and giving them the required shape. Skillful shaping of the bread is of great importance, because the shape of the bread affects the time it takes to bake it, namely: the less the surface of the bread in relation to its weight and the more the shape of the bread approaches the ball, the more time it takes to bake ... By increasing the length of the bread, but not changing its height and width at the same time, it is possible to achieve that large bread will be baked as quickly as small. Since during the subsequent baking the dough significantly decreases in weight due to the evaporation of water, a little more dough is taken to obtain a given weight amount of baked bread. Weight loss during baking varies; it depends mainly on the duration of baking and on the size of the bread and is the more, the smaller the bread, because in small bread more crust is formed. Since the weight loss during baking ranges from 12% to 20%, for large loaves, take for each pound of bread from 36 to 38 lots of dough.
§ 477. The formed dough is put into the oven. The simplest example of a baking oven is the Russian oven. It consists of a stone platform - the so-called. a hearth, covered with a more or less flat vault and serving, in succession, as a place for burning fuel and for planting bread; in front there is an inlet hole through which fuel and molded loaves are introduced into the oven; smoke from the burning fuel comes out through the same hole, which is then carried out by a chimney (made in the vault in front of the mouth) into the chimney.
When the oven is hot enough, which can be seen by the rapid browning of the flour thrown on the underside, the ash is scooped up and the formed loaves are planted in its place, and the mouth of the oven is closed to retain water vapor under the roof, necessary for the formation of gloss on the crust. The temperature is controlled by opening or closing the chimney damper, as well as the mouth of the oven, through which the progress of the baking is monitored from time to time. The dough, planted in the oven, begins to heat up gradually, first from the surface (by radiant heat from the arch and direct contact with the hearth), and then in the inner parts; carbon dioxide bubbles trapped in the dough expand from heating; the alcohol formed during fermentation turns into steam; as a result, increased pressure is detected inside the dough, and the dough rises, while increasing in volume almost twice. At a temperature of about 70 °, starch grains bind water, turning into a paste, as a result of which the wet dough becomes dry (like boiled potatoes) and, as the paste dries, it becomes so stable that its voids do not tighten even if some of the gases evaporate upon further heating ... Later, the starch is partially converted to dextrin and glucose (§452).As the temperature rises, water evaporates from the dough, mainly from the surface heated the most; as a result, the surface layer of the dough dries and hardens and forms a crust; the starch of the crust is converted into dextrin (§ 451), which dissolves in a small amount of water and covers the crust as if with a varnish layer. Little by little, the crust changes its color: first it turns yellow and then turns brown; at the same time, aromatic substances are formed in it. If the temperature continues to rise, charring occurs.
§ 478. Baked bread must be cooled gradually so that the crust does not lag behind the crumb, as they shrink unevenly when cooled. Therefore, the breads taken out of the oven are placed side by side, as close to each other as possible. Well-baked bread should be lightweight, have a tough, brittle, smooth crust and soft elastic crumb, show fine, frequent nostrils in the section, and be easily soaked in saliva. The crust, cracked in places, indicates that the oven heat did not increase gradually, the crust was formed prematurely and was broken by escaping bubbles of carbon dioxide gas or steam. This can be prevented by piercing the bread with something in several places before placing it in the oven. A dark colored crust indicates that the oven was too hot; in this case, it is worth covering the cooling bread with a napkin and thus holding back the water vapor coming out of it so that the crust becomes soaked and lighter, but at the same time softer. The weight ratio of crust to crumb is 1/4 - 1/6; the amount of water in it is from 15% (or less) to 20%. The crumb of rye bread contains approximately 48%, and wheat bread - 45% water.
§ 479. The yield (amount obtained) of bread from a given weight of flour is very different and depends on the type of flour, the amount of gluten and water in it, the size of the bread and the duration of baking: 100 hours of wheat flour gave, for example, 120-130 hours of bread (small value); 100 hours spelled -145 hours bread; 100 hours rye -131-145 hours and more. The excess weight of baked bread versus the weight of flour consumed is called baking. Pastry is water that is added to flour to turn it into bread. Possibly more heat is beneficial only for the bread maker, while the consumer only needs the least amount of heat that is absolutely necessary to turn flour into digestible bread; any surplus of hot bake delivers to the consumer only an appropriate amount of water, paid on an equal basis with bread.
§ 480. Bread should be stored in a cool and not too damp place. The most common spoilage of bread is its staleness, which, however, is not due to the evaporation of water, although its symptoms coincide with those of dryness. It is known that it is worth heating stale bread to 75 degrees so that it becomes soft again, on the other hand, fresh bread with 40% water should lie down for a week (during which it loses only 2% of water) to become completely stale. It is obvious that staleness is not dehydration, but what exactly it is is unknown. It has been noticed that bread made from coarse flour, cooked with sourdough and rich in gluten (such as rye), turns stale much more slowly.
§ 481. For our nutrition we need organic and mineral substances; between the first of them, there are substances containing nitrogen, for example, chicken egg white, meat, cottage cheese, etc., and substances that do not contain nitrogen, for example, starch, sugar and fat; nitrogenous organic matter is considered more nutritious than nitrogen-free; the ratio between the one and the other, necessary for proper nutrition, is taken 1: 5. In terms of chemical composition, cereal grains represent a happy combination of nitrogenous and nitrogen-free nutrients, approximately in the above quantitative ratio, namely 1: 6. This favorable ratio, however, does not pass into flour, because a significant part of nitrogenous substances, namely gluten, remains in bran, so that the ratio of nitrogenous substances to nitrogen-free (gluten to starch) in high-grade wheat flour is expressed in numbers 1: 8 and even to 8.5; in bran it is 1: 4. This apparent loss of gluten, the most nutritious component of the bread, was the reason that the currently used grinding methods, aiming to obtain as much white, starchy flour as possible, were considered unfounded; this was followed by a number of ways to use the whole grain for baking without prior removal of the bran. We will not describe these methods, since they did not receive distribution. In the following, we will find out the reason for this, and at the same time we will show in what position the question of the comparative nutritional value of white bread, which does not contain bran, and bran bread, currently stands.
§ 482. Although the nutritional value of bread is closely related to the amount of gluten in it, a large amount of gluten in bread does not always guarantee its nutritional value. The fact; that only that part of the gluten is digestible that is completely separated from the membranes and therefore does not contain indigestible fiber; gluten - associated with the membranes, is not digested at all. Direct experiments have shown that bread made from flour, free from bran, and therefore containing only free gluten, gives the body the greatest amount of it, and therefore is the most nutritious; Bread - baked from whole grain and, therefore, not at all separated from the bran, gives the body the least amount of gluten and therefore is the least nutritious.
§ 483. If, however, we compare the monetary value of feeding on starchy and branded bread varieties, that is, to determine how much it will cost for each of these varieties, which will bring into the body the same amount of digestible and therefore assimilable nitrogenous substances, sufficient for nutrition, then the opposite will turn out, namely: preference will have to be given to bread made from the most branded, and therefore the cheapest flour. Therefore, if it is only about proper nutrition, that is, about the introduction into the body of a sufficient amount of nutrients with the least possible burden on the stomach, then white wheat bread should be preferred; he will always be food of sufficient classes. In those cases when the money issue is, of necessity, in the foreground (when feeding the masses or poor classes), bran varieties will always be preferred. The established use of bran grain for food for the army, workers, our peasant class, etc., agrees with this.
It was 111 years ago - and the principle has practically not changed, everything is as it is today, with the same words and concepts. Wonderfully
