Yeast Doughs (Fermented Goods)

1.Role of Ingredients

Each ingredient used in bread making is employed for the specific characteristics it has and / or the result it has on the finished product. If there affects are understood, the ingredients may be selected with the assurance that the products produced will be good.

FLOUR: Flour is the primary structure builder in most cakes. The gluten formed during mixed coagulates during baking and assists in supporting the heave weight of sugar and shortening. Cake flour used in baking is made from soft wheats. Flour milled for bread baking will be made from hard wheat. Cake flour should have a low protein content (7 to 9 cent.). Cake flour should be properly bleached, because bleaching helps to carry more sugar and shortening as well as water during mixed. Cake flour should also have a P.H. of around 5.2 which is slightly acid. This acidity helps to mellow or soften the glutted.

SUGER: Sugar is used in cake as a sweetener. Sugar is considered a tenderized because of its tenderizing effect resulting from the softening action on flour proteins. Sugar lowers the carmelization point of the batter allowing the cake crust to color at lower temperature. Sugar helps to retain moisture left in the baked cake after baking thereby keeping the cake moist and edible for several days.

SALT:- Salt is used primarily for taste and to tone down the sweetness.

SHORTENING :- Shortening incorporates air the cake better during mixed . This air helps to obtain volume in the baked cake. It also tenderizes the cake. In making high ratio cake, an emulsified shortening must be used to from an emulsion .Reqlar shortening is not capable of forming an emulsion when large amount of sugar and liquid are used. If not enough liquid is used to dissolve the sugar, the cake will collapse in the center.

EGGS: Eggs furnish structure, moisture flavor, color and food value to the cake. Their most valuable contribution is structure. The proteins in the eggs coagulates during baking and assists the flour as a structure builder. Eggs is the only ingredient that can be used to regulate the toughening action in a cake. If weak flour is used, the eggs can be increased. If the percentage of shortening (a tenderized) called for in the formula is increased, the eggs must be increased also . It is important to know the percentages of fat, moisture , and protein of eggs when balancing cake formula.

MILK SOLIDS:
Milk solids have a binding effect on the protein of the flour, thereby increasing the toughness in a cake . A portion of the total solids in milk contain lactose sugar , which caramelized at a low temperature (270 to 275 deg. F). It is used to control crust color. It, along with the proteins in milk, adds food value and flavor to the cake helps to retain moisture in the cake. If liquid milk is used in lew of dry milk powder , it will be necessary to know the liquid content of the milk in order to make adjustments to the formula so the formula can be properly balanced.

LEAVENING:-
Cake are leavened mainly in three ways. Incorporation of air during mixing, chemically and vapor pressure created in the oven. The manner of leavening depends upon the type of cake being made in regard richness formula, consistency of batter and baking temperature. Cakes low in water and high in enriching ingredients get a large amount of leavening during mixing and require less chemical leaveners then cakes made from lean formulas high in liquids. In addition to leavening the cake, chemical leaveners control the eating qualities of the cake. Excess soda for example results in an undesirable “soapy taste”. Baking soda is necessary to produce the rice red color in devil food cake. However, one most be careful not to use too much soda in the formula. To produce a chocolate cake having a brown crumb color rater then a red crumb color, baking soda must be left out. Some types of cakes require no chemical leavening. Examples are the true pound cake and the basic sponge cake. These two cakes are leavened entirely by physical means such as air incorporated in the batter during mixing and vapor pressure created during baking. This is the reason why these types of cake require a longer mixing period and precise control of temperature of the batter during mixing.

2 Types of Dough (Rich/ Lean)

1. Rich Dough

There is no extra dividing line between rich and lean dough but, in general, rich dough contain higher proportions of fat, sugar, sometimes, eggs.

Nonsweet breads and rolls, including rich dinner rolls and briche. These have a high fat content but low enough sugar that they can be served as dinner breads. Brioche dough is especially rich, made with a high proportion of butter and eggs.

Sweet rolls, includes coffee cake and many breakfast and tea rolls. These have high fat and sugar and, often, eggs. They are usually made with a sweet filling or topping.

2. Lean Dough

A lean dough is one that is low in fat and sugar.

Hard- crusted breads and rolls, including French and italin breads, Kaiser rolls and other hard rolls, and pizza. These are the leanest of all bread products.

Other white breads and dinner rolls. These have a higher fat and sugar content and, sometimes, also contain eggs and milk solids. Because they are slightly richer, they generally have soft crusts.

Whole-grain breads. Whole wheat and rye breads are the most common. Many varieties of rye bread are produced with light or dark flours or with pumpernickel flour and with various flavourings, especially molasses and caraway seeds.

3.Method of Preparations

Bread Manufacture

The process of manufacture of bread starts with mixing and formation. Mixing and fermentation of dough is carried out by two methods:

· Straight Dough method.

· Sponge Dough method.

Straight Dough Method

It is more common in India which consist of in mixing together. The quality of bread depends upon the thorough mixing of all the components and proper kneading. This is carried out mechanically in large bakeries and manually in small bakeries. The kneading machine consists of a slow rotating or stationary vessels in which the flour is worked by means of a number of moving arms. The ferment is added during kneading and salt is added after preliminary rising of the dought.

Sponge Dough Method (Semi-Automatic)

Mixing and Fermentation

Sifted flour is conveyed automatically to the weighing hopper (scale) above the mixer, about 60-80% of the flour required for a batch is weighed into the mixing bowl. Yeast, the enrichment ingredient suspended in water, and the yeast food are added on top of the flour, the proper amount of water is metered into the bowl, and these ingredients are then mixed into a sponge. Mixing at this point serves to produce a homogeneous mass but not necessarily to produce full development of the wheat gluten. If enzymes are used as flour supplements, they may be added to the sponge. The sponge is then dumped from the mixer into greased troughs which are wheeled or conveyed by monorail to the fermentation room where the temperature is maintained at about 27°C and the rh. at 75-80%. Sponge fermentation time is variable but ranges from 3.5 to 5 h. As die fermentation proceeds there is a dramatic increase in the volume of die sponge; the sponge usually rises until it becomes so stretched that it falls spontaneously After the sponge is properly fermented it is returned to die mixer where the remaining flour and water, non fat dry milk, sugar, salt, shortening, and odier minor ingredients are added and the dough is mixed.

At this stage, the baker desires not only to produce a homogeneous mixture, but also to develop the gluten by repeated stretching. This improves grain and texture, too litde or too much mixing harms bread quality. Mixers are jacketed so that the temperature of the sponges and doughs can be controlled either by circulating refrigerant or brine in the jacket, or by using direct-expansion coils. When the dough is removed from die mixer its temperature is about 27°C. The properly mixed dough is again ejected into a trough where it is permitted a rest period (floor time) of 15-45 min. before going to the make up department.

Make up

After die necessary floor time the dough is transferred to the hopper of die divider. This is generally done by hoisting and tilting the trough so that die dough slides out a trapdoor at die end of die trough. The divider consists of cylinders of adjustable size and of pistons which operate in die cylinders. Movement of a piston draws dough into a cylinder. The cylinder door closes, cutting off the piece of dough, which is then forced out of the chamber onto a travelling belt. The weight of the dough pieces is checked frequendy. If the dough pieces are over or underweight die size of the cylinders is adjusted.

A moving belt carries die dough pieces to die rounder where they are converted from rough, ragged pieces to smooth, spherical shapes. The rounder consists of a rotating cone and a pressure board. The dough pieces are rolled and compressed as they travel up die pressure board. The rounded dough is then transferred mechanically to an overhead proofer, which is a large enclosed chamber through which the dough pieces are carried on trays suspended on a chain drive. During die trip through the overhead proofer which takes about 15 min., the gluten, which has been tightened by die previous manipulation, relaxes, and the dough pieces become pliable.

Each dough piece is conveyed from die overhead proofer to the molder, which first sheet the dough by passing it dirough roller (generally Teflon coated). Then the molder curls the sheet into a cylinder which is dropped automatically into the pan in which the bread is baked. Four to six pans are usually joined together in straps by means of cross pieces; this facilitates proper aligning through the next stages in die baking process.

Proofing and Baking

The panned dough must be permitted to rise (proof) in die pan to assure the volume required of finished bread; during this period the dough expands to about six times its original volume. Proofing can be done in continuous proofers where the pans are conveyed through a temperature and humidity-controlled cabinet kept at about 35-43°C and 85-95% rh. and then to the oven. It can also be done by loading the pans into racks, which are wheeled or conveyed by monorail into a proof box. Proofing requires about 1 h. From the proof box the dough goes to the oven. If a continuous proofer is used, the transfer to the oven is entirely mechanical. If proofing is done on racks the straps of pans are transferred to die oven by hand. Most ovens are traveling tunnel or lap ovens in which the pans of proofed dough are loaded at one end and the baked loaves come out of the other. The oven may consist of several chambers at different temperatures. Currendy, one-pound (0.45 kg.) loaves of bread are baked for about 17-23 min. at an average temperature of about 215-225°C.

Cooling, Slicing and Wrapping

The baked bread is depanned automatically and conveyed by belts drought the bread cooler to lower the temperature to 40.5°C. From the bread cooler, the bread goes to the slicer and wrapper. It is sliced by rapidly moving, razor-sharp bands and may be wrapped in waxed paper or transparent film or bagged in plastic bags. The packages are heat-sealed, twist tied, or plastic clipped, and may bear an end seal.

Rolls, buns, and sweet yeast-raised products are made in much the same way as bread except that special machines are required to produce the unique shapes and to fill and ice sweet rolls and coffee cakes.

5.Bread Staling

Once out of the oven , bread beings to stale. The manifestations of staling are the toughness or leathery nature of the curst along with the development of the dry, harsh texture of the crumb and a stale flavour. The basic cause of staling is the transformation of starch from one form to another at temperatures below 550C . The starch becomes more crystalline below this temperature below 550C .

The starch becomes more crystalline below this temperature. The change in the from of starch results in the binding of less water leading to rapid hardening, and to the shrinkage of the starch granules away from the gluten skeleton with which they are associated, with the consequent development of crumbliness.

These changes occur in bread even though it is sealed in a moisture/vapour-tight wrap. It is believed the changes in starch during staling are more due to the arnylo-pectin portion of starch than the amylose portion. Amylose is insolubiiized irreversibly by retrogradation during baking and hence cannot influence the staling that occurs subsequently.

Microbiological spoilage:

Breads undergo microbiological spoilage due to the growth of molds and undesirable bacteria. At the high temperature of baking, mold spores are destroyed. However, the molds that deposit on bread during the handling process develop during storage and affect the quality of bread. Mold infection can be prevented by the addition of sodium or calcium propionate.

Some bacteria which are members of the Bacillus mesentericus group, if present in dough, are not destroyed in the interior of bread during baking and develop in bread later bringing about a change in colour, texture and disintegration of the crust which is known as "rope". Propionates also eliminate ropiness in bread.

Simple Yeast Raised Breads

Yeast

• Provides the basic culture for bread to ferment

• Develops flavor of bread

• Helps in releasing carbon-di-oxide that gives porosity to the crumb.

8.4 Steps in Bread Making

There are basically 12 steps in Bread Making

Step 1: Scaling

All ingredients are measured. We would like to recommend two things for this step:

Measure all wet and dry ingredients by weight.
Use a formula that is expressed in "baker's math" or "baker's percentages."

This step concludes when all ingredients are accurately measured and lined up in order of use, as well as all tools and equipment are ready for the second step in the bread-making process.

Step 2: Mixing

Ingredients are combined into a smooth, uniform dough; the yeast and other ingredients are evenly distributed through the dough, the gluten is developed, and fermentation is initiated.

Step 3: Bulk or Primary Fermentation

The dough is allowed to ferment. Fermentation is the process by which the yeast acts on the sugar and starches and produces carbon dioxide and alcohol.

Step 4: Folding

The purpose of this step is to degas the dough, and we do that for four reasons: to expel some of the carbon dioxide, and avoid by that chocking the yeast; to allow the gluten to relax a bit; equalize the temperature of the dough; and to redistribute the nutrients necessary for the yeast’s continued growth.

Step 5: Dividing or Scaling

The dough is divided or scaled into the desired individual portions.

Step 6: Pre-shaping or Rounding

The portioned dough is loosely shaped into smooth, round balls. This organizes the dough into consistent pieces and makes the final shaping easier and more efficient. It also stretches the gluten on the outside of the dough and forms a skin that helps it retain the gases produced by the yeast.

Step 7: Resting

The benching or resting lasts approximately 20 to 30 minutes and relaxes the gluten, making the final shaping of the dough easier.

Step 8: Shaping and Panning

The dough is formed into its final shape and placed in the pan or mold that it will be baked in. Hearth breads that will be baked directly on the oven deck are placed in bannetons or between the folds of baker’s linen.

Step 9: Proofing or Final Fermentation

The dough goes through one final fermentation. The dough should be placed in a temperature and humidity controlled environment to allow the bread to rise to the desired volume before baking. Optimum rise for this stage is 80 to 85 percent of the dough’s overall volume.

Step 10: Baking

The dough is baked. The dough is often scored with a sharp knife prior to baking. This allows the bread to expand without bursting.