BASIC
COMMODITIES –NOTES
FATS/OILS/SHORTENINGS
Oils are liquid at normal temperatures, but solidify at lower temperatures. Those commonly used in cooking are peanut (groundnut/arachide) oil, coconut oil, mustard seed oil, sesame (teel) oil, olive oil and safflower oil.
Shortenings are fats that are used in the baking industry and in confectionery.
HYDROGENATION OF OILS
The conversion of oil into fat is known as hydrogenation. The process changes the physical properties of the oil. Hydrogenation consists of treating oil under pressure and at a suitable temperature with hydrogen, in the presence of a catalyst, usually nickle. Under these conditions, the unsaturated fatty acids present in the oil combine with the hydrogen. This chemical process brings about a physical change, the liquid oil changing into a solid fat. The unsaturated fatty acids are chiefly those of the oelic type and are converted into stearic acid which is solid. The varying consistencies available in fats is due to the process of hydrogenation being stopped at various stages.
SHORTENINGS
Fats can be used as shortenings or as a cooking medium. In confectionery, fats impart their characteristic flavor as well as shortening qualities. Their effect is to coat and break down the gluten strands, so that instead of being hard and tough to eat, foods containing shortening break off short and melt readily in the mouth.
FACTORS TO LOOK FOR IN SHORTENINGS:
1. Creaming Value: This effect the volume of the item eg: cakes
The amount of air incorporated during creaming
2. Shortening value: The shortness it gives to the end product. Shortness
is a quality essential in products such as biscuits & cookies.
3. Stability: Refers to keeping quality and shelf life.
4. Consistency: Hardness or Softness depending on the purpose.
hardness for puff pastry, softness for cakes.
5. Water absorption Will affect the emulsification value of the shortening.
power:
As shortening agents, fats add to the nutritional and satiety values of flour mixtures like doughs and batters. They also contribute to the taste and flavor. The type of fat and the way it is incorporated will affect the texture (eg: short crust pastry and flaky pastry). Baking must be done at correct temperatures. As the fat melts during baking, it must be absorbed by the flour. If the heat is insufficient, the melted fat will run out and result in a hard product. Fat which has been broken up into small particles during creaming will be more easily absorbed than fat left in large pieces.
Fat as a frying medium functions in three ways:
- it serves to transmit heat to the articles of food to be fried.
- it adds to the nutritive value (calories).
- It contributes to the flavor and taste and texture of the food.
Fat used as a frying medium must have
- a high smoke point
- low congealing point
- low moisture content
- high stability
- acceptable flavor which is neutral
RENDERING OF FAT:
Rendering of fat is the process of melting to extract fat from fatty tissues. A good supply of fat can be obtained in this way there are two methods to complete this process:
1. Cut the fat into small pieces, put them in a baking tray and heat in the oven till the fat has melted and only crisp brown pieces of tissue remains. Strain the fat through a clean cloth into a basin and store in the refrigerator.
2. Cut the fat into small pieces and cover with a little water. Boil, without the lid until the water has evaporated and the fat melts leaving behind only tissue. Strain and store as above.
In both cases, the temperature should not be too high as the fat will decompose.
CLARIFICATION OF FAT:
This method of cleaning the fat. Used fat is mixed with water and allowed to boil. It is then strained and allowed to cool. The fat solidifies on the surface. This cake of fat is lifted out and the bottom scraped off all impurities. The fat is then heated till it stops bubbling and the water particles have disappeared.
TYPES OF FATS AND OILS
FAT/OIL SOURCE PROPERTIES USES
Butter Cream Salted or unsalted, shallow frying
Difficult to handle when chilled, unsuitable for
Deep frying. Unique flavor, Good enriching qualities.
Margarine Groundnuts Not easy to spread. Economical for baking
Palm, coconut, Low cholesterol
Fish oils, Whey
Soft blend as above will spread even if
Margarine chilled excellent for cake & pastry making
Low fat Blended Low calorie content can be used for baking
Spreads & vegetable oils but not for pastry. Spreads when chilled
Cholesterol
Free Spreads
Lard Pork White solid fat, good for Short Crust
Pastry & Shallow frying.
Not suitable for creaming with sugar.
Economical
Suet Lamb or Hard white fat, good for Short crust, steamed
Beef puddings & stuffings
Corn Oil Corn Refined . All purpose especially deep frying
Sunflower/ Sunflower & Refined. All purpose cooking medium
Safflower oil Safflower seeds
Sesame/ Sesame seeds/
Gingelly oil (teel)
Olive Oil Olives Distinctive taste & flavor, Salad dressings
Cooking medium, but not deep frying
Soya bean Soya beans Distinctive All purpose cooking medium
Oil
Coconut Coconuts Strong aroma & flavor. Used a lot in Kerala
Oil and Coastal cuisine
Mustard Mustard Strong aroma & flavor Used in North Indian
Oil plant & Bengali cuisine and in pickles
Arachide Groundnuts Distinctive flavor. All purpose cooking
Oil medium
Pure Ghee Cream Rich flavor used extensively in Indian
Cooking and sweets
Solid Palm Neutral flavor Suitable for all types of cooking
Vegetable
Oil
In short, Fats & Oils can be classified as:
Animal Sources: Lard, Suet
Dairy Sources: Butter, Pure Ghee
Vegetable Sources: Refined oils
Margarine
BASIC COMMODITIES RAISING AGENTS
Raising agents are also known as leavening agents. Leavening is the production or incorporation of gases in a baked product to increase volume and to produce taste and texture as well as shape. These gases must be retained in the product until the structure is set enough by the coagulation of gluten and /or egg protein to hold its shape. Exact measurement of leavening agents is important, because small changes can produce major defects in baked products.
TYPES OF RAISING/LEAVENING AGENTS
Biological: Yeast
Chemical: Baking powder, Baking soda, Baking ammonia
Mechanical: Air, Steam
YEAST
Fermentation is the process by which yeast acts on carbohydrates and changes them into carbon dioxide and alcohol. This release of gas produces the leavening action in yeast products. The alcohol evaporates completely during and immediately after baking. The process of fermentation is brought about by an enzyme called zymase.
Yeast is a microscopic plant. As a living organism, it is sensitive to temperatures.
45°F (7°C) Inactive; storage temperature
60-70°F (15-20°C) Slow action
70-90°F (20-32°C) Best growth, proofing temperature for dough
Above 100°F (38°C) Reaction slows
140°F (60°C) Yeast is killed
Yeast will contribute to flavor in addition to leavening action. There are various market forms of yeast, which are available.
Dried Yeast: is a mixture of yeast and cornflour or cornmeal, which are pressed into cakes and dried. The yeast continues to live, but in an inactive state. When furnished with warmth and moisture, it begins to develop and multiply, but this process is slow. Dried yeast has to be soaked in lukewarm water and mixed with very soft dough for a preliminary period before the other ingredients are added.
Activated Dried Yeast: This develops more rapidly than dried yeast and is the type that is most commonly used these days. It can be added straight into the flour. It is also less perishable than compressed yeast (see below). The shelf life of both dry and activated dry yeast is longer when stored in the refrigerator.
Compressed Yeast: has This is a moist mixture of yeast plants and starch. The yeast remains active and will grow and multiply rapidly when added to dough. It has to be kept refrigerated and will keep well only for a few days. If held in the freezer, it retains its activity for a longer period.
CHEMICAL LEAVENERS
Chemical leaveners are those that release gases produced by chemical reactions.
Baking Soda: is the chemical sodium bicarbonate. If moisture and acid are present, soda releases carbon dioxide gas, which will leaven the product. Heat is not necessary for the reaction, although the gas will be released at a faster rate if the temperature is increased. For this reason, products leavened with soda must be baked immediately otherwise the gases will escape and the leavening power will be reduced. Acids that react with soda in a batter or dough would include honey, molasses, buttermilk, fruits, cocoa and chocolate. Sometimes, acids, such as cream of tartar are added to induce the production of carbon dioxide.
Baking Powder: is a mixture of baking soda and an acid such as cream of tartar and diluted with cornflour to give a product of the desired strength. The cornflour also serves to separate the acid and the base, thereby increasing the stability of the mixture. General proportions used are 1 to 2 tsps /500 GMS of the flour or foundation ingredients. Baking powders are more versatile since they do not depend on acids for their leavening power. Do not include more baking powder in a recipe, as it will create an undesirable flavor.
Baking Ammonia: is the chemical ammonium carbonate. It decomposes during baking to form carbon dioxide gas and ammonia gas. Only heat and moisture are required for it to work. No acid is required for reaction to take place. Baking ammonia releases gases very quickly and can only be used in small products like cookies or in products like choux pastry where rapid leavening is desired. Because it decomposes quickly, it leaves no residue, which could affect the flavor.
MECHANICAL AGENTS
Air: is incorporated in a batter primarily by two methods. This air expands during baking and will leaven the product.
1. Creaming – is the process of beating fat and sugar together. Besides breaking up the fat into minute particles, it also incorporates air into the mixture. It is an important technique in cake making and in cookie making as well. Some pound cakes and cookies are aerated entirely by this method.
2. Foaming – is the process of beating eggs, with or without sugar, to incorporate air. Foams made with whole eggs are used for sponge cakes, while meringues, angel food cakes and soufflés are aerated with only egg whites.
Steam: When water turns to steam, it expands to 1600 times its original volume. Because all baked products contain some moisture, steam is an important leavening agent. Bakery products such as eclairs and cream puffs rely on steam for aerating. If the starting temperature for the baking of these products is high steam will be produced and rapidly aerate the product.
BASIC COMMODITIES I FLOUR
Flour is one of the basic and foundation ingredients used in the kitchen, especially in the bakery.
WHITE WHEAT FLOUR (refined flour)
White wheat flour is milled from the kernels of wheat after the outer covering called bran and the germ is removed. Wheat flour contains 63 – 73% starch and 7 – 15 % protein. The rest is moisture, fat, sugar and minerals. Wheat flour is the source of the protein gluten, which is one of the most essential elements in baking. Actually, there are two proteins found in flour – glutenin and gliadin; which combine together in the presence of moisture to form Gluten. Bakers select flour on the basis of its gluten content. Flours high in gluten are called hard flour and those low in gluten are called weak flour. From the Bakery point of view, we need to learn about 3 types of flour:
1. Bread flour is strong flour, which is used to make bread including hard rolls, and any product that requires high gluten. Bread flour feels rough and slightly coarse when rubbed between the fingers. If squeezed into a lump, it falls apart as soon as the hand is opened. Its color is creamy white.
2. Cake flour is weak or low gluten flour. It has a very soft smooth texture and a pure white color. Cake flour is used for cakes and other delicate products that require low gluten content. Cake flour feels very smooth. It stays in a lump if squeezed in the palm of the hand.
3. Pastry flour is lower in gluten than bread flour but higher than cake flour. It is creamy white in color. Pastry flour is used for piecrusts as well as some sweet dough and for biscuits and muffins. Pastry flour feels the same as cake flour.
All-purpose flour is available in the market and is quite popular in the retail market. This flour is formulated to be slightly weaker than bread flour so that it can be used for pastries as well. A professional baker however prefers to use flours that are formulated for specific purposes, because these give the best results.
WHOLE WHEAT FLOUR (atta)
Whole-wheat flour is made by grinding (milling) the entire wheat kernel, including the bran and the germ (which is the embryo of a new wheat plant). The germ is high in fat content and therefore tends to turn rancid quickly. Whole-wheat flour therefore does not have a very long shelf life like Refined Flour. Since it is made from wheat, whole-wheat flour contains gluten and can be used for bread making. However, bread made from 100% whole-wheat flour will be heavy, as the gluten strands are cut by the sharp edges of the bran flakes. Also, the fat from the wheat germ contributes slightly to the shortening action. This is why most whole wheat breads are strengthened with refined flour.
Bran flour is flour to which bran flakes have been added. The bran may be coarse or fine depending upon the specification.
RYE FLOUR
Next to Whole and White Wheat Flour, Rye is the most popular flour used for bread making. Rye flour does not develop gluten and breads made with it will be heavy unless some hard wheat flour is added to it. Rye flour is available in three shades: light, medium and dark. Rye meal or pumpernickel is a coarse meal made from the whole rye grain. It looks like oatmeal. Rye blend is a mixture of rye flour and hard wheat flour.
OTHER FLOURS
Products milled from other grains are occasionally used to add variety to baked goods. These include corn meal, buckwheat, soy flour, potato flour, oat flour and barley flour. The term meal is used to describe products that have not been as finely ground as flour. All these products must be used along with wheat flour as the do not form sufficient gluten.
STARCHES
In addition to flour, some other starch products are used in the bakery. Unlike flour, they are used primarily as thickening agents for pies, puddings and fillings.
1. Cornstarch has a special property that makes it valuable for certain purposes. Products thickened with cornstarch set almost like gelatin when cooled.
2. Waxy maize also has valuable properties. They do not break down when frozen and are good for products that need to be frozen and stored. Also, it is very clear when cooked and give a brilliant clear appearance.
3. Instant Starches are those which have been pre cooked or pre gelatinized, so they will thicken cold liquids without further cooking. They are useful when heat will damage flavor of the products (strawberries).
BASIC COMMODITIES SUGAR
Sugar occurs naturally in almost all plant structures. However, for general and commercial purposes, it is obtained from two major sources:
- Sugarcane
- Sugar Beet
CLASSIFICATION OF SUGAR
Sugar may be classified under one or a combination of the following:
- The source, sugarcane or sugar beet
- The country of origin
The method of processing which in
turn will determine the type of sugar produced, e.g: cube sugar, powdered sugar
- Its uses e.g. specific sugars are bought for certain purposes like icing sugar is meant basically for icings.
- The chemical group – sugars may be classified into two chemical groups
Mono saccharides &
di saccharides
MARKET FORMS OF SUGAR
Commercially, sugar is available in two forms:
- Solid
- Liquid
SOLID FORMS
1. Granulated sugar: By far the most important sugar product on the market and is also known as sucrose. Granulated sugar is marketed as fine (the type most commonly used) or ultra fine (used in the making of cakes and instant beverages).
2. Powdered sugar: This is obtained from granulated sugar, thru the process of pulverization. It is available in various degrees of fineness depending on the purpose that it is used for.
3. Brown sugar (perish the thought, it’s not what you are thinking!): is composed of sugar crystals which are suspended in flavored and colored molasses syrup and is often referred to as demerara sugar. Demerara sugar is brown sugar that comes from demerara in the West Indies.
4. Cube sugar: This is ultra fine granulated sugar which is compressed into small individual portion sized cubes. Very popular in fine dining restaurants. Sometimes is made out of powdered sugar as well.
5. Icing sugar: This is powdered sugar which has a small percentage of cornflour worked into the mixture. It gives a much smoother texture to the final product and as the name suggests, it’s used to produce various icings.
6. Maltose: Also known as malt sugar is used as a sweetener, flavoring and coloring agent. It is also used in the manufacture of beer besides being used in malt beverages, instant beverages, milk shakes and candy.
7. Lactose: Lactose is commercially extracted from solutions of whey, by crystallization. It is added to bakery products because its presence contributes to the surface browning of baked products.
8. Invert sugar: Invert sugars are desirable in baked products and in candies because they resist crystallization and also retain their moisture.
LIQUID FORMS
Liquid sugars are available in the form of syrups. These syrups are liquid containing large amounts of sugar. Syrups can have a variety of flavors that make them a useful addition to other foods. The most frequently used syrups are:
1. Molasses: known commonly here in India as jaggery(gur), but in the liquid form. It is a by-product of the sugar industry (sugarcane). However, black jaggery is obtained from the date palm and is also referred to as palm jaggery. In the manufacture of sugar from cane, the sugar goes thru various stages of crystallization and refinement. The left overs and by products are used to produce molasses.
2. Maple syrup: Maple syrup is obtained from the sap of mature sugar maple trees. The characteristic flavor of maple syrup is obtained from the volatile oils in the sap that is then concentrated by boiling. Maple syrup is very popular in the USA where it is popularly served with flapjacks (American pancakes). It is also popular in Canada and the maple leaf even figures on the Canadian flag.
3. Honey: is made by bees from the nectar of flowers and is stored for future use in cell like structures called honeycombs. One property of honey that is very useful in cookery and bakery is its ability to retain water. Cakes and cookies that have honey as an ingredient will retain their moisture for a fairly longer time.
4. Corn syrup: Is used mainly to sweeten foods in the commercial production of foodstuffs. Corn syrup is a liquid sweetener consisting mainly of glucose or dextrose. It is made by converting cornstarch into simple sugar compounds by the use of enzymes.
5. High fructose corn syrup: This product is being used increasingly in commercial food production because of its intense sweetness. It is used in the manufacture of soft drink concentrates, fruit squashes, candy and some bakery products.
6. Glucose: is present in fruits in the natural form but commercially is sold as dextrose. It is used extensively in the commercial production of candy. It is also used widely in making Icings like gum paste, pastillage and such products.
FUNCTIONS OF SUGAR
1. As a sweetener in products such as cakes, cold drinks and commonly in tea and coffee.
2. To soften gluten in flour and to make baked products more tender to eat and lighter in texture.
3. To color baked products such as the crust of bread.
4. To retain moisture and prevent baked products in particular from drying out quickly.
5. To act as a preservative in jams, marmalades and canned fruit.
6. To help as an activator. Sugar helps yeast to grow faster by providing it with a readily available source of food and nourishment.
7. As an anti coagulant, sugar helps to delay the coagulation of protein in egg.
8. It is used as the main ingredient in icings and candies.
- Its uses e.g. specific sugars are bought for certain purposes like icing sugar is meant basically for icings.
- The chemical group – sugars may be classified into two chemical groups
Mono saccharides &
di saccharides
MARKET FORMS OF SUGAR
Commercially, sugar is available in two forms:
- Solid
- Liquid
SOLID FORMS
1. Granulated sugar: By far the most important sugar product on the market and is also known as sucrose. Granulated sugar is marketed as fine (the type most commonly used) or ultra fine (used in the making of cakes and instant beverages).
2. Powdered sugar: This is obtained from granulated sugar, thru the process of pulverization. It is available in various degrees of fineness depending on the purpose that it is used for.
3. Brown sugar (perish the thought, it’s not what you are thinking!): is composed of sugar crystals which are suspended in flavored and colored molasses syrup and is often referred to as demerara sugar. Demerara sugar is brown sugar that comes from demerara in the West Indies.
4. Cube sugar: This is ultra fine granulated sugar which is compressed into small individual portion sized cubes. Very popular in fine dining restaurants. Sometimes is made out of powdered sugar as well.
5. Icing sugar: This is powdered sugar which has a small percentage of cornflour worked into the mixture. It gives a much smoother texture to the final product and as the name suggests, it’s used to produce various icings.
6. Maltose: Also known as malt sugar is used as a sweetener, flavoring and coloring agent. It is also used in the manufacture of beer besides being used in malt beverages, instant beverages, milk shakes and candy.
7. Lactose: Lactose is commercially extracted from solutions of whey, by crystallization. It is added to bakery products because its presence contributes to the surface browning of baked products.
8. Invert sugar: Invert sugars are desirable in baked products and in candies because they resist crystallization and also retain their moisture.
LIQUID FORMS
Liquid sugars are available in the form of syrups. These syrups are liquid containing large amounts of sugar. Syrups can have a variety of flavors that make them a useful addition to other foods. The most frequently used syrups are:
1. Molasses: known commonly here in India as jaggery(gur), but in the liquid form. It is a by-product of the sugar industry (sugarcane). However, black jaggery is obtained from the date palm and is also referred to as palm jaggery. In the manufacture of sugar from cane, the sugar goes thru various stages of crystallization and refinement. The left overs and by products are used to produce molasses.
2. Maple syrup: Maple syrup is obtained from the sap of mature sugar maple trees. The characteristic flavor of maple syrup is obtained from the volatile oils in the sap that is then concentrated by boiling. Maple syrup is very popular in the USA where it is popularly served with flapjacks (American pancakes). It is also popular in Canada and the maple leaf even figures on the Canadian flag.
3. Honey: is made by bees from the nectar of flowers and is stored for future use in cell like structures called honeycombs. One property of honey that is very useful in cookery and bakery is its ability to retain water. Cakes and cookies that have honey as an ingredient will retain their moisture for a fairly longer time.
4. Corn syrup: Is used mainly to sweeten foods in the commercial production of foodstuffs. Corn syrup is a liquid sweetener consisting mainly of glucose or dextrose. It is made by converting cornstarch into simple sugar compounds by the use of enzymes.
5. High fructose corn syrup: This product is being used increasingly in commercial food production because of its intense sweetness. It is used in the manufacture of soft drink concentrates, fruit squashes, candy and some bakery products.
6. Glucose: is present in fruits in the natural form but commercially is sold as dextrose. It is used extensively in the commercial production of candy. It is also used widely in making Icings like gum paste, pastillage and such products.
FUNCTIONS OF SUGAR
1. As a sweetener in products such as cakes, cold drinks and commonly in tea and coffee.
2. To soften gluten in flour and to make baked products more tender to eat and lighter in texture.
3. To color baked products such as the crust of bread.
4. To retain moisture and prevent baked products in particular from drying out quickly.
5. To act as a preservative in jams, marmalades and canned fruit.
6. To help as an activator. Sugar helps yeast to grow faster by providing it with a readily available source of food and nourishment.
7. As an anti coagulant, sugar helps to delay the coagulation of protein in egg.
8. It is used as the main ingredient in icings and candies.
AERATING AGENTS –BAKERY NOTES
Aeration renders bakery products more attractive, more appetizing and
digestable. In order to aerate a pressure must be induced within the product
and a resistance offered to it so the volume may be increased during baking
until such time as the proteins coagulate and the volume is maintained without
collapsing.
There are five methods of aeration--------
1. Panary-----yeast
2. Chemical------ baking powder.
3. Physical-------whisking and baking.
4. Lamination-----rolling and folding .
5. .Combination --- of the above.
Panary-----
The principle of panary fermentation is the production of carbon-dioxide. This is brought about by the action of enzymes in yeast and flour.The initial gas production comes from the breakdown of glucose present in the flour or contained in the added ingredients. Further glucose is made available by the conversion of other carbohydrates by specific enzymes. The gas is entangled and held in the gluten network which is gradually made more elastic during the fermentation process and so the dough rises.There are acids and alcohol by-products in the fermentation process which contribute to the flavour.
In the oven the gas production is accelerated until at last the yeast is killed and activity ceases the expansion of air and gas and the pressure of water vapour causes an increase in volume which is maintained by the coagulation all the proteins present as bakeing proceed.
Chemical:-
Various chemical substances are used for aerating cakes. All of them when moistened and heated produce gas which by becoming entangled in gluten network of the mixture from which it readily cannot escape, causes the of volume of cake to increase while in the early stages of baking in the oven.
Baking pd can be defined as any substance or mixture of substance which may be purchased at an economical price, which when moisten and heated will produce a gas to aerate confectionary and which will leave a harm less and practically tasteless residue in the goods.
Sodium bicarbonate or baking soda is used either alone or mixed with an acid of some kind to provide the necessary gas for aeration twice as much gas carbon dioxide is produced from a given lot of sodium bicarbonate. When suffcient acid is present to release al the gas contained in it compared with amount of gas given off when NaHCO3 is moistened and heated without the precence of an acid.
NaHCO3 is used alone in the aeration of some kinds of confectionary, chiefly in cakes which are strongly flavoured and which have dark coloured crumb {ginger cake}
2NaHCO3 = Na2CO2 + H2O + CO2
Soduim bicarbonate = Sodium Carbonate + water + Carbondioxid
Cream Of Tartar Sodium Bicarbonate
In order to obtain all the gas which is available in any definite quantity of so NaHCO3 and acid must be used along with it. The acid substance is generally potassium hydrogen tartrate commonly called cream of tarter. When mixed in the correct proportion and heated in water they produce CO2 , water and potassium sodium tartrate Rochelle salt.
KHC4H6O6 + NaHCO3 = KNaC4H4O6 +CO2 + H2O
The combining weight used in bakery is usually two parts of cream of tarter and one part of sodium bicarbonate but these leaves an access alkalie in the goods {from the above equation it is seen that 22.4 part cream of tarter required 10 parts sodium bicarbonate for complete neutralasation} 2:1 ratio has insufficient cream of tarter to neutralize all the sodium bicarbonate in other words a small quantity of sod does not enter the reaction this excess acts as stated previously leaving a residue of NaCO3 in the goods which affects crumb colour it is for this reason that for all good recipe for white crumb cakes an extra quantity of cram of tarter is added is used.
Baking powder can be made with 11 ¾ lbs cream of tartar and 5/4 lbs sodium
bicarbonate to give an all round result
Physical-----
Long ago in our gastronomic history it was discovered that by beating a mixture air was incorporated and the baked product became lighter in texture. There are two important bakery materials that are capable of holding air when beaten, they are eggs and fats.
The principle behind physical aeration is that the rapidly moving hand whisk or beater breaks the surface on impact and moves into the mixture, temporarily extending the surface area.
The surface area will strive to remain at a minimum thus offering a resistance which drives the mixture behind the beating equipment as it penetrates still further into the mix.
It is during this fractional moment of time before the beater strikes again that air bubbles are drawn into the mixing until at last it is thoroughly aerated ,
Lamination--------
The purpose of rolling and folding is to build up a laminated structure of alternating layers of dough and fat. This build up is known as aeration by lamination. Gluten is insoluble wheat protein, hydrated in the ratio of one part protein and two parts water
IT is the changing of water into steam and the consequent pressure within the gluten structure that is largely the reason for the lift. When the pastry is baked the fat melts and forms an oily layer between the leaves of the dough and preventing them from sticking together; the heat penetrates further into the the paste, the water in the doughy layers is
Changed into steam distending the gluten films of the dough and so pushes the lubricated leaves of the dough apart. This produces a great increase in the volume.Later the gluten of the flour is coagulated while the water in the dough dries out so that by the time the paste is properly baked it is able to retain its distended puffy volume Temperature of the oven is important. If baked in too cool an oven the paste will not puff up to the fullest extent.
Combination of methods--------
Combination of two of the above are used to produce different types or differing qualities of confectionery.
Danish pastry is a combination of aeration by yeast and by lamination.
There are five methods of aeration--------
1. Panary-----yeast
2. Chemical------ baking powder.
3. Physical-------whisking and baking.
4. Lamination-----rolling and folding .
5. .Combination --- of the above.
Panary-----
The principle of panary fermentation is the production of carbon-dioxide. This is brought about by the action of enzymes in yeast and flour.The initial gas production comes from the breakdown of glucose present in the flour or contained in the added ingredients. Further glucose is made available by the conversion of other carbohydrates by specific enzymes. The gas is entangled and held in the gluten network which is gradually made more elastic during the fermentation process and so the dough rises.There are acids and alcohol by-products in the fermentation process which contribute to the flavour.
In the oven the gas production is accelerated until at last the yeast is killed and activity ceases the expansion of air and gas and the pressure of water vapour causes an increase in volume which is maintained by the coagulation all the proteins present as bakeing proceed.
Chemical:-
Various chemical substances are used for aerating cakes. All of them when moistened and heated produce gas which by becoming entangled in gluten network of the mixture from which it readily cannot escape, causes the of volume of cake to increase while in the early stages of baking in the oven.
Baking pd can be defined as any substance or mixture of substance which may be purchased at an economical price, which when moisten and heated will produce a gas to aerate confectionary and which will leave a harm less and practically tasteless residue in the goods.
Sodium bicarbonate or baking soda is used either alone or mixed with an acid of some kind to provide the necessary gas for aeration twice as much gas carbon dioxide is produced from a given lot of sodium bicarbonate. When suffcient acid is present to release al the gas contained in it compared with amount of gas given off when NaHCO3 is moistened and heated without the precence of an acid.
NaHCO3 is used alone in the aeration of some kinds of confectionary, chiefly in cakes which are strongly flavoured and which have dark coloured crumb {ginger cake}
2NaHCO3 = Na2CO2 + H2O + CO2
Soduim bicarbonate = Sodium Carbonate + water + Carbondioxid
Cream Of Tartar Sodium Bicarbonate
In order to obtain all the gas which is available in any definite quantity of so NaHCO3 and acid must be used along with it. The acid substance is generally potassium hydrogen tartrate commonly called cream of tarter. When mixed in the correct proportion and heated in water they produce CO2 , water and potassium sodium tartrate Rochelle salt.
KHC4H6O6 + NaHCO3 = KNaC4H4O6 +CO2 + H2O
The combining weight used in bakery is usually two parts of cream of tarter and one part of sodium bicarbonate but these leaves an access alkalie in the goods {from the above equation it is seen that 22.4 part cream of tarter required 10 parts sodium bicarbonate for complete neutralasation} 2:1 ratio has insufficient cream of tarter to neutralize all the sodium bicarbonate in other words a small quantity of sod does not enter the reaction this excess acts as stated previously leaving a residue of NaCO3 in the goods which affects crumb colour it is for this reason that for all good recipe for white crumb cakes an extra quantity of cram of tarter is added is used.
Baking powder can be made with 11 ¾ lbs cream of tartar and 5/4 lbs sodium
bicarbonate to give an all round result
Physical-----
Long ago in our gastronomic history it was discovered that by beating a mixture air was incorporated and the baked product became lighter in texture. There are two important bakery materials that are capable of holding air when beaten, they are eggs and fats.
The principle behind physical aeration is that the rapidly moving hand whisk or beater breaks the surface on impact and moves into the mixture, temporarily extending the surface area.
The surface area will strive to remain at a minimum thus offering a resistance which drives the mixture behind the beating equipment as it penetrates still further into the mix.
It is during this fractional moment of time before the beater strikes again that air bubbles are drawn into the mixing until at last it is thoroughly aerated ,
Lamination--------
The purpose of rolling and folding is to build up a laminated structure of alternating layers of dough and fat. This build up is known as aeration by lamination. Gluten is insoluble wheat protein, hydrated in the ratio of one part protein and two parts water
IT is the changing of water into steam and the consequent pressure within the gluten structure that is largely the reason for the lift. When the pastry is baked the fat melts and forms an oily layer between the leaves of the dough and preventing them from sticking together; the heat penetrates further into the the paste, the water in the doughy layers is
Changed into steam distending the gluten films of the dough and so pushes the lubricated leaves of the dough apart. This produces a great increase in the volume.Later the gluten of the flour is coagulated while the water in the dough dries out so that by the time the paste is properly baked it is able to retain its distended puffy volume Temperature of the oven is important. If baked in too cool an oven the paste will not puff up to the fullest extent.
Combination of methods--------
Combination of two of the above are used to produce different types or differing qualities of confectionery.
Danish pastry is a combination of aeration by yeast and by lamination.
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