CHAPTER 7: GLUTEN Flashcards
(228 cards)
1
Q
Is gluten one one the three main structure builders in baked goods?
A
Yes, egg proteins and starch are the other two.
2
Q
What is the most difficult structure builder to control? Why? What about in yeast doughs?
A
Gluten, because small changes in a formula or mixing method have large effects on gluten development.
3
Q
Why is gluten important especially important in yeast baked doughs?
A
They rely heavily on gluten for unbaked dough structure. Without gluten, yeast-leavened dough is not good at retaining gases produced during the fermentation process. The dough does not expound well, if at all, and the expansion does not hold throughout the baking process. Cell wall tear, and the final crumb is dense.
4
Q
Flour consists mainly of a solid what?
A
Solid matrix of proteins embedded with starch granules.
5
Q
What proteins are unique to the wheat endosperm?
A
Gliadin and glutenin.
6
Q
What happens to gliadin and gluten when water is added to flour?
A
They absorb water and swell.
7
Q
Does mixing promote the absorption of water? How?
A
Yes, by exposing new surfaces of flour to particles of water.
8
Q
Besides water absorption, how else does mixing help (3 things)?
A
It incorporates oxygen, which oxidizes and strengthens gluten; wears down particles, until they are small and no longer spherical; distributes particles evenly throughout the dough, so that ultimately a strong, continuos gluten network form.
9
Q
Does gluten become stronger as it is mixed?
A
Yes
10
Q
Gluten–and dough–is considered fully developed when it is what?
A
Strong, cohesive and elastic.
11
Q
Glutenin is thought to provide what?
A
The strength and cohesiveness of the gluten network, as well as its springiness or elasticity.
12
Q
Gliadin is thought to contribute what?
A
Stretchiness and extensibility.
13
Q
Why should dough be mixed evenly in all direction when gluten is involved?
A
Because gluten strands align in the directions they are mixed.
14
Q
How must dough be kneaded by hand? What if it’s laminated dough?
A
Dough must be turned 90º with every knead. Likewise, when laminated doughs are folded or sheet, the dough is rotated with each fold or run through the sheeter. Otherwise, gluten strands align in one direction. This becomes especially evident when dough is not allowed to relax before being shaped and baked.
15
Q
How can you tell if dough hasn’t been kneaded properly before being shaped and baked?
A
The dough will tend to shrink in whatever direction that the gluten strands are oriented.
16
Q
The backbone of the gluten network consists largely of what? What does it look like? What about gliadin?
A
The largest glutenin molecules, or subunits, aligned and tightly linked to on another. These tightly linked glutenin subunits associate more loosely, along with gliadin, into larger gluten aggregates.
17
Q
Portions of ________ are thought to loop, making gluten stretchy and flexible.
A
glutenin
18
Q
Gluten is further made flexible by the presence of compact, coiled _______ molecules interspersed throughout.
A
gliadin
19
Q
At the next level of gluten structure, gluten aggregates interact to form a tangled network of larger gluten particles that loosely interact with what?
A
Starch granules, fats, sugars, and gums.
20
Q
Altogether, does it seems like gluten structures are held together by some very strong and many more weak bonds that break and reform easily? Explain.
A
Many bonds break, in particular, during mixing, only to reform around the surfaces of expanding air bubbles during proofing and the early stages of baking. It is this combination of strong and weak forces breaking and reforming that contributes to the unique nature of gluten.
21
Q
Fully developed dough has what type of appearance?
A
Dry, silky appearance. It stretches into a smooth, thin film without tearing or breaking, yet still retains some ability to spring back.
22
Q
Bakers use what test to see if dough is fully developed?
A
Windowpane test.
23
Q
How do you make a windowpane?
A
Pull off a piece of dough about 1 inch or so in diameter. Roll it between your hands to shape into a ball, then gently pull the dough between your hands. Rotate the dough as you do this so that you are pulling it in all direction, forming a paper thin sheet of dough. Fully developed dough should form a thin film without tearing.
24
Q
Although changes to gluten network cannot be seen, what happens, how are they reflected by what is seen?
A
Batters and doughs become smoother, stronger, and less lumpy as they are mixed and kneaded, and they are better able to stretch and trap solid particles, liquids, and gases as they expand.
25
When batters and doughs are baked, what happens to most of the moisture?
It's either absorbed by gelatinized starch granules or evaporates.
26
With the loss of moisture and in the presence of heat, what happens to gluten? Is it unique to gluten?
Gluten coagulates into a firm and rigid yet porous structure that holds up its shape. While not unique to gluten (egg proteins, when heated, also coagulate into a firm,rigid structure), this is nonetheless and important feature of gluten.
27
Can doughs have too much gluten? What is it called when dough is too tight and bouncy?
Yes, it's usually called "bucky."
28
What is the problem with "bucky" dough?
Bread tends to be tough and chewy, have a low volume because they cannot stretch, and develop soft and thin crusts.
29
What happens of parties have too little gluten?
Pie crusts crumble easily, cakes collapse and baking powder biscuits slump.
30
Gluten's makeup and structure are responsible for its unique nature, which scientists describe as what?
Viscoelastic
31
What is viscoelasticity?
The ability of a material to stretch and easily change shape--like a thick of viscous liquid--without breaking or tearing, and to partly bounce back to its original shape--like a rubber band.
32
Viscoelastic products can be thought of as what?
Part liquid, part solid.
33
What requires the most gluten of all baked goods?
Yeast-raised breads.
34
Gluten is so important to bread making that when bakers speak of flour, they are generally referring to what?
The amount of quality gluten that form from flour.
35
Is corn syrup viscoelastic? Why?
No, it does not have elasticity or rubberiness; it cannot bounce back to original shape once it flows. Also not strong enough to hold gas bubbles.
36
Is shortening viscoelastic? Why?
No, it cannot stretch or flow like liquid. While it's soft enough to change shape and hard enough to hold, it cannot stretch and hold expanding gases.
37
Is peanut brittle viscoelastic? Why?
No, it is too firm and rigid. While it holds its shape quite nicely, PB will not stretch or change shape easily. If gases were able to expand at all in PB, the brittle would crack and shatter from buildup of pressure.
38
Is bread dough made from high-quality flour best at holding gases produced during fermentation and oven spring?
Yes
39
Of common breads, which usually require the most gluten if high volume is desired?
Hearth breads - those that are baked directly on sheet pans or baking stones.
40
What happens to hearth breads without sufficient gluten or pans to hold them in shape?
They collapse on themselves.
41
With less gluten, does a dough break and tear more readily?
Yes, it's why you have larger air pockets in rustic, artisan breads.
42
Should flour quality be judges by its intended use?
Yes
43
Are high-gluten flours often described as high quality? How is this wrong?
Yes, but all baked products don't necessarily need high amounts of gluten.
44
Describe high quality pastry flour.
Typically low in gluten, has a very fine granulation, is relatively low in pentosans and other gums, and has few damaged starch granules.
45
Is "high-quality" flour particularly high in nutritional value? Why?
No, because it is white flour and contains no bran or germ particles. Which means it's not a good source of dietary fiber and low in lysine (no complete proteins).
46
Do wheat germ proteins form gluten?
No
47
Why is it difficult to compare the gluten requirements of various pastries?
They are complex mixtures of tenderizers and tougheners, moisteners and driers.
48
Is it safe to say that products containing significants amounts of other structure builders require less gluten?
Yes
49
Why do liquid shortening cakes require very little gluten?
They rely on a soft structure of gelatinized starch.
50
Why do sponge cakes not require much gluten?
Their high egg content.
51
Three main ways gluten is developed during baking.
Mixing and kneading, chemical dough development, over time during bulk fermentation and final proof.
52
Mixing and kneading is sometimes called what?
Mechanical dough method.
53
What is chemical dough development?
Use of ascorbic acid and other maturing agents that strengthen.
54
Besides the main three, are the other ways of controlling gluten development? List ingredients and methods.
- type of flour
- amount of water
- water hardness
- water pH
- mixing and kneading
- batter and dough temperature
- fermentation
- maturing agents and dough conditioners
- reducing agents
- enzymes
- tenderizers and softeners
- salt
- other structure builders
- milk
- fiber, bran, fruit pieces, spices, and the like
*Most items tend to have their greatest effect on baked goods that rely heavily on gluten, and not eggs and starch, for structure.
55
Of the last list, what items apply exclusively to yeast-raised doughs?
Heat-treated milk and dough conditioners. The others apply to all baked goods.
56
What items off the list will only affect high-ratio liquid shortening cakes and other baked goods made from cake flour?
Fats, sugars, and water pH - they have a larger affect on structure builders like eggs and starch in liquid shortening cake.
57
Is the type of flour important in gluten control?
Yes
58
Why is the type of grain important?
Because wheat flour is the only common grain with the potential for forming a good amount of high-quality gluten.
59
Does rye have the same amount of protein?
Yes, but very little of it is gluten forming.
60
Do oat, soy, corn or buckwheat form gluten?
No
61
Do different varieties of wheat vary in the amount of quality gluten that forms from them?
Yes
62
Thousands of different wheat varieties are classified as what two things?
Soft wheats or hard wheats.
63
What wheat is typically low in protein, and the protein quality is typically poor (from the standpoint of gluten development)? Explain.
Soft wheat has a lower amount of glutenin for the amount of gliadin, and the glutenin subunits tend to be smaller in size. Soft wheat forms gluten that is weak and tears easily.
64
Why are hard wheats good for gluten development?
They are high in protein, contain a higher percentage of glutenin for the amount of gliadin, and the glutenin subunits tend to be large in size. Strong wheat flours form gluten that is strong, cohesive, and elastic.
65
Is the amount of protein dependent on environmental conditions?
Yes, such as climate, solid quality, and the amount of fertilizer applied.
66
Why does whole wheat flour not produce the same gluten as white flour?
Bran and germ interfere with gluten development, and that protein from these components does not form gluten.
67
Glutenin and gliadin are found exclusively in what part of the wheat?
Endosperm
68
What is an alveograph?
Machine that blows air into dough made from flour, water, and salt, forming an expanding bubbles. This mimics the fermentation process. Three values are measured: dough strength, dough tenacity, and extensibility.
69
What is dough tenacity?
A measure of the pressure reached as the bubble inflates
70
Is the amount of water important for gluten development?
Yes
71
How much do glutenin and gliadin swell when contact with water is made?
Two times their weight in water.
72
Should you worry about adding water to biscuits and pie doughs?
Yes, low water is what keeps them tender.
73
What does adding excess water do to cake batters? Form more gluten?
Cake batters are more fluid and have plenty of water already; adding more won't create more gluten development. Instead, adding more water dilutes out proteins, weakening gluten.
74
Does oil interfere with gluten development?
Yes, it's a tenderizer.
75
Is water always added in as an ingredient in its own right?
No, other items such as eggs, milk etc contain water.
76
Does water hardness affect gluten?
Yes
77
What is water hardness?
The measure of the amount of mineral, like calcium and magnesium, in water.
78
Does hard water have high or low minerals?
High, and soft water has low.
79
How do you know (by sight) if water is hard or soft?
If you ever see hard white mineral deposits, called scale, on equipment surfaces, you know the water is hard.
80
Do minerals strengthen gluten? What does this do to yeast breads?
Yes, which causes them to become too strong and elastic; they do not stretch when gas expands or they quickly bounce back.
81
What happens to doughs prepared from soft water?
They are often too soft, slack, and sticky. Ideally, water for bread baking isn't too hard or soft.
82
What effect does gluten have on hole size if it's weak and tears easily?
It creates appealing large, irregular holes.
83
How do bakers achieve these large, irregular holes?
Using low protein flour and a lot of water, sometimes or 70 percent bakers percentage, compared with 50-60 percent for irregular lean dough.
84
What kind of dough is created with excess water?
A well-hydrated dough that is a cross between batter and dough.
85
Is well-hydrated dough messy to work with?
Yes, but it can produce fine artisan breads.
86
Not only is the grain coarsened by additional water but a longer bake time is needed to what?
Dry out the bread, resulting in a thicker, crisper crust.
87
Why are soft waters hard and others soft? Think ground water vs surface water.
Water becomes hard as it picks up minerals from contact with the earth. Ground water, which percolates through soil on its way to water wells, is usually harder than surface water from lakes and reservoirs.
88
Since the earth varies in composition from one location to the next, does water hardness also vary?
Yes
89
How do you compensate for water that is too hard or soft?
They have dough conditioners designed for this.
90
How do dough conditioners for soft water work?
They contain calcium salts, such as calcium sulfate, to increase the mineral content.
91
How do dough conditioners for hard water work?
They contains acids that prevent minerals from interacting with gluten.
92
A more common solution for hard water.
Treat all incoming water with a water softener system.
93
What do water softeners do? Two benefits.
Remove calcium and magnesium from the water. This not only stops minerals from strengthening gluten but also eliminates damage to equipment from scale buildup.
94
Setback to water that is treated with a water softener (think blood pressure).
Water treated with water softener is high in sodium, which in some people can contribute to high blood pressure.
95
Does water pH affect gluten?
Yes
96
pH is a measure of what?
Acidity or alkalinity or water.
97
The pH scale runs fro 0 to what?
14
98
At pH 7, water is what?
neutral - neither acidic or alkaline (basic).
99
Do water supplies usually have a pH of 7?
Rarely
100
Which areas of North America and Canada are plauged by acidic rain?
Along the Atlantic coast. This means there water has a low pH.
101
The ideal pH for maximum gluten development is what?
Slightly acidic, at a pH around 5-6.
102
Will adding acid so pH drops below 5, or adding alkali so it rises above 6, change gluten?
Yes, it weakens gluten.
103
Examples of acids commonly added to baked goods.
Cream of tartar, fruits and fruit juices, cultured dairy products, and vinegar.
104
Why would acid be added to a strudel dough?
Dissolve gluten and reduce its strength, so that the dough is more extensible and easier to stretch without tearing.
105
An example of an alkali added to baked goods.
Baking soda.
106
Although water hardness and pH are completely different concepts, can they influence each other? Explain.
Yes, certain minerals that increase water hardness also increase pH. Some acids that decrease pH also decrease the effects of water hardness.
107
Orange juice and honey are acidic or alkaline?
Acidic (3.5)
108
Bananas and pumpkin are acidic or alkaline?
Acidic (5.2)
109
Do mixing and kneading affect gluten?
Yes
110
Can too much mixing develop too much gluten?
Yes
111
For all products except for yeast-raised doughs, over-mixing refers to what?
Toughening from too much gluten.
112
What happens to the viscosity of most cookie dough when heated in the oven? What stops this? Explain.
Their constancy becomes liquid and the dough will spread. At a certain temperature, heat sets the gluten and egg proteins so that the dough thickens and stops spreading.
113
How much baking soda should be added to cookies?
As little as 0.25 to 0.5 ounce (5 to 15 grams) for 10lbs (4.5 kilograms) of cookie dough.
114
What happens when baking soda is added to cookies?
It increases the cookies spread by increasing pH of the dough, raising the set temperature of gluten and egg proteins. With more free water and less structure for longer time, cookies that contain baking soda spread more and have a coarser, more porous crumb. Since moisture evaporate from a porous crumb more easily, baking soda provides a crisper crumb as well.
115
Baking soda increases browning significantly, and if you use it at too high a level, it leaves a district what?
Salty-chemical taste. Too much also causes eggs in baked goods to turn a grayish green.
116
Should you use baking soda at high altitudes when baking cookies? Why?
No, the lower air pressure at high altitudes already encourages spread.
117
Why do tunnels form in over-mixed muffins? How does this happen?
Tunnels are a defect that occurs when over mixing develops too much gluten in muffins. When over mixed batter is baked, evaporated gases have difficulty escaping from the product. Thick, gluten-reinforced cell walls prevent muffins from slowly letting off steam. Instead, gas builds up, until finally enough pressure forces them to escape upward, much like a volcano erupts.
118
Are traditional muffin batters low in tenderizing fats and sugars?
Yes
119
How are traditional muffins kept from toughening?
They are mixed just long enough to dampen flour.
120
Two ways to avoid "tunnels" in muffins.
One, don't over mix the batter. Two, use soft flours and add tenderizers to the formula, making it difficult to over mix.
121
Why do todays muffins often resemble tender cupcakes than coarse-grained, rustic muffins of yesterday?
Pastry or cake flour and lots of tenderizers are added in todays version.
122
Do baking powder biscuits require some gluten? How much?
Yes, light mixing or kneading is needed allows biscuits to remain tender but still hold their shape. Too little mixing, and the biscuits slump during baking from lack of structure. Too much mixing, and they hold their shape but are tough.
123
If high-ratio liquid shortening cakes can't develop much gluten, why must you still mix them properly?
They rely on proper mixing for adequate air incorporation and leavening.
124
The longer and more vigorously bread doughs are mixed, the more _______ _______ development takes place.
Mechanical dough
125
What happens if you mix bread dough beyond mechanical dough development?
Gluten networks break down. This is sometimes called the letdown stage, and it is what is meant by over-mixed yeast dough.The dough becomes soft and sticky, it tears into stringy pieces when stretched and it no longer retains water or gas.
126
Bread made with over-mixed dough suffers from what?
Poor loaf volume and a coarse crumb.
127
Dough most susceptible to over-mixing.
Those that do not develop strong gluten to begin with; doughs made from rye flour, low-quality wheat flours, or those high in sugar and fat are least resistant to over mixing.
128
Do different flour require different mixing times? Explain.
Yes, hard flours that are high in glutenin tolerate, even require, longer mix times than flours that are soft. Rye flour, which contains glutenin, is very easily over-mixed. Rich yeast doughs require less mixing to fully develop and are highly susceptible to over-mixing. Finally, dough that will undergo a long bulk fermentation should be mixed for less time, since fermentation also contributes to dough development.
129
Are batter and dough temperature a factor in controlling gluten development?
Yes
130
Dough temp is often controlled through what?
Temperature of ingredients, especially water and other liquids.
131
The warmer the temperature of the liquids, the faster flour particles ______ and protein ________.
Hydrate, oxidizes.
132
Faster hydration and oxidation means what for gluten?
Faster gluten development.
133
Besides gluten, what else is controlling temp good for in yeast raised doughs?
Yeast fermentation.
134
Ideal dough temp for fermentation. What happens if temps are too high?
70º-80ºF (21º-22ºC). If temps are too high fermentation occurs too rapidly and flavor suffers.
135
What does cold liquid in pie pastry dough do?
Minimizes gluten development and prevents solid fat in dough from melting.
136
Does fermentation affect gluten development?
Yes
137
Fermentation involves what?
Allowing yeast in dough to convert sugars into carbon dioxide.
138
Two separate stages of fermentation. How long does it take?
Bulk fermentation and final proofing - this can take several hours to complete.
139
Does fermentation contribute to dough maturation?
Yes, it strengthens gluten, improving cohesiveness and elasticity.
140
How does fermentation help gluten? Explain.
The action of expanding air bubbles pushing on gluten. Bonds that were broken during mixing slowly reform around these expanding bubbles
141
Can you ferment dough too long? What happens?
Yes, just like over-mixing you can over-ferment. Dough becomes too soft, sticky and loses its gas retaining abilities.
142
Do maturing agents and dough conditioners affect gluten?
Yes
143
Do some maturing agents weaken gluten?
Yes
144
What does chlorine gas do to gluten?
It weakens gluten but also whitens carotenoids and changes starch so that it absorbs more water.
145
How do scorbutic acid and potassium bromate affect gluten?
They strengthen it.
146
The main role of dough conditioners is what?
Increase gluten strength, contributing to chemical dough development.
147
When are the effects of dough conditioners very important?
Under extreme conditions, like those caused by high-speed commercial equipment.
148
What are the main in dough conditioners?
Maturing agents
149
Typically, how much dough conditioners should be used with flour?
0.2-0.5 percent of the weight of flour.
150
Do reducing agents have the same effect as maturing agents? Explain using ascorbic acid.
No, they have the opposite effect. While maturing agents like ascorbic acid oxide-ze gluten-forming proteins, allowing them to form more bonds, reducing agents alter the gluten-forming protein so that they form fewer bonds.
151
Most common reducing agent used by large-scale commercial bakeries.
L-cysteine
152
What is L-cysteine?
An amino acid naturally found in proteins throughout our bodies. It is a common ingredient in dough conditioners.
153
What is "no-time" dough?
Yeast-raised dough that does no undergo bulk fermentation. Instead it undergoes a quick 10 or 15 minute bench rest before being divided.
154
How are "no-time" doughs able to skip bulk fermentation?
If dough undergoes mechanical dough development by intensive high-speed mixing, or if it undergoes chemical dough development through the use of maturing agents and dough conditioners, less fermentation is needed.
155
How does a regular bakeshop use intensive high-speed mixing for "no-time" dough?
While this requires special equipment, any bakeshop can use chemical maturing agents and dough conditioners to shorten or eliminate bulk fermentation.
156
Is carbon dioxide needed for "no-time" dough?
Yes, they still undergo a final proof so leavening isn't sacrificed.
157
Pros and cons of "no-time" dough.
They take less time to prepare (time is money). The added cost off chemicals is somewhat offset by the higher amount of water absorbed by the doughs. However, breads develop a good amount of flavor during bulk fermentation; bread may lack the subtle flavors that are the pride of a baker.
158
Why is L-cysteine sometimes added to dough during mixing? What is added later to counteract the L-cysteine?
So the dough mixes faster and more easily and generates less frictional heat. The softening and slackening is later counteracted with maturing agents like potassium bromate, which helps rebuild gluten structure during proofing and baking, when structure is needed most.
159
The most potent reducing agent.
Glutathione.
160
What is glutathione? Where is it naturally found?
A fragment protein that is found in fluid mll and many milk products; in active dry yeast and other yeast products that contain dead yeast cells; and in wheat germ.
161
Why do professional bakers seldom use active dry yeast?
When it is used improperly, that is, when water or dough temp is low, glutathione is released into dough and can weaken it.
162
Most bakers prefer what type of yeast?
Compressed or instant yeast, which do not release glutathione.
163
Why is so-called no leavening yeast sold that intentionally contains high amounts of glutathione?
This is sometimes used in large scale bakeries for pizza and tortilla production, so that doughs will stretch more easily and not shrink when baked.
164
Is glutathione also found in wheat germ?
Yes, this is one reason weaker gluten develops from whole wheat flour than from white flour.
165
Can wheat germ be purchased raw or toasted? Does one have less glutathione?
Yes, toasted wheat germ will not have the same high glutathione activity as raw.
166
Does enzyme activity influence gluten?
Yes
167
Amylase is an enzyme that breaks down what?
Starches
168
Proteases are enzymes that break down what?
Proteins such as gelatin and gluten.
169
What happen to gluten when contacted with proteases?
Its broken down into smaller pieces, becoming more soft and extensible.
170
Are proteases used in large scale commercial bakeries?
Sometimes they are used like reducing agents so dough mixes faster and more easily.
171
Does the baker usually add all the proteases?
More often, proteases are not added by the baker, but naturally present in flours.
172
Do malted flours contain proteases?
Flours that have been malted contain many enzymes, including proteases.
173
Does rye flour contain more proteases than wheat flour?
Yes
174
Do whole grains contain more proteases than white flour? Why?
Yes, because whole grains include protein rich bran.
175
Why does clear flour contain more proteases than patent flour?
Because it contains the inner bran layer.
176
Does autolysed dough experience a certain amount of protease activity?
Yes, this is especially true if salt is withheld at this stage, since salt slows enzyme activity.
177
Why is protease activity especially high in sourdough?
Sourdoughs are acidic and have a low pH, and proteases are particular to a low pH.
178
Is protease activity high in a polish or sponge?
Yes
179
What is a poolish or sponge?
A so-called preferment made by adding a small amount of yeast to flour and water well before the bread dough is mixed.
180
Is a poolish made if equal parts flour and water? Does it allow high enzyme activity?
Yes, so it is watery and that allows for high enzyme activity.
181
Does protease activity weakened gluten but also make it more extensible?
Yes
182
Will bread dough made with a polish or that is autolysed stretch more easily? What does this do to the crumb?
Yes, but will also be sticky and tear more easily. This provides volume and a large open crumb.
183
What does the breakdown of protein from protease activity do for flavor?
It releases amino acids that are valuable for the flavor of bread.
184
Do tenderizers and softeners affect gluten?
Yes
185
How do fats, oils, and certain emulsifiers effect gluten?
They work by coating gluten strands (and other structure builders). This reduces gluten development in at least one way.
186
How do sugars tenderize?
By interacting with both water and gluten proteins, keeping gluten proteins from properly hydrating and interacting.
187
Why are sweet doughs, such as brioche, in danger of collapsing?
They contain large amounts of sugar and fat, which halt gluten development. Too little gluten and they won't have the structure needed.
188
Do leavening gases tenderize baked goods? How?
Yes, as the gases expand during baking, they stretch gluten strands--and egg proteins. Stretched gluten strands form thin , weaker cell walls that are easily broken.
189
With the right amount of leavening gases, baked goods are what (think of gluten)?
Weak enough to be pleasantly tender, yet strong enough to keep from collapsing.
190
Does salt affect gluten?
Yes
191
How much salt is usually added to bread?
1.5-2% or so of the weight of flour.
192
Name three functions of salt in baked goods.
Modifies flavor, increase crust color, and controls the rate of yeast fermentation and enzyme activity.
193
Does salt strengthen gluten, improving its cohesiveness and making it less sticky?
Yes
194
Does salt prevent excess tearing of dough?
It prevents excessive tearing when gluten stretches, so bread is easier to handle and has a finer crumb.
195
What size should fat be in pie crust for very flakey crust?
Hazelnuts
196
Does salt bleach flour? Why does bread seem whiter when salt is added?
No, salt acts by strengthening gluten, preventing it from tearing when it stretches from pressure of expanding gases. The result is a fine, even crumb. Light bounces off a fine crumb more evenly than it does off a coarser crumb.
197
Why would you add salt late in the mixing process?
Salt noticeably strengthens gluten, so adding salt to dough made from strong flour may be better at a later stage of mixing. Plus, the dough mixes faster and cooler, since there's less frictional heat generated during mixing.
198
Does dough tighten more when you add salt?
Yes, making it more difficult to stretch but it will stretch further without tearing.
199
Name three starches that partially replace flour in cakes, cookies and pastries.
Rice, corn and potato starches.
200
Why is genoise sometimes made with half cornstarch and half flour?
For tenderness.
201
Unlike gelatinized starch, which contributes to structure, ungelatinized starch granules do what to gluten?
Act as inert fillers that interfere with gluten forming its network.
202
With today's soft cake flour, is it probably unnecessary to use starch to tenderize baked goods?
Yes, except special circumstances.
203
Are eggs structure builders?
Yes
204
Do eggs affect gluten? Do they make baked breads tougher?
Raw eggs in bread dough interfere with gluten development during mixing and fermentation. The final baked bread might be tougher than if eggs were not added, but the added toughening is due to coagulated eggs, not gluten.
205
How much water is in milk?
It's primarily water, about 85-89% water.
206
Does milk affect gluten?
Yes
207
What does milk contain that softens dough?
Glutathione
208
If glutathione is not destroyed in milk, what happens to yeast-raised doughs?
Bread dough softens, and oven spring decreases. The result is a lower loaf volume and a coarser texture.
209
Does heat destroy glutathione?
Yes
210
Is the pasteurization of milk enough to destroys glutathione?
No
211
How do bakers halt glutathione in milk?
Scalding milk at 180ºF and cooling before using in yeast-raised doughs.
212
Have all dry milk solids (DMS) been exposed to enough heat to destroy glutathione?
No, only DMS labeled as high-heat have been heated sufficiently.
213
The milk used in DMS has been heated and held at what temp?
190ºF for 30 minutes prior to drying.
214
Are high-heat DMS the only DMS used in yeast doughs?
Yes
215
Do fiber, bran, fruit pieces, spices, and the like affect gluten?
Yes, any particle that physically gets in the way of forming gluten strands will decrease gluten development. Surprisingly, even spice particles interfere with gluten formation.
216
To rest or relax dough means what?
To let it rest or sit for awhile.
217
Does breed dough usually require a short bench rest before being shaped?
Yes
218
Do laminated doughs, such as croissants, Danish, and puff pastry, usually rest? Is it import?
Yes, usually in the refrigerator between folds. It is important because it makes shaping, rolling and folding dough properly much easier.
219
Bread, croissant and Danish doughs need to rest because gluten is well developed. Explain.
The dough is strong and elastic, meaning it had a tendency to bounce back, which can be a problem when dough is rolled and shaped. The further dough is stretched and worked, the more stressed it is. By relaxing dough, gluten strands have a chance to adjust to new length or shape.
220
How long does bread dough usually relax after mixing.
45 minutes or longer, depending on the dough.
221
Are dough relaxation and dough fermentation the same thing?
No, they should not be mixed up.
222
Whats the difference between relaxation and fermentation?
During fermentation and proofing, yeast continues to produce carbon dioxide gas, slowly stretching gluten strands. The stretching helps further develop gluten and mature the dough. During relaxation, gluten strands are not necessarily stretched, The dough rests, and gluten strands adjust to the new length.
223
Do pie pastry doughs benefit from relaxation? Explain.
Yes, resting after mixing makes it easier to roll and shape. Some pastry chefs also relax rolled and shaped pie dough before baking, so it will not shrink.
224
Why is pie pastry and laminated dough given a rest period in the fridge instead of at room temp?
Chilling solidifies fat, allowing for flakier pastry. Plus some laminated doughs must ferment.
225
What is the third reason pie pastry should rest for several hours after mixing (think water and gluten)? Why?
Pie dough contains little water to stop gluten formation. If water is not mixed properly, dough may become crumbly in some spots and soggy in others. On the other hand, if dough is mixed thoroughly to assure even distribution of water, gluten overdevelops. If instead doughs rests for several hours, water distributed itself evenly throughout the dough. This is important in pie pastry doughs, which are barely mixed and contain little water.
226
Is it important to allow several hours of rest for water absorption when working with grain having large particles, such as durum semolina?
Yes
227
Main thing that happens when doughs relax.
Gluten strands have time to relax and adjust to there new length and shape.
228
At a molecular level, why does dough need a relaxation period?
Gluten consists of a 3D tangled network held together by strong and weak bonds. As dough is rolled and shaped, weak bonds are apt to break, allowing particles to slide past one another. Once rolling and shaping stops, new bonds form and dough takes on a new shape. When dough is stretched and pulled quickly, it doesn't stretch as far as when it's done slowly. Instead, dough resists and is apt to tear. When done slowly, dough has time to make small adjustments on the way.
