Warm Up

1
Warm Up

• Why do bread, cakes and baked goods rise?

2
Leavening Agents

• Chapter 21

3
What is Leavening

• To Leaven means to lighten
• Bubbles of gas cause the mixture to inflate
• Main gasses that leaven are
• Air, Carbon Dioxide and Steam
• Air and steam naturally occur and Carbon dioxide
  is produced by chemicals

4
Air

• Not the main leavening agent in most baked goods
• Principle leavening agent in meringues and angel
  food cake
• Products based on egg foam
• Beating eggs incorporates air into the batter
• Mixed through many means
• Sifting flour, beat fat with sugar and whipping
  batter

5
Steam

• Water in the liquid produces steam
• Recipes that use steam to leaven require very hot
  ovens
• Eggs and Gluten provide the structure of steam
  leavened products
• Steam forms and the batter forms around it

6
Using Carbon Dioxide to Leaven

• Two basic methods for creating Carbon Dioxide
• Baking Soda or Baking Powder create a chemical
  reaction that yields gas
• Using Yeast in a biological process to create the
  gas

7
CO2 Chemically

• Two leavening agents Baking Powder and Baking
  Soda
• They participate in a chemical reaction that
  produces CO2

8
Baking Soda

• The chemical compound sodium bicarbonate
• Releases sodium carbonate and carbon dioxide when
  heated
• sodium bicarbonate gives bad taste and yellowish
  color to baked goods
• Always used with an acid to prevent sodium
  carbonate from forming
• Buttermilk, vinegar, lemon juice, molasses,
  honey, fruit, fruit juices and cream of tartar

9
Baking Powder

• Leavening compound that contains baking soda, dry
  acids and starch or some other filler
• The filler helps absorb moisture in the air,
  which prevents the chemical reaction from taking
  place too fast
• You can make baking powder by combining baking
  soda, cream of tartar and corn starch

10
Baking Powder

• Comes in two types
• Single Acting and Double acting
• Double Acting contains two acids-one that reacts
  with cold liquid and one that reacts with heat
• Most of the carbon dioxide is produced when
  heated in the oven
• Preferred in the US
• Single Acting as soon as liquid is added carbon
  dioxide starts to be released
• Rarely sold in US

11
Power of Baking Powder

• By Federal Law Baking Powder must yield 12g of
  carbon dioxide for every 100g of powder
• Most yield about 14
• Baking Powder must be a least 25 baking soda by
  volume
• Too much baking powder causes flour mixtures to
  stretch too far and break and collapse
• Too Little will make a compact product
• If not stored in a tight container it can absorb
  moisture and react too early

12
Producing CO2 w/Yeast

• Yeast microscopic organism that produces carbon
  dioxide through fermentation
• Fermentation biological reaction that slowly
  splits complex organic compounds into simpler
  substances
• Yeast converts sugar to ethyl alcohol and carbon
  dioxide
• The alcohol evaporates and carbon dioxide causes
  the product to rise
• The yeast is killed by the high baking
  temperatures, which stops fermentation

13
Making Leavened Products

• Batters and Doughs
• Batters contain more liquid than doughs
• Pour Batters made with equal ratio of flour to
  liquid (usually water). Range from thin to hard
  to pour.
• Pour batters are used to make waffles and
  pancakes
• Steam is the main leavening agent in pour batter
  used to make popovers and cream puffs

14
Drop Batters

• Muffins, quick bread loaves and some cookies
• Mix 2 parts flour to one part liquid
• Baking powder and steam are leavening agents in
  these recipes

15
Soft and Stiff Doughs

• Soft Dough
• Mixing three parts flour to one part liquid
• Need more mixing to develop gluten
• Yeast breads, baking powder biscuits and pizza
  crusts are made from soft doughs
• Stiff Dough
• Six to Eight times as much flour as liquid
• Drier consistency
• Pie crusts and some cookies

16
Yeast Products

• Yeast Bread is made from soft dough
• Yeast is sold in granular and compressed forms
• Pellet is stable at room temperature
• Compressed should be refrigerated or frozen
• Basic Ingredients include Flour, Liquid, Salt,
  Sugar, Fat and Eggs

17
Purpose of Ingredients

• Flour provides starch, proteins that form
  gluten, gives structure
• Liquid Usually water or Milk.
• Milk is often chosen because it adds ingredients
  and makes bread last longer. Steam from the
  liquid combines with the CO2 produced by the
  yeast helps the bread rise.
• Salt Adds Flavor. Prevents enzymes from breaking
  down proteins
• Sugar, Fat and Eggs Sugar helps crust brown and
  adds flavor. Eggs make the bread richer in
  texture and flavor

18
Quick Breads

• Need no time to rise. These products are made
  with a leavening agent other than yeast. Usually
  steam or COs that is produced by baking soda or
  baking powder
• Muffins, Coffee Cakes, popovers and biscuits are
  examples
• All contain flour, liquid and salt
• Proper mixing is important
• Over stirring or mixing overdevelops the gluten
  producing a tough product

19
Leavened Cakes

• Leavening used affects the cakes texture
• Traditional cakes such as sheet cakes, and
  layered cakes are shortened cakes
• Contain fats ad chemical leavening agents
• Air is added when fat and sugar are beaten
  together or if the recipe calls for eggs to be
  beaten separately
• Fat and eggs tenderize the batter so it expands
  easily

20
Pound Cakes/Unshortened Cakes

• Pound Cakes primarily leavened with air and
  steam
• Air is incorporated when batter is mixed
• Heat changes liquid into steam, the steam
  enlarges the air bubbles and causes the cake to
  rise
• Unshortened Cakes include Sponge, Chiffon and
  Angel food cakes
• Depends on the air beaten into an egg foam for
  leavening, Steam is also used
• Angel food cakes expand more due to the amount of
  egg whites used
• Eggs provide protein and contain water that
  converts to steam, creating a tall, light cake