CONCEPT 48: SUGAR CHANGES TEXTURE (AND SWEETNESS) Flashcards
Sweetners come in many forms. Describe some.
Crystalline white table sugar, deep bronze brown sugar, thick, oozy molasses, and the lighter, golden honey.
Sugar, like glucose and fructose, can be a single molecule made of what?
Cardon, hydrogen and oxygen.
What two molecules is sucrose made of?
Glucose and fructose tied together with chemical bonds.
Table sugar consists of pure what?
Sucrose
Is sucrose abundant in many plants?
Yes, especially fruits.
Unlike in fruits, some plants, like potatoes, convert the sucrose they form into what?
They use photosynthesis and turn it into starch.
What does the ability of some vegetables becoming sweeter in the fridge say about turning their sucrose into starch?
The process is reversible.
What is table sugar produced from?
Sugar cane or sugar beets.
Is sucrose water soluble? Explain.
Yes, it’s highly water soluble; when dissolved, the sucrose molecules organized within each crystal disperse into water.
Does sugar melt? Explain.
No, it decomposes when brought to temperatures between 320 and 367 degrees Fahrenheit.
How does sugar affect texture in cookies and cakes?
Because of the nature of hydrogen and oxygen atoms in both water and sugar, they are electrostatically attracted to each other. When water and sugar are combined, they link together and form hydrogen bonds. It takes a fair amount of heat to break these bonds and, as a result, table sugar will hold on to moisture in food. Because of this tendency, sugar can slow the evaporation of moisture from cookies and cakes as they bake.
Is sugar hygroscopic? What is this?
Sucrose is hygroscopic, which means it has an affinity for water.
What happens when sucrose is heated along with some acid?
It breaks down into two simple sugars, glucose and fructose. When this happens, the result is called an invert sugar.
Why are invert sugars always viscous liquids?
Fructose does not easily crystalize in the presence of glucose.
Is invert sugar hygroscopic? Explain.
It’s especially hygroscopic, pulling water from wherever it can be found, the best source being the air.
Why is brown sugar the Test Kitchen’s choice when baking chewy cookies?
Brown sugar has more invert sugar than granulated sugar and continues to pull in moisture even after cookies have been baked, thus keeping them chewy as they cool.
How do sugar affect the texture of frozen desserts?
When making frozen desserts, sugar is usually heated with a liquid (water, cream, fruit juice) so that it dissolves. When dissolved, sugar lowers the freezing point of water. Because this mixture freezes at a lower temp, it is able to become far colder than 32ºF before beginning to form ice crystals while being made into ice cream. This means that when the ice crystals do form they form very rapidly - and stay very small. And tiny ice crystals translate into ice creams, sherbets, and sorbets that we perceive as smooth and creamy, not icy and grainy.
TEST KITCHEN?: CHOCOLATE CHUNK OATMEAL COOKIES MADE WITH BROWN AND GRANULATED SUGAR.
The brown sugar cookies had serious chew and the flexibility to conform to the curvature of a rolling pin. Cookies made with granulated sugar quickly snapped when bent.
Why do sweeteners like brown sugar make chewier cookies than granulated?
Sweeteners that contain invert sugar help to retard the crystallization of sucrose, therefore holding more moisture than white sugar.
Name 5 other factors, besides sugar, that create chewy cookies.
First, don’t be afraid of butter; melted butter encourages the formation of gluten when flour is added to the batter. Second, use a generous amount of dough for each cookie; it’s hard to keep small cookies chewy - at least 2 tablespoons if not more. Third, don’t over bake. Fourth, Take cookies out of the oven when set around the edges but look a bit underdone in the center; they will continue to firm up on the baking sheet. Last, cookies become less chewy over time; store them in an airtight container.
Why shouldn’t you use a nonstick pan for browning butter?
The dark coating makes it difficult to gauge when the butters sufficiently browned.
Does the brown sugars freshness matter in baking cookies?
Yes, hardened brown sugar will make cookies too dry.
How do you tell when dark colored cookies are finished?
Gently press halfway between the edge and center of the cookie. When it’s done, it will form an indentation with slight resistance.
Browning the butter creates flavors such as what?
Butterscotch and toffee.
What happened to sugar cookies when butter was creamed?
It created cake, tender cookies.
What happened when the butter was cut into the flour for sugar cookies?
It produced crumbly cookies.
What did test kitchen do to their butter for chewy sugar cookies?
Melted it.
What helps boost the nutty flavor in cookies without adding more brown sugar?
Vanilla
What tends to make cookies cakey? Explain.
Egg white cause cookies to puff and dry out; test kitchen threw out some of their whites.