Culinary+Chemistry

= = = = = = = The Role Of Chemistry In The Kitchen =

toc

The Process of Making Bread
The art of making bread is a time consuming and often labor intensive process, however when done correctly it is the result of a perfect reaction of correct measurements and prosperous yeast so that it can rise to the occasion of any meal or snack. First ingredients must be gathered and measured specifically to the directions so that no imbalance occurs. //[|Basic Bread Recipe]// Ingredients Needed: -1 cup of luke warm water (95-105 degrees farenheight) -3 1/2 cups of flour -2 teaspoons of salt -1 teaspoon of sugar -1 tablespoon of extra virgin olive oil -1 tablespoon of fresh yeast In a small bowl, using ones index finger, mix 3 tablespoons of the luke warm water with the yeast and sugar, and leave the mixture in a warm place to set for 10 minutes. In a separate bowl, sift in the flour and salt. Then mix in the wet ingredients, olive oil, water, and yeast-sugar mixture. Once mostly formed, knead the dough with a bit of extra flower on a board and your hands. Place the dough into a slightly oiled bowl and cover it with a damp towel, then place the bowl in a warm location for the dough to rise for about 2-4 hours. After the dough has risen take the towel off of the bowl and (gently) punch down the dough and carefully knead it into a pre-greased baking pan. Place the dough into an oven preheated at 400 degrees farenheight for 30-35 minutes. In order to check if the bread is done, it should sound hallow when tapped on the base.

 **Why Be Specific?** Certain steps within the process of making bread may seem unnecessary but are often useful once having looked at the chemistry behind the ingredients. One of the most important ingredients is yeast, because yeast is breads natural leavener. The organism known as yeast needs warmth and moisture to survive, but it also needs other sources of stimulants such as sugar or flour, in order to grow. In the case of bread making, the initial growth begins when mixing the sugar and yeast and water, because without the water the two "dry" ingredients would not react with each other. However, the temperature of the water is very important with the contact with the yeast. If the water is too hot (130+ degrees F ) than the yeast will die, and if the water is too cold than the yeast will remain stagnant and not be able to grow; the ideal temperature is a luke warm water between 95 to 105 degrees farenheight. The act of covering the rising dough with a [|damp towel] and placing it in a warm location is solely to enhance the yeast and allow it to be within an environment so that it can grow. Because yeast needs a moist and warm place to produce its gas bubbles, the towel and location provide an ideal growth situation for the yeast so that it can produce enough carbon dioxide to rise. Punching down the risen dough is a method used to spread out the gas bubbles within the dough so that the bread cooks evenly and does not crumble. Using a hot, preheated oven kills yeast quickly once the dough is placed in to bake; this helps prevent over rising of the dough and a delicious, crispy crust.

=The Chemistry Behind the Loaf = The process of making dough includes not only the mixing of the ingredients, but the rising process performed by the yeast. Yeast. Yeast is a living organism - a fungus to be exact. Like all other living organisms, it needs food to function - in this case sugar. Yeast "digests" the sugars, and performs a chemical reaction of fermentation. The reaction is as follows; C6H12O6 →2C2H5OH + 2CO2 The sugar (C6H12O6) splits off into alcohol(2C2H5OH) and carbon dioxide(2CO2). The carbon dioxide forms the bubbles in the dough that lighten the texture of the finished product. The alcohol is simply evaporated off during baking, and has no significant effect in the baking process. After the dough has been mixed and kneaded, it is let sit to rise. This is where the reaction takes place. The carbon dioxide released during the fermentation process creates many bubbles throughout the dough, causing it to "rise".

Calculations In Enthalpy
When the dough is rising, it feels warm. This is because the reaction taking place is exothermic. To calculate the change in enthalpy, we use Hess's law; Now we plug in the following data accordingly;


 * Compound || Heat of Formation (kj/mol) ||
 * C6H12O6 || -1271 ||
 * C2H5OH || -393.5 ||
 * CO2 || -277.0 ||

ΔHrxn = ((2(-393.5))+(2(-277.0))) - (-1271) ΔHrxn = (-787.0 + -554.0) - (-1271) ΔHrxn = (-1341) - (-1271) ΔHrxn = -70 kj

Therefore, this reaction loses energy, emitting it into the environment; an exothermic reaction warming the bread.

Glucose;



media type="custom" key="6313943"

=A Scientific Culinary Experience: [|Alton Brown, Good Eats] = media type="custom" key="6280679"

=__The Daily Bread__ = The process of making and eating bread is a tradition and custom that has existed long before our generation of people. Even back in ancient Greece and Rome, bread was baked, purchased, traded, and consumed by many and understood to be a valuable piece of scientific knowledge to prepare fully rising bread. Now it is still a significant piece of our economy and our process of chemical exploration, such as explaining the growth and effect of yeast when paired with water of different temperatures and ingredients such as sugar, flour, and salt. Although, the most significant par t of bread is the yeast, and yeast today serves as the base for many forms of carbohydrate energy consumption. Without its yeast, we would be consuming crackers and soda bread, because chemically baking soda and baking powder do not allow for the same chemical reaction and production of carbon dioxide gas bubbles for dough rising as yeast does. Bread being the all time "comfort food" (Alton Brown, Food Network) is used and needed in everyday life; but without yeast based breads, there would not be an appropriate chemical reaction to produce such a heart warming piece of food produced from the kitchen.

=__Works Cited__= http://www.chemistrydaily.com/chemistry/Bread http://www.helium.com/items/410397-explaining-the-chemistry-of-bread-making http://www.preparedpantry.com/howyeastworks.aspx Basic Recipe: http://www.foodnetwork.com/recipes/alton-brown/very-basic-bread-recipe/index.html l media type="custom" key="6297935" align="center"