The Chemistry of Baking Cookies

The Chemistry of Baking Cookies Baking cookies seems simple, especially if you cook pre-made cookie dough, but its really a set of chemical reactions. If your cookies never turn out perfect, understanding their chemistry may help improve your technique. Follow this classic chocolate chip cookie recipe and learn about the ingredients and the reactions that occur throughout the mixing and baking process. Chocolate Chip Cookie Recipe 3/4 cup granulated sugar (sucrose, C12H22O11)3/4 cup brown sugar (caramelized sucrose)1 cup unsalted butter (a fat)1 large egg (consists of water, protein, fat, emulsifier, and albumin)1 teaspoon vanilla extract (for flavor)2-1/4 cups all-purpose flour (contains gluten)1 teaspoon baking soda (sodium bicarbonate,  NaHCO3, which is a weak base)1/2 teaspoon salt (NaCl)2 cups semi-sweet chocolate chips Youll get the best results if you use room temperature eggs and butter. This helps the ingredients mix into the recipe more evenly and means your cookie dough will be room temperature and not cool when you put the cookies in the oven. The fat in the recipe affects the texture of the cookies and browns them, which influences flavor as well as color. Substituting a different fat in place of butter affects the flavor of the cookies and also the texture since other fats (lard, vegetable oil, margarine, etc.) have a different melting point from butter. If you use salted butter, its usually best to reduce the amount of added salt.Preheat oven to 375 degrees Fahrenheit. Its important to preheat the oven because if you put the cookies in the oven and the temperature is too low, the dough can spread rather than firm up. This affects the thickness of the cookie, its texture, and how evenly it browns.Mix together the sugar, brown sugar, butter, vanilla, and eggs. Mostly, this is to blend the in gredients so the composition of the cookies will be uniform. For the most part, no chemical reaction occurs at this point. Mixing the sugars with the eggs dissolves some of the sugar in the water from the eggs, so the crystals wont be as large in the cookies. Brown sugar adds caramelized sugar flavor to the cookies. While it doesnt matter what color of eggs you use (white or brown), the size matters, just like measuring all of the other ingredients! If you substitute an egg from a different bird than a chicken, the recipe will work, but the flavor will be different. You dont want to over-mix the ingredients because beating eggs for too long affects the protein molecules in the egg white. Real vanilla and imitation vanilla (vanillin) contain the same flavor molecule, but real vanilla extract has a more complex flavor because of other molecules from the plant. Mix in the flour (a little at a time), baking soda, and salt. You can sift the ingredients together to make sure they are evenly distributed, but sprinkling the salt and baking soda onto the mixture works too. The flour contains gluten, the protein that holds the cookies together, makes them a bit chewy and gives them their substance. Cake flour, bread flour, and self-rising flour could be substituted for all-purpose flour in a pinch, but arent ideal. The cake flour might produce fragile cookies with a finer crumb; the bread flour contains more gluten and could make the cookies tough or too chewy, and the self-rising flour already contains leavening agents that would make the cookies rise.  The baking soda is the ingredient that makes cookies rise. The salt is a flavoring, but also controls the rising of the cookies.Stir in the chocolate chips. This last to ensure the other ingredients are properly mixed and to avoid smashing the chips. The chocolate chips are flavoring. Dont like semi-sweet? Switch it out! Drop rounded teaspoons of the dough about two inches apart on an ungreased cookie sheet. The size of the cookies matters! If you make the cookies too big or put them too close together, the interior of the cookie isnt dont by the time the bottom and edges brown. If the cookies are too small, they may not brown enough by the time the middle is done, giving you rock-hard cookies. Theres no need to grease the cookie sheet. While a light spritz of non-stick spray might not hurt, greasing the pan  adds fat to the cookies and affects how they brown and their texture.Bake the cookies 8 to 10 minutes or until they are light golden brown. Which rack you put the cookies on depends on your oven. Usually, the center rack is fine, but if your cookies tend to get too dark on the bottom, try moving them up one rack. The heating element in a conventional oven is on the bottom. The Baking Process If the ingredients are high quality, measured carefully, and mixed as they should be, chemical magic happens in the oven to make great cookies. Heating sodium bicarbonate causes it to decompose into water and carbon dioxide: 2NaHCO3 → Na2CO3 H2O CO2 Carbon dioxide gas and water vapor form the bubbles which make cookies rise. Rising doesnt just make cookies taller. It also opens up space to keep the cookie from becoming too dense. Salt slows down the decomposition of baking soda, so the bubbles dont get too big. This could lead to weak cookies or to cookies that fall flat when they come out of the oven. The heat works on the butter, egg yolk, and flour to change the shape of the molecules. The gluten in the flour forms a polymer mesh that works with the albumin protein from the egg white and the emulsifier lecithin from the egg yolk to form the dough and support the bubbles. Heat breaks the sucrose into the simple sugars glucose and fructose, giving each cookie a shiny, light brown crust. When you take the cookies out of the oven, the hot water gases in the cookie contract. The chemical changes that occurred during baking help the cookie keep its shape. This is why undercooked cookies (or other baked goods) fall in the center. After Baking If the cookies arent devoured immediately, the chemistry doesnt end with baking. The humidity of the surroundings affects cookies after they have cooled. If the air is very dry, moisture from the cookies escapes, making them hard. In a humid environment, cookies can absorb water vapor, making them soft. After cookies have completely cooled, they can be placed into a cookie jar or other container to keep them fresh and delicious.

The French Expression VoilÃÂ

The French Expression Voil Pronunciation: [vwa la] Register: normal Even though voil is just one word, it has so many possible meanings- most of which require multiple words in the English equivalents- that weve decided to treat it as an expression. The first thing to know about voil is that its spelled voil. Please note that the grave accent on the a is obligatory. (See common misspellings at the end of this article.) Secondly, voil, which is a contraction of vois l (literally, see there), has varied uses and meanings, which are hard to define precisely, so weve provided numerous examples to help make the distinctions clear. Here, There Voil can be a presentative which introduces a visible noun or group of nouns and can mean any of the following: here is, here are, there is, there are. Technically, voil only refers to things that are farther away (there is/are), while voici is used for close things (here is/are), but in reality voil tends to be used for all of the above, except when a distinction between two objects is required.   Ã‚  Voil la voiture que je veux acheter.   Ã‚  Ã‚  Here / There is the car I want to buy.   Ã‚  Me voil !   Ã‚  Ã‚  Here I am!   Ã‚  Le voil !   Ã‚  Ã‚  Here it / he is! There it / he is!   Ã‚  Voici mon livre et voil le tien.   Ã‚  Ã‚  Heres my book and theres yours. This, That When followed by an interrogative adverb or indefinite relative pronoun, voil means this/that is:   Ã‚  Voil oà ¹ il habite maintenant.   Ã‚  Ã‚  This is where he lives now.   Ã‚  Voil pourquoi je suis parti.   Ã‚  Ã‚  Thats why I left / That is the reason (why) I left.   Ã‚  Voil ce que nous devons faire.   Ã‚  Ã‚  This is what we have to do.   Ã‚  Voil ce quils mont dit.   Ã‚  Ã‚  Thats what they told me. Filler Voil is commonly used as a sort of summing up expression at the end of a statement. This is usually just a filler and doesnt have a simple English equivalent. In some cases, you could say you know, OK, or there you have it, but in general we just leave it out of the English translation.   Ã‚  Nous avons dà ©cidà © dacheter une nouvelle voiture et de donner lancienne notre fils, voil.   Ã‚  Ã‚  We decided to buy a new car and give the old one to our son.   Ã‚  On va commencer avec ma prà ©sentation, suivie dune visite du jardin et puis le dà ©jeuner, voil.   Ã‚  Ã‚  Were going to start with my presentation, followed by a visit to the garden and then lunch. How Long Voil can be an informal replacement for depuis or il y a when talking about how long something has been going on or how long ago something happened.   Ã‚  Voil 20 minutes que je suis ici.   Ã‚  Ã‚  Ive been here for 20 minutes.   Ã‚  Nous avons mangà © voil trois heures.   Ã‚  Ã‚  We ate three hours ago. That's Right Voil can be used to agree with what someone just said, along the lines of thats right or thats it exactly. (Synonym: en effet)   Ã‚  - Alors, si jai bien compris, vous voulez acheter sept cartes postales mais seulement quatre timbres.   Ã‚  Ã‚  - Voil.   Ã‚  - So if Ive understood correctly, you want to buy seven postcards but only four stamps.   Ã‚  Ã‚  - Thats right. Now You've Done It Et voil is commonly used, especially when talking to children, after youve warned them about something and they do it anyway, causing the very problem you tried to prevent. Not quite as mocking as I told you so, but along those lines: I warned you, you should have listened, etc.   Ã‚  Ã‚  Non, arrà ªte, cest trop lourd pour toi, tu vas le faire tomber... et voil.   Ã‚  Ã‚  No, stop, thats too heavy for you, youre going to drop it... and you did / I warned you. Spelling Notes Voil is sometimes used in English, and for this reason, its often written voila. This is acceptable in English, which tends to lose accents on words borrowed from other languages, but its not acceptable in French. There are several other common misspellings: Voil has the wrong accent. The only letter that ever has an acute accent in French is e, as in à ©tà © (summer).Viola is a word, though not a French one: a viola is a musical instrument slightly larger than a violin; the French translation is alto.Vwala is an Anglicized spelling of voil.Walla? Not even close. Please, use voil.