Science of Baking - Cookie Baking

I am not an active blogger. An active blogger is not just one who posts regularly. An active blogger is the one who is active in the blogging community. make friends on social media networks, visit other blogs, comment, post messages on facebook, tweet posts etc. My real life responsibilities do not let me spend a lot of time on these things, so I just create stuff, post about it and leave the rest to you all to find it and read. If you are interested that is. Since I am not an active blogger, I do not get much feedback from others either. Fair enough. But when I wrote 'Science of Baking - Cake Baking' post, the response was very positive. I thank you all for taking time to read and say nice words. That post's response encouraged me to write this post as well. I hope you all find it useful or amusing at least.

What is a Cookie?
Cookie can be a dessert or a snack that is small enough to be one per serving or two per serving. It can be puffy or crunchy. It could be a drop cookie, rolled cookie, shaped cookie or a bar cookie. Did you know most of the drop cookies can be baked as bar cookies? You just need to know what size pan to use. Rolled cookies can be converted as bar cookies too. Same is not true to convert drop cookie dough into something that can be rolled.

Ingredients of a cookie:
If you try to understand the science, you will see that you can convert any cookie recipe into a cake recipe and vice versa. Yes, I am not kidding. Basic ingredients in a cookie is the same as a cake - Flour, Sugar, fat like butter, oil, shortening or margarine, eggs or egg substitutes, leavening agents like baking soda, baking powder, salt, flavorings. When I say you can convert a cake recipe into a cookie recipe, leave out the liquid part, reduce the number of eggs, alter the amount of fat and leavening agent. You have a perfect drop cookie recipe. I will not go into details of the ingredients since I have already covered it in the Cake Baking post.

Mixing:
Most of the cookie recipes call for creaming butter with sugar unless it is a cookie recipe based on oil or melted butter. Usually the steps is to cream butter and sugar or sugars (when both brown sugar and white sugar are used), followed by beating the egg into the creamed mixture. You then add the dry ingredients and beat for few seconds, fold in the additions like nuts or chocolate chips.  Make sure you don't over mix than what is needed. Over mixing will also make the gluten in the flour to develop which can make the end product hard. Whenever you are dealing with oil or liquid fat, it is very important to fold the dry ingredients instead of beating with the electric mixer. This makes sure there is no gluten development.

How does the cookie baking work:
Cookie dough is almost all the time thick enough to be scooped. Thicker the batter, puffier the cookies. Or colder the dough, puffier the cookies. That is the reason for some of the cookie recipes calling for chilling the dough. Most of the cookies are baked for only 10 - 12 minutes at 350 or 375 F. I have come across very few recipes which call for baking them at lower temperatures. This applies particularly to short breads which do not have any leavening agents at all (traditional ones have just butter and sugar). Because of baking such small amounts of dough in mounds, it forms the crust fast and gets cooked pretty fast.



Best pan to use for cookie baking:
Always use shiny aluminum cookie sheets for baking. Line them with parchment paper to prevent them from sticking, over browning on the bottom. Remember that if a cookie baked directly on the cookie sheet takes 10 minutes to bake, it takes at least 12 minutes on the cookie sheet that is lined with parchment paper. If you bake the cookie on a non-stick baking sheet, make sure you check them 2 minutes early. Unless you are using a convection oven, always and always rotate the pan while baking cookies. Even if you are baking only one sheet. That ensures even baking of all the cookies. Make sure you space the dough as per the recipe instructions. Otherwise, when they spread, they will join each other and it won't be pretty.

General formula for a Cookie:
Remember there are tons of recipes which adhere to this and there are even more which do not. This does not work for low fat cookie recipes either.
Usually for every cup of flour, there will be 1/2 cup - 2/3 of sugar, 4 - 6 TBSP of fat, 2 TBSP of egg per cup of flour (1 egg for every 2 cups of flour) in most of the cookie recipes. Leavening agent will be around  1/4  tsp baking soda for every cup of flour. If the recipe calls for baking powder, it will be around 1 tsp per cup of flour. Remember that baking soda is much stronger than baking powder. Each tsp of baking powder has 1/4 tsp baking soda, 1/4 tsp cream of tartar and 1/2 tsp corn starch. Depending on if the recipe is for crunchier cookie or puffier, there could be some liquid present or it could have more number of eggs to facilitate spreading.

Please remember that it is just a guideline and there are too many recipes that do not stick to this rule. Particularly eggless cookies and vegan cookies have an entirely different way of working that is hard to generalize. You can look at various cookie recipes on this blog here.

Enjoy.