Soft Vs Hard cookies --- Which do your prefer? 💁🏼 (Revised)

The Mysterious Chocolate Chip Cookies

                                                                                                                       Author: Hody, Sherby, Liv, Canny

Introduction

Most traditional chocolate chip cookie recipes start with some of the basic ingredients: butter and sugar (a mixture of white sugar and brown sugar). It is suggested that different proportion of different types of sugar will lead to different structure and texture of the cookies. Therefore, in this experiment, we are going to investigate the effect of the sugar in the cookies, like the spreading of the cookies, the rise of the cookies and the texture of the cookies.

Sugar is one of the vital ingredients of the cookies, the type of sugar we use can have a significant effect on the finished cookies. There are two main types of sugar: white sugar and brown sugar. They have some structural different.



Science behind the making of cookies

Sugar
Sucrose is the most important sugar in cookie making. It delivers sweetness, influences the structural and textural properties of cookies, and is presumed to incorporate air into the fat during cookie dough preparation. Furthermore, in cookies, sucrose decreases dough viscosity (Maache-Rezzoug et al., 1998). During baking, the undissolved sugar progressively dissolves and hence contributes to cookie spread (Hoseney, 1994). Other parameters that are influenced by the recipe's sugar (level) include cookie hardness, crispness, colour, and volume.


White sugar
Crystallised sucrose, a disaccharide which consists of a fructose and a glucose linked together. It is also mildly hygroscopic which can retain moisture in their structure, and relatively has a neutral pH.


Brown sugar
Mostly crystallised sucrose, contains a good amount of glucose and fructose, and trace minerals will present in it and give it flavour, and a slightly acidic pH. As it contains glucose and fructose, they are far more hygroscopic than sucrose, which means they have a higher ability to trap water in their structure relatively. So in this experiment, we will mainly focus this effect on the results of cookies.


Rise and spreading of cookies
Due to the air bubbles produced in the baking process. Baking soda is used as the raising agent for the cookies in this experiment. The baking soda and the sugar will have chemical reaction.

 Sodium Bicarbonate + Acid --> Carbon dioxide + Water + Salt

Brown sugar, which is slightly acidic, will react with the baking soda to create more bubbles that leaven the cookies, which is believed to raise the cookies higher than white sugar does. Therefore, it is expected to have a cakier and tall cookie when brown sugar is in used. As the rise of cookies and the spreading of cookies is relative, if the spreading is large, the cookie will become thinner thus less rising.

                           
Texture of cookies 
The structure of white sugar is more difficult to hold moisture compared to the ability to brown sugar. Hence it is expected that the white sugar-based cookies give up moisture more readily in the baking process, which ends up more crisp.




Hypothesis

Cookies made with...

• Brown sugar will rise higher when baking, the appearance will be thicker, and the texture will be softer. 

• White sugar will spread wider when baking, the appearance will be thinner, and the texture will be harder and crispier.

Sugar	White sugar	Brown sugar
Spreading of the cookie	More spread	Less spread
Rising of the cookie	Thinner	Taller
Browning of cookie	Less browning	More browning
Texture of the cookie	Crispier and Harder	Softer

Controlled Variables

• Brand, Type and Amount of all the ingredients expect Sugar
• Amount of Sugar added (80 g)
• Size of each dough balls before putting into the oven (1 tablespoon)
• Duration for Baking (10 mins)
• Temperature of the Oven (180°C)
• The ruler, knife and length of toothpicks used in each measurement
• The force used for inserting the toothpick and knife into the cookies (100g)

Independent Variable

• Types of Sugar (Brown VS White)

Dependent Variable

• Texture (Harder and Crispier VS Softer)
• Rising (Thinner VS Taller)
• Spreadability 

Ingredients

• Sugar                                       80g
• Unsalted butter                     20g
• All-purpose flour                   95g
• Chocolate chips                  50g
• Baking soda                     1/4 tsp
• Salt                                      1/2 tsp
• Vanilla extract                     1 tsp
• Eggs                                          0.5

Equipments

• Electric mixer
• Electronic balance
• Spatula 
• Bowls
• Ruler
• Knife
• Toothpicks

Method


1. Preheat oven to 180 degrees Celcius. 

2. In a large bowl, whisk together the flour and baking soda.

3. In a large bowl, beat the butter and sugar with electric mixer on medium 

    speed until light and fluffy for about 5 minutes. 

4. Add the salt, vanilla, and eggs. Beat until well mixed on low speed for about 1 

     minute.

5. Add flour mixture and mix until just combined on low speed. 

6. Stir in the chocolate chips.

7. Drop doughs (1 tablespoon each) on baking sheets lined with parchment        
    paper.

8. Bake the cookies for 10 minutes.

9. Remove from oven, and let cool on baking sheet 1 to 2 minutes.

10. Transfer to a wire rack, and let cool completely.

11. Compare for the result for the appearance and the texture of the cookies.




Measurements

Spreadability of the cookies
Measure the diameter of each cookie by using a ruler


Rising of the cookies
Measure the height of the cookie by using a ruler


Texture of the cookies
Test the hardness and softness of cookies by using the same force to insert a toothpick and knife into the cookies, mark down and measure the depth of the inserted parts of toothpick and knife.


Appearance of the cookies
See the browning of cookies by observation



Discussion

Why are we doing this experiment?

Because we all love eating cookies!! 😍  While we found that although cookies are all called cookies, some of them are soft (like those from Mrs Fields), while some of them are crispy and harder (like those store-bought cookies). Therefore, we would like to find out why they are different!


Reference

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