Cookies

Also known as Biscuits (UK, Canada)

What are Cookies?

Cookies are baked treats. A cookie is a small sweet, crispy or cake-like pastry most often made with flour, sugar, liquid and fat. They are characterized by:

• High sugar content
• High fat content
• Low moisture

Origin and varieties

The cookie’s  name is derived from the Dutch word koekje, meaning “little cake.” The earliest cookie dates as far back as 7th century A.D. in Persia, where sugar was first  cultivated. In England and the British colonies, cookies are also called biscuits. Germans call them Keks, or Plätzchen, and Spaniards call them galletas. In Italy, there are several forms of cookies, including amaretti and biscotti. The most popular cookie flavor in America is chocolate chip.

How are cookies produced?

There are three main stages to cookie dough production:

1. Creaming – The fat or shortening is creamed with the sugar to entrap air cells and create a fluffy texture. Other ingredients like salt, dry eggs, and baking powder are also added at this stage to improve homogenization of the dough.
2. Incorporation of liquids – The addition of liquids at this stage helps disperse and homogenize the dough, and aeration continues.
3. Incorporation of dry ingredients – The last stage of flour addition, or folding in of the flour, gently introduces the flour into the dough without destroying the air cells. Adding flour at the last stage also prevents a gluten matrix from forming, thereby producing a short bite for the cookie. This results in a short bite for the cookie.

Cookies are produced according to varied formula compositions, in many different shapes and sizes, and by various manufacturing procedures. The main components are flour, water, fat, sugar and chemical leavening.

Flour¹

Flour used for cookie production is around 8-10% protein and milled from soft red winter wheats with low water absorption capacity. This has a strong effect on the cookie spread and structure. Flour particle size and damaged starch also have effects on cookies. Flours with smaller particle size produce cookies with less spread, due to the increased presence of damaged starch. Damaged starch absorbs more water than intact starch, thus leaving less water available for the cookie to flow. High levels of damaged starch are detrimental to cookie quality.

Wheat flour of particle size greater than 150 μm is better for cookie production.¹ If there is a desire to limit cookie spread, as in the case of Marie biscuits or Oreo® cookies, hard wheat flours of medium-high protein may be used. In addition, if a tough structure is needed in rich cookie formulations, bakers may use chlorinated flour.

Water

Water absorption is the amount of water taken up by flour to achieve the desired consistency or optimal end result. Water absorption levels will vary from 50-54% in a cookie formula.²

Sweetener

Cookies are thought to consist of a continuous glassy sugar matrix with ungelatinized starch granules embedded within, together with an undeveloped gluten network with fat. Sweetener composition plays an important role in the softening properties of cookies.³ The sweetener level in cookie dough is 17-30% on a solid basis.³ Sweeteners regularly used in cookie production include sucrose, high fructose corn syrup, invert sugar or corn syrup.

The particle size of the sugar affects cookie spread as well. The smaller the crystals, the more rapidly the crystals dissolve, contributing to a larger aqueous phase and increasing spread.⁴

Cracking that occurs on the top surface of the cookie is referred to as cookie top grain. It is an important aspect of cookie quality. Good top grain (many surface cracks) results from recrystallization of sucrose at the cookie surface during baking.¹

Fat

Fat or shortening acts as a lubricant and contributes to the plasticity of the cookie dough. Its main function is as an aerating agent, entrapping air cells during mixing. These air cells act as nuclei for the chemical leaveners that produce the carbon dioxide during baking. Therefore, the creaming step during the making of cookie dough is crucial to the volume of the cookie and its texture.

Fat also prevents excessive development of the gluten proteins during mixing, making cookies less tough and resulting in a shorter bite. Fat imparts desirable eating qualities and contributes to texture and flavor of the product. It also influences dough machinability during processing.⁵

Fat or shortening is added, usually at 50% (chocolate chip cookie) to 80% (oatmeal raisin cookie) on a flour basis.

Chemical leavening⁶

Chemical leavening is the combination of sodium bicarbonate (baking soda) and acidic agents with water to generate carbon dioxide gas in controlled volumes and rates. Ammonium bicarbonate or potassium bicarbonate may be used instead of sodium bicarbonate.

For cookie baking, chemical leavening will be pre-blended with the flour and any other dry, minor ingredients. This blend is added to the cookie batter in the final stages of mixing. Chemical leavening will begin to react upon hydration; therefore, timing and the choice of leavening are key to proper cookie aeration and gas retention. The usage level for cookies is usually 0.5-1% of flour weight.

FDA Recommendation

The FDA suggests not eating raw cookie dough, as microorganism contamination in flour could make people sick.⁷ When making cookie dough for consumption, use heat-treated flour.

A typical commercial chocolate chip cookie formula (based on baker’s percent):

• Granulated sugar:  40%
• Brown sugar: 40%
• Corn syrup: 10%
• Shortening: 65%
• Salt:  1.5%
• Dry eggs: 5%
• Baking powder: 1%
• Water: 15%
• Vanilla:  2%
• Pastry flour: 100%
• Chocolate chips:  65%

1. Cream the sugars, corn syrup, shortening, salt, dry eggs, and baking powder at 1^st speed. Scrape, then increase to 2^nd speed for 3 minutes.
2. Mix the water and vanilla, and slowly add it in at 1^st speed. Scrape, and then mix at 2^nd speed for 2 minutes.
3. Mix the pastry flour and chocolate chips in a separate container and add it into the mixer. Mix at 1^st speed for 15 seconds; scrape down and mix at 2^nd speed for 15 seconds. Do not over-mix at this stage, or you will develop the gluten network and produce a tougher cookie.
4. Transfer cookie dough into depositor. Deposit cookies onto sheet pans with liners.
5. Bake in the oven at 350^oF for 13-15 min, or until cookies are golden brown on the bottom.
6. Remove the cookies from the oven and transfer onto a cooling shelf immediately; otherwise you will overbake the cookies, as they continue cooking on the pan.
7. Cool for 1 hr before packaging.
8. Cookies can be stored frozen for extended shelf life.
9. Frozen cookies can be thawed and served without reheating.

References

1. Sheweta B.,  Mudgil D.,Khatkar B.S. Effect of flour particle size and damaged starch on the quality of cookies. Journal of Food Science and Technology 51.7 (2012):1342-8.
2. Bakerpedia. Water Absorption | Baking Processes. https://bakerpedia.com/processes/water-absorption/. Accessed 25 July 2017.
3. Kulp K., Olewnik M., Lorenz K., Collins F. Starch functionality in cookie systems. Starch – Stӑrke 43.2 (1991):53-7.
4. Kiyoshi K., Toh M., Hagura Y. Effect of sugar composition on the water sorption and softening properties of cookie. Food Chemistry 145 (2014):772-6.
5. Jissy J., Leelavathi K. Effect of fat-type on cookie dough and cookie quality. Journal of Food Engineering 79.1 (2007):299-305.
6. Bakerpedia. Chemical Leavening | Baking Processes. https://bakerpedia.com/processes/chemical-leavening/. Accessed 24 July 2017.
7. US Food and Drug Administration. Consumer Updates – Raw dough’s a raw deal and could make you sick. US FDA Home Page. 28 June 2016. https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm508450.htm. Accessed 14 July 2017.