How The Cookie Crumbles

A rush of hot air, slightly singeing the delicate cilia lining of your nostrils; your eyes reflexively shut as you inhale: tantalising aroma of caramelising sugar, comforting buttery whiffs amidst a nostalgic embrace of vanilla… And just before you exhale, underlying notes of cinnamon invigorate your senses, tempting you to lean in closer – but not too close. Like a hug from the past, you are wrapped in the glorious scent of freshly-baked cookies. They rest on the counter to cool, and you notice that with each passing minute, a few more cookies seem to disappear magically into your stomach. Perplexing indeed.



Now, if you aren’t ravaging through your pantry in search of the aforementioned crumbly temptress, then I fear you are in dire need of a doctor’s visit. For who in their right mind does not love a good cookie?! Crisp golden exterior; chewy, molten centre. Or perhaps you prefer a good ol’ chunky munch, or a sensuous cakey texture. Whatever your preference, a cookie exists for everyone.

But how can so many cookie species exist? And how on earth does one perfect the art of cookie-baking to produce their ideal crumb? What sorcery lies behind our beloved cookie?!

The secret to the perfect cookie lies in science.




Cookie Science


“It’s one of the first lessons in culinary school: Baking is a science.”


Baking is a chemical art; chemistry in its most glorious form. Have you ever wondered why you suck at baking? You follow the steps to a T and yet, while your creation incubates behind the protective oven door – a punctual timer ticking obediently in the background – the revelation is far from desired.




Like all chemical reactions, the end product relies on a fragile balance of components; slight alterations in temperature, ratio, or timing, can result in something completely different. I learnt this the hard way, through my first batch of jam-drop cookies… T’was a fateful summer’s afternoon, and my insatiable need for chewy-topped, warm-centred, little circles of joy was overwhelming. As I perused the seemingly-innocent recipe slapped onto the side of a flour packet, my health-conscious parents’ words rang through my head, “never use white flour and always reduce the sugar and fat or find alternatives!”

I naively assumed that the product of my drastically reduced sugar and fat, whole-wheat “cookies” would somehow turn out delectably… Despite my father’s praise at creating such a ‘healthful’ alternative, I knew something was amiss. Where was that signature cookie scent? The moreish flavour and mouthfeel? – I had somehow managed to create giant air pockets in the centres of my cardboard-like cookies (which I admit was somewhat impressive). Truthfully speaking, I’d created no cookie, but rather, a ‘rock cake’ whose only moisture and flavour came from a smidgen of jam smeared above its protruding gas-filled innards.



We live and we learn, and I’d like to think that after numerous cookie-experiments, I have come a far way since then…

But enough about me, if you’re reading this, then I think it’s safe to assume that you’re probably familiar with the typical cookie anatomy, or at least have a vague idea from countless ‘taste-tests’:



It’s not enough just knowing what goes into a cookie to master its nuances and complexities. To really understand the enigma that is the ‘cookie’, we must delve a little deeper into what each of these components actually do behind closed doors…


In the Bowl

We all want to be a ‘tough cookie’, but I’m sure I can speak for all us in saying that we certainly don’t want to eat a tough cookie. During the mixing process of combining wet to dry, proteins in wheat flour (glutenin and gliadin, if you really want to know) activate upon moisture contact, causing a tacky dough ball to form. As you work the dough, by mixing or kneading, gluten strands develop, forming a network which can make your cookie tough if you over-do it!



In the Oven

The oven is where all the exciting stuff happens:

  1. Fats melt and distribute, causing the cookie to spread.
  2. Raising agents are activated forming gasses which expand and raise the cookies.
  3. Sugar dissolves
  4. Proteins denature and bind, forming the cookies ‘skeleton’ so they can retain their shape
  5. Moisture evaporates
  6. Starch gelatinises as the flour absorbs moisture in the presence of heat which contributes to the cookie’s tender texture.
  7. Caramelization and Maillard Reaction (browning) of sugars and proteins occur on the crust producing that tantalizing aroma and giving the cookie a deeper flavour and delightfully crisp, bronze, exterior. If your oven is under 160 degrees Celsius, these processes can’t occur and the resultant cookie will be far blander.



On the Cooling Rack

If your cookies survive the arduous journey from oven to cooling rack, then you can expect them to undergo even more changes. As the cookie cools, gluten and egg proteins set, caramelization completes as the sugars crystallise, and, since the humidity of the room is lower than the cookie, moisture is drawn out from the cookie, resulting in a firmer cookie. But, over-do the wait time and they’ll do the opposite by absorbing environmental moisture, making them unfavourably soft – so be sure to move them into an airtight container as soon as they’re chill!



Engineering Your Ideal Cookie

As I always tell my friends in regards to their choice of male companions – never settle. Cookies are no exception. Don’t just accept what’s available if they fall short of your expectations, make your dreams a reality by creating your own! On my quest to developing the perfect chewy, molten centre, crisp-top cookie, I’ve filtered through countless experiments conducted by like-minded bakers in their pursuit of perfection.

 “If you know the ingredient and how it behaves, you have a better chance of success,”

 – Laurie Sargent, Columbus Culinary Institute’s lead pastry instructor.





Rule 1: Master The Ingredients

 The first step is, of course, to understand what you’re working with.



  • Flour: Wholemeal, white, plain, bread flour, pastry flour – what’s the diff? Seeing as flour provides the bulk of the cookie, it’s not something you want to get wrong. Pastry and cake flours are lower in gluten, resulting in a finer short-bready crumb. Contrarily, bread flour, higher in gluten, will produce a chewier cookie. If you wanna opt for the healthier option of wholemeal flour, know that all the fibrous gritty bits cut through the gluten formation, giving you a crumblier consistency. Good ol’ ‘All Purpose’ plain flour is the most tried and trusted option.
  • Fat: Don’t make the same mistake as young Lydia; fat really is an essential cookie-component, giving cookies their tender moreish texture. Whilst some people opt for oil, margarine, or shortening, butter is still the favoured fat option. Recipes might call for chilled butter, room-temperature, or melted butter – how does this affect the cookie? As Liz Roth-Johnson, molecular biologist and manager of the University of California’s Science and Food blog, explains: melted butter -> wetter dough which spreads faster -> flatter wider cookie. Plus, since there’s less water in melted butter to evaporate into gas, more and smaller holes are created in the cookie, making for a chewier texture. Contrarily, the colder the butter, the larger the air holes, and the cakier the consistency.
  • Sugar: Just like flour, there seems to be an unnecessarily wide range of sugar-types. Recipes will commonly call for caster, granulated, or brown sugar. Brown sugar, being less refined, gives a deeper flavour and colour, and as it is slightly acidic, reacts more with the soda to increase the height and reduce the spread of the cookie; the cookies retain more moisture and are therefore cakier in texture. Refined white sugar doesn’t have this leavening effect, meaning the cookies will spread more and end up crispier as they don’t retain as much moisture.
  • Raising Agents (leavening agents): Baking soda or baking powder? What’s the diff? – This is probably one of the most commonly-asked baking questions. Soda reacts with liquid, acid and heat to release carbon dioxide gas which makes the mixture rise. Baking powder has added acid already present which initiates the leavening reaction earlier and to a greater extent, creating a fluffier cakier cookie.  A strange bitter, fuzzy taste, means you’ve been too heavy-handed with the raising agents.

Amazing. I know.



Rule 2: Know The Environment

To master your art, you must first master your environment.



Manage The Time

  • Use your nose: I must admit, time management is not my forte. When it comes to baking however, let your nose guide you. Rather than setting a strict timer to test the readiness of your cookie, aromatic compounds released during the Maillard reaction will signal your senses to prepare for devouring; so, when the bells ring in your nostrils, it’s probably time.
  • Let your dough rest: This is a hard one. Usually when I decide to make cookies I want to eat them instantly… Not wait a good 24hrs before popping them in to bake. If you can anticipate your cookie-cravings beforehand, then it might be a good chance to test this out. While the dough sleeps in its cool chambers, starches and proteins have a head-start at breaking down, which means that by the time their reach their tanning beds (i.e. oven) more flavour compounds are ready to be acted upon to heighten texture, flavour and colour.


Tamper The Temperature

  •  The dough: Chilled dough = more compact cookies that don’t spread as much. Warm dough = greater spread.
  •  The oven: The lower the oven temperature, the more evenly the cookie bakes throughout and the more time it has to spread out. For a thicker cookie with a crisp brown exterior and soft centre, amp up that heat!



I didn’t realise how dangerous unravelling the secret of cookie-making would be when I first decided to pen this article… In the past two days I’ve managed to bake and consume three batches of vegan chocolate chip cookies. While they were entirely edible and not unpleasant, they didn’t quite meet my expectations; thus, the baking shall continue – stomach ache aside. If you need me, you’ll find me in the kitchen covered in flour.




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