Cookie chemistry

What makes a chocolate chip cookie chewy? Or crisp, or crunchy?

Cookie chemistry.

The interaction between sugar and fat and flour, baking time and temperature – plus a large measure of experimentation done right in your own kitchen – is how to nail your favorite chocolate chip cookie texture.

Let me tell you up front: I'm devoted to simplicity in food prep, and that includes baking. I don't use a cookie cutter, braid bread dough (aside from a basic 3-strand), or decorate cakes.

I put my heart and soul and brain into everything I bake – but I also put those three entities into a zillion other things important to me: like family, friends, counseling women with health issues, and volunteering at various non-profits.

So I'm not fond of trying 87 different takes on a recipe to get it exactly right.

First, I see that as a waste of time; if you can get 95% of the way there in the first three tries, you're good.

And second, having been developing recipes for King Arthur Flour for over 25 years, I know that what comes out of my home kitchen won't be exactly what comes out of yours – even when you follow the recipe exactly as written. Your oven, pans, ingredients, and even your micro-climate and the weather affect what you bake.

So here's the deal: my goal with this post is to show you how to take a basic chocolate chip cookie recipe and give it the texture you prefer: light and crunchy; thin and crisp; or soft and chewy.

More words than you could shake a spatula at have been written about "the perfect chocolate chip cookie." But what is that elusive being, anyway?

Plain and simple, the perfect chocolate chip cookie is the one you love best. So we're going to start with my favorite chocolate chip cookie recipe and, with a few simple tweaks, give you options for potentially turning it into YOUR favorite chocolate chip cookie recipe – no matter which camp your textural preference falls in: crunchy, crisp, or chewy.

Here's your beginning formula. If your favorite cookie is one that's crisp around the edges and softer in the center, stop right here: this is the recipe for you.

2/3 cup light brown sugar, firmly packed
2/3 cup granulated sugar
1/2 cup unsalted butter, right from the fridge, or at room temperature
1/2 cup vegetable shortening
3/4 teaspoon salt
2 teaspoons vanilla extract
1/4 teaspoon almond extract, optional
1 teaspoon vinegar, cider or white
1 teaspoon baking soda
1 large egg
2 cups (8 1/2 ounces) King Arthur Unbleached All-Purpose Flour
2 cups semisweet chocolate chips

Note: For complete directions, see the recipe: Chocolate Chip Cookies. I'm providing you with just the ingredients and some suggested baking temperatures/times here. 

How to make crunchy chocolate chip cookies.

1. Substitute 2/3 cup granulated sugar for the brown sugar.

2. Substitute 1/2 cup vegetable shortening for the butter.

3. Bake the cookies for 23 minutes in a preheated 325°F oven.

Cookie chemistry: Crunchiness in a cookie depends on a good balance of fat and dryness. Butter contributes milk solids and water to a cookie, both of which soften it. Brown sugar contributes molasses – again, a softener.

Using lower-moisture sugar (granulated) and fat (vegetable shortening), plus a longer, slower bake than normal, produces light, crunchy cookies.

That said, using a combination of butter and vegetable shortening (as in the original recipe), or even using all butter, will make an acceptably crunchy chocolate chip cookie. It won't be AS crunchy as an all-shortening cookie; but for those who eschew vegetable shortening, it's an option.

How to make crisp chocolate chip cookies.

1. Substitute 2/3 cup granulated sugar for the brown sugar.

2. Substitute 1/2 cup butter for the vegetable shortening.

3. Bake the cookies for 30 minutes in a 325°F oven.

Cookie chemistry: The difference between a crunchy and crisp cookie is thickness; we perceive thicker cookies as crunchy, thinner cookies as crisp.

The melting temperature of butter is lower than that of shortening. As they bake, butter-based cookies start to spread before their structure is set; while those made with shortening set before the shortening reaches its melting point.

The result? In this recipe, cookies made with butter (above, left) are wider, thinner, and crispier than those based on shortening (above, right).

In addition, baking these thin cookies several minutes longer than their shortening-based counterparts transforms their innate crunchiness into crispiness.

How to make soft/chewy chocolate chip cookies.

1. Substitute 1 cup brown sugar for the 2/3 cup brown sugar and 2/3 cup granulated sugar.

2. Substitute 1/2 cup butter for the 1/2 cup vegetable shortening

3. Bake the cookies for 14 minutes in a preheated 325°F oven.

Cookie chemistry: We're taking a 180° turn from our crunchy cookies, substituting higher-moisture brown sugar and butter for their lower-moisture counterparts: granulated sugar and vegetable shortening. That, plus a shortened baking time, yields a cookie that's soft and chewy all the way through.

You'll notice these cookies use less sugar than the original recipe, too. Why is that?

Because the less sugar you use, the less cookies will spread. Above is a mistake I made along the way: one batch of cookies I made had 50% less sugar than it should have. See the difference in spread? (Actually, I liked this 50% less sugar cookie; it tasted plenty sweet, and its butter flavor was more apparent).

Considering I was using all butter (for its extra moistness) in my soft/chewy cookies, I didn't want to use the full ration of sugar as well, fearing the cookies would spread too much.

Some sources call for using bread flour to yield a chewier cookie. I wanted to believe in this, I really did, but the three tests I did showed no difference in chewiness between cookies made with King Arthur Unbleached Bread Flour, and those made with King Arthur Unbleached All-Purpose Flour.

Corn syrup is also recommended by some for extra-chewy cookies. And while I tried adding 2 tablespoons corn syrup to the dough along with the substitutions listed above, I didn't like the result: somewhat glossy, unattractive cookies that had no more chew than their non-corn syrup brethren.

My co-blogger, Susan Reid, says corn syrup is the only way to make "bendy" cookies – but I'll leave that for a future post.

I baked a LOT of chocolate chip cookies over the course of several days in putting together this post. Let me share some additional takeaways with you:

• The chips ratio: My favorite ratio of chocolate chips to cookie is 1 cup chips for every cup of flour in the recipe. This yields a cookie with a generous amount of chips, but not one that seems more gooey chocolate than crunchy cookie.

• Chill out: I discovered awhile ago that letting cookie dough chill for 30 minutes before baking improves cookies' flavor and helps control their spread. I also know that a fully heated oven is critical to cookie success. So make your cookie dough; put it into the fridge; then turn on the oven. Thirty minutes later, your dough will be chilled and your oven fully preheated.

And while we're on the subject – use an in-oven thermometer. The preheating times on ovens are notoriously inaccurate. Only an in-oven thermometer will tell you, for sure, whether your oven's up to temperature and ready to bake.

• Bake a test batch: The perception of crunchy vs. crisp vs. chewy is due somewhat to each person's own personal perception. In addition, all ovens bake slightly differently.

The baking times I give here work for my oven, and yield cookies that I taste as crunchy, crisp, or chewy. To nail down your own baking times, bake just 3 or 4 cookies to start. Let them cool sufficiently for you to see if they're the texture you're after.

Yes, this seems wasteful, letting your hot oven sit empty while cookies are cooling enough to assess their texture. But how much more wasteful is it to make an entire batch of cookies and then, 20 minutes after they're out of the oven, you decide they're not the texture you were looking for?

• Parchment makes a difference: All of my tests were done using parchment-lined, light-colored aluminum baking sheets (including the disastrous first take on chewy cookies pictured above).

Cookies baked on parchment won't spread as much; and their bottoms won't brown (or potentially burn) as quickly. For the complete results of our parchment/no parchment cookie baking tests, see our post, the secret to perfectly browned cookies.

We've arrived at the end of our chocolate chip cookie journey. And I can hear many of you saying, "Yes, but my chocolate chip cookie recipe uses butter and brown sugar and makes the perfect crunchy chocolate chip cookie!"

I have no doubt you can make crisp cookies with butter and brown sugar, and soft cookies with vegetable shortening and white sugar. If you already have your own "perfect" chocolate chip cookie recipe – stick with it! Like so many good things in life, there's more than one way to skin a cat – or bake a chocolate chip cookie.