Everybody that has cooked with me before knows that I like to lean on my Food Engineering background to explain why things work the way they do in the kitchen. It’s fun to understand things from the inside out and also, in my opinion, when we make sense of something it is easier to remember it in the future.

One of the treats that I look forward to during the holidays are butter (or sugar) cookies. I like them snappy, light, and not too sugary, so the glaze really stands out. They are easy to make and are a real success in any party I bring them. They also keep well for days in an air tight container. So, today I wanted to share three basic tips and their scientific explanation to make delicious sugar cookies.

1. Cream The Butter

This might be the most important step when making any kind of cookies, and there is a lot of science here. The science behind creaming butter and sugar is all about creating a light, airy structure in your cookies.

We start with a room temperature, soft but not melted butter. Then we vigorously beat the butter and sugar together, until we cannot feel the granules of sugar and the mixture has gotten slightly lighter in color and texture. What happened there?

Physically, we are performing a process called mechanical leavening. As we beat the butter, we're folding it over and over, creating tiny pockets of air, trapped by the butter fat. The sugar crystals act like miniature shovels, digging into the butter and helping to create even more of these microscopic air bubbles. Those air bubbles will expand when heated in the oven, like balloons, making the cookie rise.

2. Don’t Over Mix!

Once you have creamed the butter and added any other liquids, it’s time for the flour - always the last ingredient! But, don’t overdo this step, otherwise you will end up with tough cookies. When combining wet and dry ingredients, mix just until incorporated. Overmixing can develop gluten in the flour, resulting in tough cookies instead of tender ones. Why is that?

Gluten, a protein, is the structural component of most baked goods.Think of gluten as the framework of a house. The flour in your recipe is like a pile of building materials, and when you mix with the wet ingredients, you activate the workers (enzymes) that connect the beams (gluten proteins) with nails (water molecules). As you knead or mix the dough, these workers build a strong network, creating gluten that gives structure to your baked goods.

In bread, you want a robust framework, like a multi-story house, to trap air and create a chewy texture. For cakes and pastries, you need less structure—similar to a single-story house—so the texture remains tender. In cookies, minimal structure is ideal, like in a temporary shelter that holds together but is easy to break apart. Over-mixing can lead to a stiff, tough result, just like over-building can make a house rigid and uncomfortable. Different baked goods require varying amounts of mixing and flour types to create the desired "buildings" with their gluten framework!

‍3. Chill The Dough

Chilling the dough helps the cookies to keep their shape after cooked and to make them darker and more flavorful. But why?

When you chill cookie dough, the butter in the recipe solidifies, right? That's because the melting point of butter is much higher than the fridge temperature. This means that when the chilled cookies are placed in the oven, the fat part takes longer to melt and allows time for the rest of the dough to cook and solidify, maintaining their shape.

Also, while the cookie dough is chilling in the fridge, literally, some of the moist will evaporate, and also the sugar in the dough will absorb more of the moist content, forming a more saturated solution. That means that this saturated solution, when baked, will caramelize more, producing more color and more flavor!

I hope this all makes sense, and if you want to put it all in practice, you can try this delicious zesty, lemony sugar cookie recipe!

Lemony Holiday Sugar Cookies Recipe

Yield:

12-15 cookies (multiply the recipe for bigger batches)

Ingredients:

Cookie Dough

• 7 Tbsp unsalted butter  at room temperature
• ¼ cup granulated sugar
• 1 tsp fresh lemon juice
• 2 tsp lemon zest
• ½ tsp kosher salt
• 1 cup AP flour 
• Flour for dusting*

Lemon Glaze

• 1 Tbsp fresh lemon juice
• ½ cup powdered sugar
• Pinch of kosher salt
• Finely grated lemon zest, for garnish

‍Instructions:

1. Preheat oven. Turn on to 350°F.
2. Make dough. In a large bowl, using a handheld electric mixer, beat butter with powdered sugar until very smooth (2 minutes). Scrape bowl as needed. Add lemon juice and lemon zest, beating until smooth (1 minute). Mix in flour gently until just incorporated. Dough will be semi-firm and rollable without chilling. Divide dough in half; refrigerate one half.
3. Roll dough. On a lightly floured parchment paper, roll first dough half to ¼" thickness. Use floured cookie cutter to punch out desired shapes. Add flour as needed to prevent sticking.
4. Prepare for baking. Transfer shapes to 2 parchment-lined baking sheets, spacing 1 ½" apart.
5. Bake cookies. Place first sheet in oven. Rotate after 5 minutes. Continue baking until edges are golden brown (10-14 minutes total).
6. Repeat process. Follow steps 3-5 with remaining refrigerated dough.
7. Cool completely. Let cookies rest on baking sheet (10 minutes), then transfer to wire rack.
8. Make glaze. In a small bowl, whisk lemon juice, powdered sugar, and salt until smooth. Aim for thick heavy cream consistency.‍
9. Decorate. Pour glaze onto small plate. Gently press cookie top into glaze, letting excess drip off. Sprinkle with lemon zest. Place on wire rack set inside rimmed baking sheet. Let set (minimum 30 minutes).

Enjoy!

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