Science of Macarons

We've all heard the phrase 'baking is a science,' right? Well, some baked goods certainly have more leeway than others.

Macarons, for instance, are incredibly scientific, and one wrong move or miscalculation can cause them to fail. They are well-known for their finicky and temperamental nature, but that does not make them impossible to master.

❔ What Are Macarons?

Macarons are a delicate variety of treats that feature two baked almond meringue cookies sandwiched together with a sweet and creamy filling. The inside of the cookie has endless possibilities, from ganache to buttercream frosting flavors and even citrus curds or jam.

In fact, you really can't mess up the filling. Be as creative as you like!

The shells (or the outside cookies) are the real technical part of this dessert that makes them so difficult to master.

What is A Perfect Macaron Shell

The outside of the shell should be crispy, while the inside has a perfectly chewy texture. The shell should also be completely full and not have any air bubbles or hollow areas.

Macarons she's should have smooth tops with an even, slightly domed surface. The edges should be straight with a bubbly layer of baked meringue at the bottom (called 'feet').

❔ What Are Macarons Made Of?

No matter what recipe you use, macarons are always made up of four fundamental ingredients that cannot be substituted: almond flour, confectioners' sugar, egg white, and granulated sugar.

Some recipes will include additional ingredients, such as extracts, but they are not necessary for making macarons.

Ingredient	Function
Almond Flour	Protein, flavor, structure, texture
Confectioners' Sugar	Sweetness, bulk, texture
Egg Whites	Structure, meringue, emulsification
Granulated Sugar	Meringue structure, sweetness

🍪 Different Macaron Methods

There are French, Italian, and Swiss macarons. While all three of these have the same ingredients and overall process, there is one major difference between these methods: the type of meringue.

French

French macarons use French meringue, which is made by beating egg whites, slowly adding granulated sugar, and continuing to beat until you have stiff peaks. This is a popular method as it is very simple, and there is no heat involved.

While it is easy to do, it does not create the most stable meringue, which could lead to inconsistencies in your macarons.

Italian

For Italian meringue, a combination of sugar and water is heated in a small saucepan on the stovetop. Once it reaches a specific temperature, it will be slowly drizzled into egg whites while they are being beaten in a mixer.

This method is slightly more technical than making French meringue, but you will achieve a sturdier meringue that is easier to work with.

Swiss

Swiss meringue also involves the use of the stovetop. This method uses a double boiler to combine the egg whites and sugar.

Once heated, they are then whisked into a meringue. Which again, gives you a sturdier meringue.

🥣 Equipment Needed To Make Macarons

Making macarons requires the right tools for precision and success. You'll want to gather these items before you try your hand at making macarons.

1. Kitchen scale. Precision is everything when making macarons. A digital kitchen scale lets you measure your ingredients accurately, which is crucial.
2. Stand mixer or hand mixer. A stand mixer with a whisk attachment is best for making meringue as it can whip the egg whites evenly and consistently. A hand mixer works as well but requires a little bit more effort.
3. Mixing bowls. You’ll need a clean, grease-free medium mixing bowl for whisking your egg whites. Stainless steel or glass bowls are what I recommend as the best choices because plastic can retain traces of oil that might affect your meringue.
4. Spatula. A flexible silicone spatula is perfect for folding the meringue with the dry ingredients during the macaronage process. Controlled and gentle folds are important to reach the perfect macaron batter consistency.
5. Sifter or fine mesh strainer. Sifting your almond flour and powdered sugar is important for a smooth batter.
6. Piping Bag with a round tip. A piping bag or 'pastry bag' fitted with a plain round tip (usually a size 10-12 tip) will help you pipe uniform macaron shells onto your baking sheet.
7. Silicone baking mats or parchment paper. Silicone baking mats are reusable and provide a non-stick surface so your macarons release easily from the baking sheet. Parchment paper works as well, although I love the convenience of my reusable baking mats.
8. Baking sheets. Heavy-duty, flat baking sheets provide even heat distribution, which is key for baking macarons.
9. Cooling rack. Your baked macaron shells need to cool completely before you can fill them. A cooling rack lets air circulate, helping the shells cool faster and prevent condensation.
10. Oven thermometer (optional). Since oven temperature is critical for macarons, and all ovens are different, an oven thermometer can help you verify your oven's temperature.
11. Dehumidifier (optional). If you’re making macarons in a humid environment, a dehumidifier can help create better macaron conditions. Alternatively, a small fan can speed up the resting process by helping the shells form a skin.

🔬 Macaron Science

One of the biggest factors in making macarons is being able to control the amount of air in your batter. This can be done in two ways: making the meringue and then the macaronage process.

Science of Meringue

Meringue is an airy, light substance made by whipping together egg whites and sugar.

Egg whites are 10% protein and 90% water. The protein found in these egg whites traps the air when being whipped at high speed, creating structure.

When you are whisking the egg whites, the proteins gradually begin to unfold, which creates a mesh-like barrier that can then trap the air. The role of the added sugar is to stabilize the trapped air.

The longer this mixture is whipped, the more 'stiff' the peaks become. At first, the meringue will be very soft and hold no shape. The longer it is beaten, the more structure it obtains and the more it can hold its shape.

For macarons, you want a stiff meringue with peaks. This is when you lift the whisk out of the bowl, and the meringue sticks straight up and does not droop at all.

❔ What Is Macaronage?

Macaronage is the process of folding together the meringue with the dry ingredients (almond flour and powdered sugar).

While you spent all that time adding air to create your meringue, the macaronage process is meant to eliminate air from the batter.

The gradual folding process slowly knocks the air out of the meringue until you have a batter with the perfect amount of air.

🌡️ Temperature and the Environment

As if finding the perfect balance of air wasn't enough, the environment itself can cause its own host of issues.

Humidity

For one, humidity can play a factor in how long you need to rest your macarons. This resting time period is crucial, as it allows the macarons to dry just enough to form a thin skin.

When baked, this skin prevents the air from escaping the tops of the shells and forces it out the bottom instead (which creates the feet).

Many people won't even attempt to make macarons on a rainy day due to the level of moisture in the air (generally speaking, this is me!). You only need to increase the resting time or even place your macarons to rest next to a dehumidifier.

Oven Temperature

The temperature of your oven can also be a make-or-break moment for macarons. I'm not just talking about a general temperature either, but more so that even a couple of degrees difference could cause the downfall of these cookies.

If your oven is too hot, the steam will release too quickly and cause the shells to crack. If it is too cold, your macarons will become wrinkly.

Most recipes will fall between 275°F-325°F (135°C-160°C). This wide range means you will need to experiment to find what temperature works best for your oven.

I also recommend picking up an oven thermometer, as sometimes ovens are not accurate. Alternatively, you can have a tech come out and service your oven. Be sure to ask them to calibrate the thermometer for accuracy.

💭 Tips for Making Macarons

• Clean your equipment. Use vinegar or lemon juice to wipe down your whisk and mixing bowls. Even the tiniest amount of trace fat or oil can cause your meringue to not be able to properly form.
• Get an oven thermometer. An oven thermometer is an inexpensive way to ensure that your oven is at the proper temperature.
• Let the shells rest. Resting could take anywhere from 30 minutes to 2 hours. You'll know they are ready to bake when you can gently poke them, and nothing sticks to your fingers.

I hope this article covering the science of macarons has helped give you a better understanding of these amazing cookies. Leave a comment, and let me know what you think.

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