The recipe for a masterpiece: panettone according to science

What is a panettone? An Italian Christmas sweet? An extra-large loaf? A calorie bomb? A dough made of gluten networks, gelled starches, sugars, flavorings, and air pockets? The answer is that it's all of these things, as it depends on your perspective. What seems undeniable is that we are looking at a culinary masterpiece.

From Italy to the world

Panettone is a very famous Italian sweet bread enjoyed worldwide, especially at Christmas. It has a typical dome shape and is approximately 12 to 15 centimeters tall. For several years now, it has also become very popular in Spain, where it shares the table with other traditional Christmas sweets such as turrón, polvorones, and roscón de Reyes. All these products are delicious and associated with happy, even magical, moments with family and friends.

Although magical It's a very nice term, especially for children. It's worth remembering that all these products have a solid scientific basis. Everything we eat is science, and thanks to science we can enjoy these Christmas wonders.

Gastronomically speaking, a panettone can be defined as a type of brioche bread, thick and spongy, made with sourdough and strong flour, which requires several fermentations, resting periods, and even an upside-down turn!—something quite unusual. A master baker could give a more beautiful description, but I happen to be a food technologist, so it falls to me to describe it from a scientific point of view.

More gluten, more volume

The first step in making panettone is preparing the preferment. For this, we use strong flour, which provides more protein capable of forming gluten, a viscoelastic network similar to a mesh, which acts as a construction capable of trapping gas and adding volume to the product. This is why gluten-free products have a great deal of difficulty imitating panettone. We also add sourdough starter and/or salvo bakery starter, that is, the live microorganisms that will ferment the dough, generate CO₂, aromas and flavors, and soften its texture.

Sourdough starter, to put it simply, is dough in which live microorganisms have been kept, matured, and generated more complex aromas and flavors. To make a kind of comparison, a sourdough starter is like an AI in its latest updates, with faster and more sophisticated responses, while a freshly made dough with fresh yeast is like a more basic AI, functional but not complex.

Water, sugar, butter, and egg yolks are also incorporated, ingredients that hydrate and provide food for the microorganisms (sugars), as well as enzymes and fats. Panettone dough is special because it must be both flexible and resistant. It must stretch to grow, but without breaking. That's why it requires long, careful fermentations that allow the internal structure to develop properly and stably.

Kneading, gases, and aromas

It is very important to knead correctly, using folding motions, so that all the ingredients are well integrated and the gluten network begins to form. Little by little, the mixture becomes a dough; the starch in the flour hydrates and its amylose and amylopectin chains (starch molecules) extend, causing the mixture to thicken. This kneading process, of variable duration, ends with a first dough that is placed at room temperature for approximately two hours, so that the yeasts can ferment the sugars (this is the simplest process; later they will seek out other components), and generate gases (responsible for the bubbles) and aromatic compounds such as aldehydes. The lattice of the panettone

After this first prefermented dough or first impastoA second batch of the same ingredients is added, along with salt, vanilla, orange zest, and chocolate chips (raisins or other fruits can also be used). This new mixture is kneaded again and left to rest for the same amount of time, allowing the structure to integrate the new ingredients and the yeast to continue fermenting the dough and generating gases, flavors, and aromas.

When the dough has doubled in volume, it is divided, portioned, and shaped into a tight, round ball. The number of balls depends on the desired number of panettone. It is important that this step is done quickly to avoid degassing the dough too much or disrupting the structure, which is already formed by a continuous phase combining the gluten network with the gelled starch granules, along with a dispersed phase composed of gas trapped in alveoli.

Once the pastries The dough balls are placed inside typical panettone molds and left to rise until they double in volume. Once risen, their tops can be brushed with egg yolk or powdered sugar, which will protect the surface during baking and prevent excessive drying or burning.

The oven and the dome

Baking in the oven for about 40 minutes at 180°C (350°F), always in a preheated oven, will cause the dough to transform physically and chemically, reach its final volume, and undergo caramelization, protein denaturation, and Maillard reactions (which give it its color and toasted aroma). The gluten networks consolidate, the starch hardens, and the dough's springiness, sponginess, and air pockets become fixed. To check if baking is complete, we use the traditional toothpick or knife test: if it comes out clean, it's done; if it comes out with batter on it, it needs a little more time. Once out of the oven, a very characteristic step follows: turning it upside down. This is done to prevent the panettone from collapsing. The dough is still very hot and can sink. As it cools, the internal structure will be fully consolidated and it won't collapse. This is common, for example, when making a sponge cake, but considering that panettone is very tall, if the dough were to sink, the result would be a much more compact and hard product, not as spongy and soft.

There's also a scientific basis for this, as what happens is the retrogradation of the starch's amylose during cooling, which rearranges and fixes the spring structure. With this, our panettone is finished, beyond any external decorations, which depend on personal taste and marketing.

And the last step: eating it. It truly is magical that we can enjoy such a wonderful treat. Happy holidays!

This article was originally published in The Conversation.