The Spanish Tortilla: History, Evolution, and Recipes

The tortilla de patatas, or Spanish tortilla, is one of the most iconic dishes in Spanish cuisine. Made primarily from potatoes, eggs, and olive oil, it has stood the test of time, becoming a symbol of simplicity and conviviality. But what is the exact origin of this dish? How has it evolved over time? And most importantly, does an "authentic" recipe exist, or does the Spanish tortilla come in many different variations?

History and Evolution of the Spanish Tortilla

1. "El Cocinero Moderno" (1828) by José María de la Cueva
   This book is one of the first to document Spanish culinary recipes in the 19th century. While the tortilla de patatas is not explicitly mentioned, it refers to recipes that include eggs and potatoes. These dishes could have been direct ancestors of the modern tortilla. José María de la Cueva, a respected chef of his time, played a central role in documenting classic Spanish recipes. His work is considered a key reference for 19th-century Spanish cuisine.

2. "La Cocina Española Antigua" (1839) by Pedro de la Vera
   In this work, Pedro de la Vera dedicates a large part of his book to historical Spanish cuisine. Although the tortilla de patatas is not specifically mentioned, he describes several potato-based recipes, and it is likely that these dishes inspired the creation of the tortilla as we know it today.

3. "La Cocina de los Españoles" (1840) by Domingo Hernández de Maceda
   One of the greatest culinary authors of 19th-century Spain, Domingo Hernández de Maceda, presented recipes in his book that show a strong influence of the use of potatoes and eggs. While the tortilla de patatas is not explicitly mentioned, the concept of mixing eggs and potatoes seems to be taking shape.

4. "La Enciclopedia Culinaria" (1861) by Manuel María González
   Manuel María González’s encyclopedic work contains an entire section on omelets and egg-based recipes. The idea of a dish combining potatoes and eggs in an omelet-style dish gradually develops, but the tortilla de patatas, as we know it, is not yet explicitly described.

5. "El Libro de Cocina" by Francisco Martínez
   In his works, 19th-century chef Francisco Martínez addresses common Spanish recipes. Although the tortilla de patatas is not mentioned, ingredients such as potatoes in similar dishes suggest that the tortilla de patatas was in the making.

The Emergence of the Tortilla de Patatas
The tortilla de patatas as we know it today seems to have emerged at the end of the 19th century, although the first mentions of the dish in popular writings appear in the 20th century. The dish was popularized in the 1920s by influential chefs who helped make the tortilla a true culinary symbol of Spain. Today, it is recognized as a national dish.

Variations of the Spanish Tortilla: With or Without Onion?
One of the most heated debates surrounding the Spanish tortilla is whether or not to include onion. Some claim that onion is an integral part of the dish, while others believe that adding onion is a modern deviation from the original recipe.

1. Tortilla with Onion
   Supporters of the tortilla with onion argue that this ingredient adds sweetness and complexity to the dish. Here are the main reasons for this version:

   • Sweetness and depth of flavor: Caramelized onion adds sweetness that balances the richness of the potatoes and eggs.
   • Texture: Onion adds a melting texture that contrasts with the potatoes.
   • Regional tradition: In certain regions, such as Catalonia, adding onion is common and part of the local tradition.

2. Tortilla without Onion
   On the other hand, purists prefer the version without onion, which emphasizes the simplicity of the dish. Here are the reasons for this version:

   • Traditional recipe: Some believe that the original tortilla de patatas, dating back to the 19th century, did not include onion.
   • Lighter flavor: The absence of onion keeps the taste neutral and lighter.
   • Culinary purism: For purists, onion is a modern innovation and not part of the original recipe. They prefer a simpler tortilla, made only with potatoes, eggs, salt, and oil.

Examples of Regions and Variants:

• Madrid and Castile-La Mancha: The version without onion is the most common.
• Catalonia: Onion is frequently added to the tortilla in this region.
• Andalusia: The Andalusian tortilla may include onion, although in rural areas, the version without onion is also popular.

Recipe for Tortilla de Patatas (without Onion)
Ingredients:

• 4 potatoes (preferably varieties like "Agria" or "Yukon Gold")
• 6 eggs
• 100 ml extra virgin olive oil
• 10 g salt
• Black pepper (to taste)

Preparation:

1. Preparing the potatoes:

   • Peel the potatoes and cut them into thin slices (about 2-3 mm thick). Traditionally, the potatoes are cut by hand, but a mandolin can be used if necessary.

2. Cooking the potatoes:

   • Heat the olive oil in a large pan (about 24 to 26 cm in diameter) over medium heat.
   • Add the potatoes and cook them over medium-low heat for 20-25 minutes until tender but not fried. They should be lightly confited.
   • Stir regularly to prevent them from sticking. Once cooked, remove them and place them in a strainer to remove excess oil.

3. Preparing the eggs:

   • Beat the eggs in a large bowl, then add a pinch of salt and pepper.

4. Mixing the potatoes and eggs:

   • Let the potatoes cool slightly before gently adding them to the beaten eggs. Mix well so that the potatoes are fully coated with egg without breaking them. Let this mixture rest for 5 minutes.

5. Cooking the tortilla:

   • Pour some olive oil into the same pan and heat over medium heat.
   • Pour the potato-egg mixture into the pan and cook for 5-7 minutes until the bottom is golden and the edges start to detach.
   • To flip the tortilla, use a large flat plate or a lid. Place the plate on the pan, flip the tortilla, and gently slide it back into the pan to cook the other side. Cook for another 3-4 minutes.

6. Resting and serving:

   • Let the tortilla rest for a few minutes before cutting it into slices. It can be served hot, at room temperature, or cold.

Additional Tips:

• Texture: For a creamier tortilla, cook it less at the center. If you prefer a firmer tortilla, extend the cooking time slightly.
• Olive oil: Use good quality extra virgin olive oil for a richer taste.
• No onion: This recipe does not include onion, following the traditional version.

Conclusion
The tortilla de patatas, with or without onion, remains one of the most representative dishes of Spanish cuisine. Whether you prefer the sweeter and richer version with onion or the simpler and lighter version without, this dish perfectly embodies the authenticity and simplicity of Spanish gastronomy.