Century eggs—also known as preserved eggs, thousand-year-old eggs, or 皮蛋 (pídàn) in Mandarin—are one of the most iconic and polarizing foods in Chinese cuisine. With their dark, translucent “jade-like” whites and creamy, pungent yolks, these eggs evoke intrigue, tradition, and a wealth of culinary possibilities.

Contrary to their nickname, century eggs are not actually hundreds of years old. They are typically preserved for several weeks to months in a mixture of clay, ash, salt, quicklime, and rice husks, resulting in a rich, umami-packed egg that is safe and flavorful when prepared correctly. However, like all preserved foods, there are proper methods for storing, preparing, and consuming century eggs to ensure both enjoyment and health.

In this article, we’ll dive into the origins of century eggs, how they are made, and most importantly, how to use them properly in modern cooking without compromising their taste or nutritional value.

1. What Are Century Eggs?

Century eggs are made from duck, chicken, or quail eggs that undergo a preservation process involving alkaline materials. This changes both their appearance and chemical composition:

• Whites turn into a dark amber jelly
• Yolks become creamy, green-gray or dark and pungent

Key Characteristics:

• Strong umami flavor with sulfur and ammonia notes
• Gelatinous texture with a soft, spreadable yolk
• No cooking required (already preserved)

Century eggs have been consumed in China for over 600 years and remain popular across Asia in countries like Vietnam (trứng bắc thảo), Thailand, and Taiwan.

2. The Science Behind the Preservation

The unique transformation of century eggs is not due to rotting or fermentation, but rather an alkaline curing reaction:

• pH increases inside the egg
• Proteins in the white denature and solidify into a jelly
• Fats in the yolk break down, releasing ammonia

No artificial color is necessary. The green and black hues come naturally from the chemical reaction.

Modern producers often shorten curing time using alkaline salts like sodium carbonate rather than traditional lime and ash, making them more consistent and safer.

3. Choosing Quality Century Eggs

Before using century eggs, it’s essential to choose safe and high-quality products, especially because these eggs are consumed without further cooking.

What to Look For:

• Vacuum-sealed or individually wrapped eggs
• No cracks in the shell
• No chemical smell upon opening
• Proper expiration dates on packaging

Avoid:

• Eggs with leakage or sliminess
• Overpowering ammonia odor (a mild scent is normal)
• Artificial-looking colors

If buying from a local Asian market, choose reputable brands and avoid any unlabeled, loose eggs unless you are familiar with the source.

4. Proper Storage of Century Eggs

Century eggs are shelf-stable but require care to maintain quality.

Unopened:

• Store in a cool, dry place
• Shelf life: up to 6 months
• Keep out of direct sunlight

After Opening:

• Peel the shell and rinse off any clay residue
• Store peeled eggs in an airtight container
• Refrigerate and use within 3–5 days

Never freeze century eggs, as freezing destroys their texture and flavor.

5. How to Peel Century Eggs Correctly

Peeling century eggs requires gentle handling, especially since the whites are jelly-like and prone to tearing.

Steps:

1. Tap the shell lightly to create cracks
2. Roll the egg gently on a hard surface
3. Peel under running water to remove residue
4. Rinse thoroughly
5. Pat dry with paper towel

Optional: Soak briefly in cold water if the eggs are too salty or smell overly pungent.

6. Ways to Use Century Eggs in Cooking

While many people are unsure how to incorporate century eggs into meals, they are extremely versatile and can be enjoyed in both traditional and modern dishes.

6.1. Century Egg and Tofu (皮蛋豆腐)

• Cold appetizer
• Silken tofu topped with diced century egg, soy sauce, sesame oil, scallions
• Garnish with bonito flakes or pickled ginger

6.2. Congee with Century Egg (皮蛋瘦肉粥)

• A classic comfort dish in Cantonese cuisine
• Rice porridge with lean pork and chopped century egg stirred in
• Topped with fried shallots and fresh coriander

6.3. Century Egg Salad

• Combine century egg wedges with cucumber, garlic, chili oil, and vinegar
• Light, spicy, and perfect as a side dish

6.4. Century Egg Pastries

• Used in Chinese pastries or mooncakes
• Often paired with sweet or savory fillings like lotus seed paste

6.5. Century Egg Fried Rice

• Diced century eggs stir-fried with rice, scallions, and soy sauce
• A quick and flavorful twist

7. How to Balance Flavor and Presentation

Due to their bold taste and unique color, century eggs benefit from pairing with mild, cooling, or tangy ingredients to balance flavors.

Pair With:

• Tofu (silken or firm)
• Vinegar and soy-based sauces
• Pickled vegetables
• Rice porridge
• Ginger or garlic

Tips for Presentation:

• Slice with a wet knife for clean edges
• Use in wedges or thin slices for visual appeal
• Pair with bright colors (greens, whites, reds) for contrast

8. Cultural Significance of Century Eggs

Century eggs are more than just food—they are a symbol of culinary heritage and regional pride in Chinese culture.

Symbolic Meanings:

• Longevity and tradition
• Preservation of ancient techniques
• Nostalgia for home-style cooking

They are often served during festive meals, banquets, or used as gifts during important celebrations.

9. Health Considerations and Safety

Century eggs are safe to eat when properly produced and handled. However, some concerns have arisen around additives or lead contamination in cheaper versions.

Modern Safety:

• Most century eggs today are lead-free, using safe alkaline agents like sodium carbonate and calcium hydroxide.
• Always choose brands labeled “no lead added”.

Nutritional Value (per 1 egg):

• Calories: ~70–90
• Protein: 6–7g
• Fat: 5g
• Carbs: <1g

Low-carb and high-protein, century eggs are suitable for keto and low-carb diets.

10. Common Mistakes When Using Century Eggs

Avoid these pitfalls when preparing century eggs:

❌ Mistake 1: Not Rinsing or Peeling Properly

Leftover ash or clay can affect taste and hygiene.

❌ Mistake 2: Serving Too Cold

Let eggs come to room temperature before serving for better flavor.

❌ Mistake 3: Overpowering Dishes

Avoid overly spicy or sweet recipes that mask the egg’s unique flavor.

❌ Mistake 4: Using with Rich Meats

Too many bold flavors can compete with the umami of century eggs.

11. Creative Modern Uses

Innovative chefs are now experimenting with century eggs in modern cuisine:

• Century egg deviled eggs
• Sushi with preserved egg yolk topping
• Century egg carbonara
• Century egg ramen broth
• Fusion tapas with egg mousse

The unique flavor profile—salty, earthy, and umami-rich—makes century eggs a secret weapon in upscale, experimental kitchens.

12. Final Thoughts: Embracing a Bold Culinary Legacy

Century eggs may look intimidating at first, but when used properly, they open a world of flavor and tradition that is unmatched. Their complexity, heritage, and culinary versatility make them a treasure of Chinese cuisine.

By learning how to:

• Choose quality eggs
• Peel and store correctly
• Balance flavors in dishes
• Pair with appropriate ingredients

…you can fully appreciate this ancient ingredient in both traditional and contemporary meals.

Whether you’re hosting a Chinese-themed dinner, exploring Asian ingredients, or revisiting family recipes, give century eggs a place at your table—prepared with knowledge, respect, and a touch of creativity.