The South East Asian history of preserving eggs in salt stretches far back into the mists of time.
While the exact origin is unknown, they far predate their closest relative - century eggs - which originated in China during the Ming Dynasty period.
Many believe the earliest recorded mention of salted duck eggs was in the Qimin Yaoshu, an ancient Chinese agricultural text that dates back to the 5th century, 600 years earlier than the origination of century eggs.
While they originated in China, they’ve gone on to become a staple in many countries across Asia, from Singapore, to The Philippines. So, with that said, how exactly do you create a salted duck egg, and what dishes feature them heavily?
Before modern technology and an increased demand for eggs on a global scale, salted duck eggs started their journey in the seafaring communities of Eastern asia.
Salted duck eggs were buried in the sand, where the salty sea water would penetrate the shell of the egg over time, then once the desired amount of salinity was achieved, the egg would be retrieved.
But with trade, and the gradual movement of people and information over time, the process quickly moved inland, where salt water or dried salt was used to replicate the conditions of the sea.
Early adopters would bury the eggs in forests over a period of time, and dig them up once the required flavour and texture had been achieved. But to do so, they had to be buried in clay, mud, or even termite mounds in some parts of the world, largely because normal earth didn’t adhere the saltwater to the eggs in the right way.
These old methods were sufficient to keep up with the demand of a small village centuries ago, but as time passed and demands grew, industrialised methods of enveloing duck eggs in salt water were required. Now even the salted yolk can be sold separately.
If you’re intrigued by the idea of creating your own, and trying to produce this unique flavour and texture our chef Mark Corbyn shows you how to make them on our Rassa Filipino course.
But what does a salted duck egg taste like? What’s the difference in texture between a salted egg and a regular one?
One week will result in an egg with a subtle hint of salt and a firm yolk that can be fried or steamed over some minced meat. Two weeks to a month and you’ll have eggs that have a salty white and firm salty egg-yolks. The hallmarks of a perfect egg can be found in it’s yolk though - you’re looking for a dry texture with a deep, almost luminous orange colour to it.
What dishes use salted duck egg? Well, there’s a whole host of recipes that these salty delights work for - from Salted Egg Yolk Chicken wings, through to the famous ‘Salted Duck Egg’ flavoured ice cream from Tom’s Palette in Singapore. But I’m going to talk to you about the Filipino favourite, Arroz Caldo, created by Mark Corbyn as part of the same Filipino course we offer here at Rassa.
Arroz Caldo (Filipino rice broth) is a take on the classic asian rice porridge, congee. It’s recognised as a comfort food and as you’ll later learn, is often used in a medicinal way according to traditional remedies.
In the Philippines, rice porridges are generally known as ‘lugaw’ in Tagalog, something that was introduced into the country by Chinese traders. However, the Arroz Caldo was re-christened during the Spanish colonial era, with any number of additions such as meat or aromatics being included.
Now a cornerstone of Filipino home cooking, the dish today often includes condiments like garlic, spring onions, calamansi, and of course - the salted duck egg.
Are salted duck eggs good for you? Well - according to Traditional Chinese Medicines, salted duck eggs are said to lower feverish symptoms - and Arroz Caldo, with a salted duck egg is a traditional home remedy for an upset stomach.
Duck eggs in general contain around double the amount of cholesterol to a standard chicken egg, and in comparison to a duck egg - they have higher levels of protein, more fat, and are a better source for potassium and calcium. That said, the payoff is a reduction in iron and general vitamins.
Generally speaking, like most things, these salty treats are good in moderation, and can provide you with some of the nutrients you need in one delicious salt-punch.
One thing to look out for though - is where your eggs have come from. China and Vietnam are the two biggest producers of the eggs, and there have been a number of scandals in the past, from eggs being brined in contaminated industrial salt, to ducks being fed Sudan Red IV dye to darken the egg yolks (it's carcinogenic). While it’s hard to know what’s gone into the egg, the best thing to do is steer clear of unmarked eggs, or eggs with no clear point of origination.
Let us know what you end up creating with your salted duck eggs, and let us know if you make your own!