Do you know why the boiled egg served as a topping for ramen (which is called Ramen Egg) is so tasty? It’s because the soft-boiled egg is marinated in a soy-based sauce and is full of umami. The outer layer of the egg white absorbs the flavour of the marinade and stains the egg light brown colour.
Ramen Egg is basically a marinated soft-boiled egg (it can also be hard-boiled). When you cut the egg in half, you can see the brown-coloured layer on the outside of the egg white and the orange-yellow egg yolk oozes out. It looks so appetising.
Although I call it Ramen Egg since it is often added to a bowl of ramen, it is also served as a side dish or a starter for drinks in Japan. Perhaps that’s why Japanese people call it ‘ajitsuke tamago‘ (味付け卵/味付け玉子), rather than calling it a name that associates it only with ramen.
The word ‘ajitsuke‘ (味付け) means flavoured and ‘tamago‘ (卵/玉子) means egg. Some people use the abbreviated name, ‘ajitama‘ (味玉) by shortening each word.
Soft-boiled Egg is the Key
I think that a soft-boiled egg looks better than hard-boiled egg when it is cut open. When you use it as a ramen topping, you halve the egg to show the egg yolk in the centre. Imagine the yolk slightly runny in the centre. It looks so good.
I think soft-boiled egg can even be classified into three ways, depending on how runny the yolk is:
- Completely runny egg yolk – in this case, the egg white is very soft and fragile.
- Semi-runny egg yolk – the outer edge of the yolk is cooked but the centre of the yolk is runny and the yolk oozes out when the egg is cut open. The egg white is adequately firm. This is what I made today.
- Soft egg yolk – the egg yolk does not ooze out when cut open. The centre of the yolk is not completely cooked while the outer edge of the yolk is cooked.
In my recipe, I included how to make a soft-boiled egg perfectly. I tried many ways of boiling eggs and finally I found the method that gave me a consistent outcome every time.
What is in my Ramen Egg
All the ingredients below with exception of the eggs are for the marinade.
- Chilled eggs (about 55g / 1.9oz each)
- Soy sauce
- Cooking sake
- Bonito flakes
The size of your eggs matters. I buy a carton of 12 eggs with a total weight of 660g / 23.3oz. The average weight of the eggs should be 55g / 1.9oz, but I get a mixture of 50g – 60g / 1.8-2.1oz eggs. If your eggs are smaller/larger, you need to boil for about ½ minute shorter/longer respectively.
The amount of water in the marinade determines the strength of the flavour. The ratio of water used in my recipe is suitable for marinating eggs for about 8-10 hours.
If you are intending to leave the eggs in the marinade longer, you should add more water otherwise the eggs become too salty. Similarly, you should reduce the water if you only have a few hours to marinate. Exactly how much to increase/decrease the water needs to be worked out by trial and error as each person has a different level of sensitivity to the saltiness.
How to make Ramen Eggs
To minimise the wait time, I make the marinade first, then boil eggs while cooling down the marinade . But you can of course boil the eggs first if you prefer.
- Put all the Marinade ingredients in a pot, bring it to a boil
- Transfer the marinade to a bowl through a sieve to remove the bonito flakes.
- Fill a saucepan with more than enough water to submerge the eggs and bring it to a boil.
- Using a ladle or a small sieve, gently put the eggs in the boiling water.
- Reduce the heat to medium and boil for 6½ minutes.
- Drain and quicky cool the eggs down in ice water.
- Peel the eggshells and marinate in the Marinade for 8-10 hours.
6½ minutes of boiling time makes the yolk semi-runny. 6 minutes will make the yolk completely runny. 7 minutes will make the yolk not runny at all, but the centre will not be completely cooked through.
The marinade of my Ajitsuke Tamago includes bonito flakes that gives you a great degree of umami in addition to the umami from the soy sauce, cooking sake, and mirin.
My way of boiling eggs
There is a good reason why I add chilled eggs after the water starts boiling:
- Depending on the size of your pot, the amount of water you put in the pot, and the temperature of your stove, the time taken to bring water to a boil varies a lot. When the window of the boiling time is so narrow to make the yolk runny/not runny, you can’t afford to have these variations.
- Using chilled eggs direct from the fridge is also to minimise the variables. Room temperature can be 15°C / 59°F or 30°C / 86°F depending on where you live.
Adding chilled fresh eggs to the boiling water eliminates these inconsistent factors and you will get more consistent results.
I used to have trouble peeling the shells of boiled eggs. The shells were stuck to the membrane of the egg so hard that a piece of egg white came with the shell, resulting in bumpy surface of the boiled egg. But not anymore!
Before boiling, I make a little hole on the round end of the egg using a needle. It seems to separate the membrane from the shell, allowing the shell to peel off easily.
In Japan, Ajitsuke Tamago is as well as being used as a topping for ramen (hence it is called Ramen Egg), it is also served as an appetiser at izakaya (Japanese-style tavern) and as a side dish to go with cooked rice.
It keeps only a few days in the fridge, but you can make it again so easily. The marinade can be reused for a couple of times as long as you boil it after use. Alternatively, you can use it in place of a sauce that is sweet-soy flavour such as Oyako-don sauce and Teriyaki sauce, with some flavour adjustments.
Ramen Egg is a soft-boiled egg marinated in soy-based sauce that is full of umami. The outer layer of the egg white absorbs the flavour of the marinade and stains the egg a light-brown colour.
Ramen Eggs are served not only as a ramen topping but also a side and as nibbles for drinks.
Don't forget to see the section 'MEAL IDEAS' below the recipe card! It gives you a list of dishes that I have already posted and this recipe that can make up a complete meal. I hope it is of help to you.
- 4 eggs (about 55g / 1.9oz each, chilled)
Put all the Marinade ingredients into a small saucepan and bring it to a boil. Cook for a minute or so, ensuring that the sugar dissolves completely.
Put the sauce into a small bowl through a sieve to remove the bonito flakes. Press down the bonito flakes in the sieve with the back of a spoon and squeeze out the liquid (note 2). Let it cool.
Fill a saucepan with water deep enough to boil eggs and bring it to a boil.
(Optional but recommended) Using a needle and a small hammer or the side of the kitchen scissors, make a tiny hole on the round end of the egg (see the photos in post).
Using a ladle, gently place the eggs one-by-one in the boiling water. You may want to gently roll the eggs for the first ½-1 minutes to position the egg yolk in the middle.
Reduce the heat to medium and boil for 6½ minutes (note 3).
Drain the boiling water and transfer the eggs to a bowl of iced water to quickly cool them down (note 4).
Gently crack the eggshell all around the egg, then peel the shells. Make sure that you remove the thin membrane pieces on the egg.
Pat-dry the boiled eggs and place them in a zip lock bag.
Add the marinade to the bag with eggs. Remove air from the bag as much as possible, then seal (note 5).
Store in the fridge for 8-10 hours. Rotate the eggs after 4 hours to evenly marinate the eggs.
Cut each egg in half using a thread by wrapping the thread around the egg or sliding the thread through the egg (note 6).
Serve two halves as a topping for a ramen, an izakaya-style side dish, or on a cooked rice.
1. If you don't have bonito flakes, you can use a small amount of dashi powder. If you don't have dashi powder either, you can omit it. The umami flavour of the marinade is not as strong, but ramen eggs are still tasty.
2. I sprinkle leftover bonito flakes over a bowl of cooked rice just like furikake. It's so delicious.
3. Boiling for 6½ minutes makes the egg yolk runny in the centre and semi-cooked around the edge. Boiling eggs for 7 minutes makes the egg yolk semi cooked but not runny, and 6 minutes will make almost the entire egg yolk runny, while the egg white is quite soft.
4. It is important to quickly cool the eggs down to stop further cooking with residual heat.
5. Place the eggs with the round side of the egg up in the egg carton. Using a needle and a small hammer or the side of a pair of kitchen scissors, gently.
6. You can use a small knife to halve the egg as well, but a thread makes a cleaner cut especially when the yolk is runny.