Onsen Tamago (Hot Spring Eggs)

Onsen Tamago (Hot Spring Eggs) are poached or soft cooked eggs in warm water. They have a silky custardy consistency delicious eaten with rice or noodles.

In Asia eggs are not confined to the breakfast menu but are used liberally during lunch and dinner as well. It is a good inexpensive source of protein that lends itself to many different ways of preparation. It also cooks up really fast.

Eggs are very versatile. They can be cooked into a simple side dish like this Omelet with Chives and Onions or simply fried to enhance a main dish in the form of a topping as seen in this Kimchi Fried Rice. Either way it is quick, easy, comforting, and delicious.

Today’s Onsen Tamago (Hot Spring Eggs) is the epitome of egg simplicity and deliciousness all wrapped in one. These gently poached eggs can be served on its own in a small bowl with a soy dashi broth for breakfast. They are also often used as a topper for rice or noodle bowls eaten during lunch or dinner.

Onsen Tamago (Hot Spring Eggs) is said to have traditionally been cooked in the consistent sub-boiling geothermal springs in Japan. The eggs are lowered into the spring waters to gently poach to a silky and custardy consistency, hence its name. This could take up to 40 minutes or more. Fortunately, we do not need a hot spring to prepare these eggs nor wait so long to enjoy them. This process can be replicated in the kitchen quite easily and in a shorter time with the use of a kitchen thermometer and timer.

For those of you in Malaysia and Singapore who are familiar with Half Boiled Eggs, please note that Onsen Tamago is just ever so slightly firmer. When the cooked egg is cracked open, it rolls out into an almost cohesive ball. Sometimes described as an “inverted poached egg”, the yolk is supposed to be custard-like and slightly firmer than the white. Half boiled egg on the other hand, is a little more runny with the egg white spreading out in the bowl.

There are many different methods used in preparing Onsen Tamago. I found this one which tried to maintain the water temperature at around 167˚F (75˚C) for 13 minutes. Depending on your stove, you may have to adjust the time slightly. After several tries using two different stoves, I had pretty consistent results.

My main stove is an electric stove and I had a hard time maintaining the water temperature at 167˚F (75˚C). The initial water temperature always ended up higher at around 168˚F – 170˚F (75˚C – 77˚C). Because of that I had to modify the method and timing slightly which I explained in the video. Then I tried the method again using my portable gas stove and had to adjust accordingly. Likewise, you may have to try a few times to get it just right on your stove.

Always use the best and freshest eggs you can find when making Onsen Tamago. Fresh eggs tend to sink to the bottom of the saucepan and will be submerged in the water. I use only organic brown eggs in my kitchen.

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Onsen Tamago (Hot Spring Eggs)

Prep Time

3 mins

Cook Time

12 mins

Total Time

15 mins

 

Onsen Tamago (Hot Spring Eggs) are poached or soft cooked eggs in warm water. They have a soft creamy consistency delicious eaten with rice or noodles.

Course: Side Dish

Cuisine: Japanese

Servings: 2

Calories: 91 kcal

Author: Linda Ooi

Ingredients

• 2 large eggs (at room temperature)
• 1 green onion (thinly sliced)

Sauce

• 1/3 cup water (80ml)
• 1/8 tsp dashi
• 1 tbsp mirin
• 1 tbsp soy sauce

Instructions

Method 1 – using electric stove

1. Heat up a small saucepan of water (sufficient to submerge eggs) to approximately 168˚F to 170˚F (75˚C to 77˚C). At that temperature, you should see tiny bubbles in the water. Turn off the stove but leave the saucepan on the heated element.

2. Gently lower eggs with a ladle into the warm water. Do not cover saucepan. Set timer to 11 minutes.

3. After 6 minutes, water temperature would have dropped to about 166˚F (74˚C). Cover the saucepan with lid and continue to leave it on the heated element.
4. After 11 minutes, remove eggs with ladle into a bowl of cold water to stop the cooking.
   
5. Crack each egg into individual bowls. Drizzle with prepared sauce and garnish with sliced green onion.
   

Sauce

1. While eggs are poaching, prepare the sauce.

2. Combine water, dashi, mirin, and soy sauce in a small saucepan. Bring to a gentle simmer. Stir to mix. Turn off stove. Transfer to a serving dish.
   

Method 2 – using gas stove

1. Heat up a small saucepan of water (sufficient to submerge eggs) to approximately 168˚F (75˚C). At that temperature, you should see tiny bubbles in the water. Reduce the flame to the lowest possible setting sufficient to maintain the water temperature at 166˚F to 168˚F (74˚C to 75˚C).

2. Gently lower eggs with a ladle into the warm water. Do not cover saucepan. Set timer to 12 minutes.

3. After 12 minutes, remove eggs with ladle into a bowl of cold water to stop the cooking.
   
4. Crack each egg into individual bowls. Drizzle with prepared sauce and garnish with sliced green onion.
   

Onsen Tamago is especially delicious served with rice. Do give it a try.

Enjoy…..and have a wonderful day! 😎