Onsen Tamago (Hot Spring Eggs) are soft cooked eggs in warm water. They have a deliciously silky and custardy consistency.
In Asia people eat eggs throughout the day, not just for breakfast. It is a good and inexpensive source of protein that lends itself to many different ways of preparation. It also cooks up really fast.
The Versatile Egg
Eggs are very versatile and easy to cook. You can simply fry an egg as a topping like this Kimchi Fried Rice. If you prefer a fancier omelet, try this Omelet with Chives and Onions. Either way it is quick and easy to prepare, yet delicious and comforting.
Today’s Onsen Tamago (Hot Spring Eggs) is the epitome of egg simplicity and deliciousness all wrapped in one. You can serve these gently cooked eggs on its own in a small bowl with a soy dashi broth or as a topper for rice or noodle bowls.
Onsen Tamago
Traditionally, Onsen Tamago (Hot Spring Eggs) are cooked in consistent sub-boiling geothermal springs in Japan. The eggs are lowered into the spring waters to gently cook 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 using a kitchen thermometer and timer.
Half Boiled Eggs
In Malaysia and Singapore most people are familiar with Half Boiled Eggs which have runny egg whites spreading out in the bowl. 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 custard-like and slightly firmer than the white.
Different Methods of Preparing Onsen Tamago
There are many different methods of preparing Onsen Tamago. I found this one which maintains 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.
Using An Electric Stove
My main stove used to be 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). As such, I had to modify the method and timing slightly.
Using A Gas Stove
Then, I tried the same method using my portable gas stove and I had to adjust the timing accordingly. Likewise, you may have to try it a few times to get it just right on your stove. Please watch the video for further explanation.
Best Results With Super Fresh Eggs
Always use the best and freshest eggs you can find when making Onsen Tamago. Fresh eggs sink to the bottom of the saucepan and will be fully submerged in the water. I use only organic brown eggs in my kitchen and they work well for this recipe.
Similar Tools Used in Making These Onsen Tamago (Hot Spring Eggs)
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Portable Gas Stove with Carrying Case
Saucepan with Vented Tempered Glass Lid, 1-Quart, Stainless Steel
Stainless Steel 1-Quart Saucepan with Glass Lid and Tri-Ply Bottom
Digital Instant Read Thermometer
Onsen Tamago (Hot Spring Eggs)
Ingredients
- 2 large eggs (at room temperature)
- 1 green onion (thinly sliced)
Instructions
Method 1 – using electric stove
- 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.
- Gently lower eggs with a ladle into the warm water. Do not cover saucepan. Set timer to 11 minutes.
- 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.
- After 11 minutes, remove eggs with ladle into a bowl of cold water to stop the cooking.
- Crack each egg into individual bowls. Drizzle with prepared sauce and garnish with sliced green onion.
Sauce
- While eggs are poaching, prepare the sauce.
- 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
- 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).
- Gently lower eggs with a ladle into the warm water. Do not cover saucepan. Set timer to 12 minutes.
- After 12 minutes, remove eggs with ladle into a bowl of cold water to stop the cooking.
- Crack each egg into individual bowls. Drizzle with prepared sauce and garnish with sliced green onion.
Notes
Nutrition
Serving Suggestion
Onsen Tamago makes a delicious topping for rice and noodles. Do give it a try.
Susanna says
Hi Linda. Did you use room temp eggs or straight form the fridge for your I sent eggs?
Linda says
Eggs should be at room temperature as specified in the recipe.
Susanna says
Thanks Linda ?