In the past, I’ve shared some popular Japanese egg recipes on Just One Cookbook such as Omurice, Tamagoyaki, and Ramen Egg (Ajitsuke Tamago). Today I’ll add another popular dish to the egg recipe collection, and it’s Onsen Tamago (温泉卵).

Watch How To Make Onsen Tamago

Originally prepared in hot spring water in Japan, this delicious egg recipe with soft silk egg whites and custard-like yolk is easy to make at home.

What’s Onsen Tamago?

Onsen means hot springs, and tamago means eggs in Japanese. Why is the name “hot springs eggs”? Originally, eggs that were prepared this way were slow-cooked in Japan’s warm hot springs water. What’s so special about these eggs? These eggs are perfectly poached inside its shell. While the whites are soft and silky, the yolk comes out firm but retains the color and creamy texture of an uncooked yolk. It’s basically the complete opposite of soft-boiled eggs that are firm whites and soft egg yolk.

The Chemistry Behind Onsen Tamago

This special texture is achieved because egg yolk and egg white solidify at different temperatures. Egg yolks solidify at 158 degrees °F (70 °C) and egg whites solidify at 176 degrees °F (80 °C). Therefore, if we maintain the cooking water to be at 149-154 degrees °F (65-68 °C), we’ll get a perfect spherical poached egg, creamy and silky on the outside and firm on the inside.

This Recipe Works for EVERYONE.

There are many ways to make the perfect onsen tamago, but this technique does not require a microwave, a thermometer, or any special cooking gadget. Here are the highlights of this technique:

Requires just a stove and pot (which I hope everyone has in their kitchen).Does NOT require a thermometer.Use refrigerated eggs. Some recipes require eggs to be “room temperature”, but the “room” temperature could be different depends on where you live.Not required to soak eggs in iced water after cooking, in case you don’t have ice cubes handy.

If you follow my recipe precisely, you should be able to achieve perfect onsen tamago as the final result. The only requirement is to use 4 large eggs. If you use different size eggs or reduce/increase the number of eggs, it will not work as the water temperature will change.

How Do you Enjoy Onsen Tamago?

You can enjoy onsen tamago with a dashi-based soy sauce (だし醤油) which is usually served as a part of Japanese breakfast. Also, you can place it on top of the steamed rice, splash some soy sauce over, mix and enjoy; serve with gyudon, curry rice, soba noodle soup, and cold udon; or even mix with carbonara (my favorite!). Now let’s get started! The best part about this recipe is you do not need to visit hot springs in Japan to enjoy these special eggs. Make the perfect onsen tamago right at home! Disclaimer: Many people in the world including the Japanese consume uncooked eggs in their cuisine. However, according to the FDA, eggs should be cooked to 165 degrees °F (74 °C) in order to be considered safe. The perfect temperature for cooking onsen tamago is 149-154 degrees °F (65-68 °C), which is below the guideline. There is a risk of salmonella with consuming undercooked eggs. Wish to learn more about Japanese cooking? Sign up for our free newsletter to receive cooking tips & recipe updates! And stay in touch with me on Facebook, Pinterest, YouTube, and Instagram.